Official Blog of Silicon Labs

    Publish
     
      • Choosing Electronic Parts for Your Project - Part 3

        lynchtron | 08/244/2016 | 10:09 AM

        electronic_parts_header.png

         

        In this final part of a three-part series about how to pick electronic parts for your electronic project, we will learn about actuators, a few categories or integrated circuits, and power regulation circuit components.  This overview is really just a drop in the ocean of parts at your disposal.  Component manufacturers are always inventing something new to complete with each other.  This brief overview is only intended to give you an idea of what exists, so that you will be more likely to find what you are looking for.  Happy hunting!

         

        Actuators

        Actuators give our gadgets the ability to interact with the outside world.  These are the things that robots and autonomous vehicles require to move and do work.  They are controlled through the presence of a prescribed voltage or a communication interface.

         

        Electromechanical solenoids convert a voltage into a linear motion through the use of a wire wound around a moveable magnetic armature.  They have two states of “open” or “closed” and are actuated by the presence of voltage, which causes the magnet to move away from the resulting electric field.  When the voltage is removed, a spring returns the magnetic armature to the starting position.  Solenoids are normally used for temporary motions, since they consume power whenever they are in one of the available two states.  They can be powered by either DC or AC voltages.

         

        Audio Speakers are solenoids that are connected to paper, plastic or metal cones and placed in an enclosure to move air.  This creates pressure changes that result in sound or other types of vibrations.

        DC motors utilize the small available voltages of an MCU-powered gadget to create rotation.  The relative speed can be controlled with Pulse Width Modulation (PWM) as long as the load on the motor is known.  If the load on the motor is unknown, the speed of the motor will not be constant over the PWM range.  In that case, an encoder device is used to give the necessary feedback to the MCU in order to adjust the PWM value to give the rotational speed required.

         

        AC motors allow higher speeds and torque than DC motors due to the 120 to 240V voltage available at the wall socket, plus up to 15 or 20A of current.  AC motors can be controlled by the MCU via relays that isolate the large AC voltage from the small DC voltage that runs the MCU.  

         

        Servo motors allow a measured rotation of an arm around a central axis.  Like the DC motor, the servo is controlled via a PWM waveform, but in this case the duty cycle of the PWM waveform is used to control the rotational angle of the servo.  The servo maintains its angular position as long as the control PWM waveform is applied.  Servos are quick to actuate and are used to control the wheels and rudders on remote-controlled toy cars, airplanes, and boats. 

         

        Stepper motors are similar to servos but operate on a different principle.  They are generally slower to actuate than servos but can maintain their angular rotation even after the control signal is removed and require no feedback to determine the angular position.  If used within the torque loads defined in its specification, a stepper motor can be controlled simply with a number of pulses from the MCU.

         

        Integrated Circuits (ICs)

        Integrated circuits (ICs, also known as semiconductors or simply “chips”) are the components in your design that will add logic and programmability to your project.  These chips are simply bundled versions of all of the foundational electronic components described above.  Therefore, many of these ICs can be built on your PCB from a collection of those same discrete components, but the resulting size of the circuit could be prohibitive due to the number of components needed.  For example, the microprocessor in your home computer contains over one billion transistors, as well as on-chip capacitors, inductors, resistors, diodes, and other basic circuit elements. 

         

        Logic gates can offer basic logic operations such as AND, OR, NOT, XOR, etc.  These components are the basis of all integrated circuits that follow.  But they can be helpful to use on the circuit board when you are trying to save pins on the MCU.  For example, suppose you have a safety mechanism which requires two buttons to be pushed at the same time for some function in your device to activate, like the self-destruct sequence, or maybe just resetting the gadget to the default state.  Rather than use two pins on the MCU, you can combine the two inputs through an AND gate, and then a single GPIO pin on the MCU can be used to detect activity on two buttons at once, but only if they are both being pressed at the same time.

         

        Optoisolators are a combination of a photo diode and photo transistor in the same package.  These devices are the simple combinations of exactly two discrete components.  They provide electrical isolation of two circuits, using only light as the bridge between electronic circuits.

         

        Digital potentiometers provide adjustable resistance to a circuit via digital interface such as I2C or SPI.  They can be ordered according to the absolute resistance range available, number of programmatic steps, and accuracy.  This is a way to add a software programmable resistance value to your circuit.

         

        Amplifiers can be formed with a single transistor but can also be in the form of ICs that create operational amplifiers (OpAmps), specialized to power regulation purposes or for high fidelity applications such as audio.


        Multiplexers (or Muxes) are components that combine the functions of many logic gates to create an input selection device.  The mux will sample its control lines to determine which input pin voltage is connected to the output pin.  These devices can be used in an audio mixer to select a single source signal from a set of possible input sources.

        a2_mux.png

         

        Demultiplexers (or Demuxes) perform the opposite function of muxes.  The control pins specify which output pin is assigned the voltage present at the input pin.  They are normally used at the receiving end of a signal that was previously multiplexed. 

         a2_demux.png


        Decoders provide a translation from a set of input pins to a set of output pins.  This device can translate a number encoded on the inputs into a single output that is the value of the number.  For example, a 2-to-4 decoder can accept a two-digit code and assert only one output depending on the value of number represented by the four pins.  These can be useful to save pins on the MCU.

         a2_decoder.png


        Encoders perform the opposite of decoders, allowing many signals to be compressed into a combinatorial that effectively compresses the number of pins needed to read the values of many inputs.  Again, these can save pins on the MCU.

         a2_encoder.png

         

        GPIO expanders give the designer more GPIOs than what may be available on the MCU.  The interface to the MCU is typically I2C or SPI, and can be configured as input or multiple types of outputs such as open-drain, push-pull, etc.   These devices can allow full bidirectional, full-time control of each additional GPIO line, unlike muxes, demuxes, encoders and decoders.  GPIO expanders might also give the designer special features such as higher current capacity and PWM-capable GPIOs that can all be configured through configuration registers.

         

        Analog-to-Digital Converters (ADC’s) and Digital-to-Analog Converters (DAC’s) are available in the EFM32 family as onboard peripherals, but can also be used as an external IC with an I2C or SPI interface.  This allows the designer the ability to pick higher-resolution converters or simply add more ADC’s to the design.

         

        Audio chips are available that can convert digital encoded (PCM) audio into PWM output waveforms through a bus interface called I2S.  Some audio devices have onboard amplification for direct connection to a speaker.  Sound effects chips contain onboard non-volatile storage, such as ROM or flash memory, that stores sounds onboard for later playback from the MCU and may also record audio from a microphone.

         

        Display chips allow the control of display screens through I2C, SPI or parallel interfaces.  The EFM32 family has several interfaces available for controlling some types of displays.  Some display chips contain non-volatile storage with built-in handling of resistive and capacitively-coupled touch screen interfaces and can contain coprocessors for rendering images from MCU instructions without burdening the MCU with the pixel-by-pixel computations.

         

        Interface and Communication chips provide a way to connect the MCU to the outside world through standard, widely available interfaces such as Ethernet, UART, USB, RS-232, or even I2C or SPI bus expanders and hubs.

         

        Radio Frequency (Wireless) chips and modules allow your gadget to connect your gadget without wires through standards such as Bluetooth Low Energy (BLE, also known as Bluetooth Smart), ZigBee, WiFi, and mobile networks, as well as to non-standard devices such as garage door openers and radio-controlled toys.  Note however that any design sold to end users (not for kit or evaluation purposes) that broadcasts RF energy needs to be licensed by the FCC, which is an expensive process.  A pre-licensed module can avoid that process, albeit with higher component cost.

         

        Memory chips add additional volatile and non-volatile memory to your design.  Volatile memory, typically Random Access Memory (RAM), will not retain its state after the power is removed and is typically used for a fast holding place for large sets of information.  Non-volatile memory, such as flash memory, will retain its state after power is removed, but can be slower to write or read.  The EFM32 family of MCU’s is ordered according to the amount of both RAM and flash memory that is built into the MCU.

         

        Programmable Logic Devices (PLD’s) offer custom on-chip logic.  This device allows the designer to create custom combinatorial logic circuits right on the chip itself through the use of a programming-like language.  This has the benefits of fast execution and offloading the MCU from making timing-critical computations on hardware signals.

         

        Power Regulation ICs

        All components in your gadget consume some amount of current at a prescribed voltage range, so it is often required to convert voltages in order to supply the right kind of power for each component.  Devices that connect to a wall socket for power can utilize alternating current (AC) power in the 120 volt to 240 volt range that deliver up to 15 amps of current.  This is useful for driving powerful motors or heaters, for example.  However, any integrated chips (ICs) that are necessary to control the device and give it smarts will require that the AC power is converted to direct current (DC) voltage.  This can be accomplished in a single step through the use of an off-the-shelf AC/DC power supply, also known as a “wall wart”, available in a wide range of voltage and current outputs.  The most typical AC/DC converters to be used for EFM32 projects is a 3.3V supply, since the EFM32 operates in a range of 2.5V to 3.6V.  Once the 3.3V supply is provided to the gadget, all components that require power will have to be chosen such that they can operate on that same voltage.  Often, some devices chosen for the design will require a higher or lower voltage.  When there is a need for more than one required voltage on a single board, a voltage regulator chip will be required to convert the voltage for those devices.


        Any electrical component that operates directly from a battery must be chosen such that the full range of battery power is permissible for the device.  For example, a pair of fresh AA batteries create a maximum of 3V but drop down to about 2V when depleted.  In addition, any battery will see a drop in voltage when under a heavy current load. All of this must be considered when picking components that can handle the lifetime voltage range.  For example, many LEDs have a forward voltage of around 3.2V.  When the batteries start to drain and can’t provide the correct forward voltage, the brightness and even the color shade of the LEDs can change unless the battery voltage is further regulated to a standard onboard voltage.

         

        battery_drain.png

         

        Regulators can be fixed or variable output.  The fixed regulators can accept a fixed or variable input voltage but deliver a factory-set output voltage.  A variable regulator might accept a fixed or variable input but produce a variable range of output voltage, typically set via configuration resistors.  Some advanced regulation chips can utilize programmable interfaces such as I2C or SPI to set the output voltage.  

         

        The following types of regulators can help you supply all of your components with the proper voltage.  All voltage regulators have a limit to the amount of current that can be delivered, which is part of the component specification.

         

        Linear regulators convert a higher voltage to a lower voltage and waste energy in the form of heat in the process, but can deliver clean power with no added noise.  They can be effective if the amount of power delivered is very small and the voltage difference between input and output voltage is small.  For example, a component that requires 2.5V and only consumes 5mA of current could very well use a 3.3V to 2.5V linear regulator.  The wasted power would be 0.2V x 5mA = 1mW.  This could be good for some applications but would be an unacceptable power draw for a device that runs on the tiniest of batteries or energy harvesting.  The main reason to use a linear voltage regulator is to keep the output as ripple-free as possible.

         

        Low Dropout (LDO) regulators are linear regulators that are designed to output a voltage that is very close to its input voltage.  Normal linear regulators specify a larger delta between the input and output voltage.  The “dropout” is the voltage difference between the regulator input voltage and output voltage.  

         

        Zener Diodes provide a special-case way to regulate the output voltage linearly by simply capping the amount of voltage that is present at the pins of the diode.  It does this by shunting excess current to ground to maintain a required voltage.

         

        Switching regulators utilize digital clocks and output stage filters (inductors and capacitors) to efficiently convert an input voltage to an output voltage.  The design improves power efficiency and are more complex and expensive than linear regulators but can create unwanted noise, particularly if the output stage filters are not chosen carefully for high quality.  They generally require a large, high-quality inductor to filter the resultant voltage.

         

        Buck regulators (also known as step-down regulators) are a type of switching regulator that requires a higher input voltage than the output voltage.

         

        Boost regulators are a type of switching regulator that requires a lower input voltage than the output voltage.

         

        Buck-Boost regulators are a type of switching regulator that have no constraint of the input voltage versus the output voltage and provide both buck and boost functions in one device.

         

        Charge Pumps are capacitor-based switching regulators that have high efficiency under low current load and are typically low cost, as they do not require an inductor.

         

        This wraps up the chapter on component selection.  You should now possess the necessary lingo to at least begin to browse the universe of components available today.  

         

        PREVIOUS | NEXT

      • The Importance of Timing in Today's Content Landscape

        Lance Looper | 08/243/2016 | 03:24 PM

        Before the Rio Olympics kicked off, we talked about how the Internet of Things would be utilized to improve things like judging some of the events and tracking athletes tracking during the marathon. But even beyond IoT, Brazil’s technology game was strong. Digital coverage of the Olympics set a record with 3.3 billion minutes of total content streamed, with 2.7 billion minutes of that happening live. These numbers mean the 2016 Rio Olympics were likely the most streamed event in history, with more than 100 million people streaming games-related content over two weeks.

         

        That doesn’t happen without some serious timing and synchronization.

         

        Track_Timing.jpg

         

        The Lifecycle of a Video Signal

        Live, televised events typically utilize a number of cameras to capture the action from various angles. This is especially true for sporting events, where different cameras follow the action around a field of play. Cameras capture the images by converting light into electrical signals. Horizontal, vertical, and field synchronization (HVF) information is then added to the signals so the receiver is able to identify the edges of the frame. All of these signals, which are being generated and transmitted simultaneously, need to be synchronized in order to seamlessly switch between sources without buffering.

         

        We’re only scratching the surface, but you can see going from source to final broadcast takes a lot of engineering. And bringing the action from the beaches of Rio to the comfort of your living room requires a lot of components, from switchers that coordinate multiple video sources including cameras and storage devices to distribution amplifiers that beam video signals around the studio and beyond. There are also timing generators and frame synchronizers that synchronize each source, as well as routers that provide a single point for switching signals to and from other studios. As if that’s not complicated enough, many of these components need to support multiple standard and high definition video formats available today.

         

        Signal Lifecylce.png

         

        More than one hundred million people streamed the Olympics online, which means each one had an individual data stream. With proper timing, the broadcast signal is being sent and received like clockwork. When it begins to break down, for example if the router between the broadcast TV studio and the network is overloaded, the timing of the signal delivery is thrown off. If you’re watching a movie, the result can be that the picture freezes for a second or the service will stop to buffer content. This is annoying, but if you’re watching a sporting event that might be decided by seconds, these kinds of delays kill the user experience.

         

        Servers.png

         

        Meeting the Growing Needs of Video Transmission

        Think of these timing components as the conductor of an orchestra, but instead of dozens of instruments on a stage, it’s coordinating millions of data streams around the globe between the broadcast video studio and the device you’re streaming to. This is where Silicon Labs comes in.

         

        Our oscillators, jitter attenuators, clock generators and clock buffers are used virtually everywhere video synchronization is needed, including supplying the world’s leading internet equipment suppliers.  Content providers, whether it’s a television network or a movie streaming service, rely on networks that can deliver great viewing experiences for their subscribers. 

         

        This is where we come in. Our portfolio includes the industry’s most comprehensive timing portfolio. Like the orchestra’s conductor, our timing products set the beat for Internet traffic by coordinating the content exchange between service providers and consumers.

         

        Timing Portfolio.png

         

        Oscillators

        Our crystal oscillators and voltage-controlled crystal oscillators (XO/VCXOs) utilize advanced DSPLL circuitry to provide a low jitter clock at any frequency from 100 kHz to 1.4 GHz. Silicon Labs offers single, dual, quad, and I2C programmable frequency XO/VCXOs, enabling a single device to replace multiple XO/VCXOs.  This IC-based approach delivers exceptional reliability, while providing best-in-class jitter performance and supply noise rejection, simplifying the task of generating low-jitter clocks in noisy environments.

         

        Jitter Attenuators

        In video applications, Silicon Labs jitter attenuators provide Genlock support, enabling effective video synchronization across different studio equipment. Our jitter attenuators generate any combination of output frequencies from any input frequency with industry-leading jitter performance. Based on our 4th-generation DSPLL architecture, these devices simplify clock tree design by replacing multiple clocks and oscillators, minimizing BOM count and complexity.

         

        Clock Generators

        Silicon Labs’ highly flexible clock generators can be customized to generate any combination of output frequencies from any input frequency.  In addition to providing industry-leading frequency flexibility, Silicon Labs’ clocks deliver best-in-class jitter performance, lower power, and smaller size. These flexible devices are designed to replace multiple oscillators and fixed-function clock ICs, enabling multiple components to be replaced with a complete clock-tree-on-a-chip.

         

        Clock Buffers

        Our family of low-jitter clock buffers support any signal format in/out, providing flexible format translation in addition to low jitter, low skew clock distribution.  This flexibility reduces BOM complexity by allowing the same device to be used across multiple projects and platforms.

         

        To learn more about our timing and synchronization portfolio, click here. 

         

      • Trick Out Your Minecraft with the BGM111

        Lance Looper | 08/239/2016 | 03:18 PM

        Minecraft. If you haven’t heard of it, it is a sandbox game. There is no objective, other than to survive. There is no linear story, no final boss, and no limits. It has been such a hit that companies like Lego are selling branded kits. Minecraft. Build what you want, where you want. You are free to do as you want, but watch out, when the night comes, you find out that you aren’t alone. You need light to survive, and one of the first things you will make are torches. Torches make light, and keep the bad things away; zombies, spiders, creepers, managers, bosses…

         

         

        I’m a Minecraft fan. I love the freedom the game gives me, and I like the retro feel. I like it so much that I have some Lego Minecraft sets on my desk, and while they are awesome, they needed something more. I wanted the torches to light up, keeping managers and bosses at bay. I wanted the lights to turn on automatically when I arrived, and turn off when I leave. Yes, I could have put a switch in, but Bluetooth gives me the freedom to detect my presence, and without wires. So let’s see what a Silicon Labs Blue Gecko Wireless Starter Kit and a few boxes of Legos can do!

         

        Minecraft + Lego

        Let’s take a closer look at the Lego kits. It’s all there, from the small hut that will let you survive your first night, to the zombies that want to eat you, and the creeper who wants to blow you up. And, of course, a Minecraft kit wouldn’t be complete without torches. When building the kit, I noticed that the torch was hollow, and that the base was roughly 3mm in size, perfect for a small LED. Using a breadboard, a resistor, a white LED, and a little bit of putty, I noticed that the light could shine through, adding a warming glow to the kit. However, torches aren’t stable light sources, they tend to flicker, so it was time to investigate.

         

        To simulate a flickering candle, you normally need two red LEDs and a yellow or orange LED. Three LEDs don’t fit, and besides, the transparent bricks on the top already change the color, so I had to make do with a single white LED. PWM came to mind. By modifying the frequency, I could get the LED to change brightness, and by repeating that often enough, it could look as if it flickered. The problem is, the BGM111 doesn’t have PWM output. It does, however, have an easily accessible I2C port, so I went looking for PWM expansion cards.

         

        Minecraft BGM111.png

         

        Adafruit to the Rescue

        The Adafruit 16-channel 12-bit PWM board was a perfect fit for my needs. It is small, but feature packed. It can handle up to 16 LEDs using a single I2C address, and the address is easily changed. Also of interest is the built-in 220-ohm resistor for each output. This makes LED driving trivial; just plug in the LED, and you’re good to go. Oh, and it’s made by Adafruit, so you know it’s well designed, and has excellent source code available.

         

        I ordered one, and it arrived the next day. Solder time! The board has 16 3-pin outputs; V+, GND and PWM. It doesn’t get much easier than this. On the left and right of the board are the power and data connectors, designed so that they can be chained together. Adafruit says that you can chain 62 board together, for a total of 992 PWM outputs. Adafruit, if you are listening, I’m interested in giving this a shot!

         

        Adafruit_Board.png

         

        Before putting that soldering iron away, don’t forget to change the board’s I2C address. The temperature sensor on the WSTK uses address 0x40, so change the Adafruit address to something else. For this one, I used 0x41, and maybe I’ll get my hands on a few more later on.

         

        Blinky Things!

        It’s time to connect. The SDA/SCL and power pins are clearly marked on the Adafruit board, and if you turn the Silicon Labs board over, you can see the pinout for the expansion header. The green LED on the Adafruit should light up, telling you the power is OK. Now it’s time to work on the software.

         

        I wanted to get things up and running as fast as possible, so I used BGScript. It has everything needed to accept connections, talk to I2C peripherals, and use timers. Before working on the connection side of things, I wanted to get the I2C communications up and running. Adafruit supply a nicely written library for Arduino, which is a great start.

         

        The PCA9685, the chip that powers the Adafruit board, can have PWM outputs that start and end at different times compared to the other outputs. It therefore requires two parameters; when to turn on, and when to turn off. If I needed an output to start slightly later than another one, this would be a great feature, but I don’t need it. The PCA9685 has a counter that starts at 0 and ends at 4095, within this period, you can tell the driver when to turn on, and when to turn off. To make things simple, I’ll be turning the LED at 0, and then randomly telling the LED when to turn off by creating a random number between 0 and 4095.

         

        To send this information, you must send 5 bytes on I2C. The first one is the LED; which LED are we talking to? The base address is 0x06, and each LED has 4 bytes of data, so we’ll be using register 0x06 + (LED * 4). The next two bytes specify when we need to turn the LED on; since we’ll be turning it on immediately, we can leave these two at 0. Next, we tell the controller when to turn the LED off. This is done by creating a random byte using system_get_random_data(), and then multiplying that by a certain number to achieve a maximum of 4096; 16. The problem with this is that the LED can be anywhere between full brightness and completely off, which isn’t what a torch looks like. I simplified this by starting off at 2048, half of the maximum number, and then adding a random byte times 8. This gives me a value anywhere between full brightness and half brightness, which does look better. Then we have to send this to the controller, using shifting. This data will be put inside a buffer.

         

        The end code looks like this:

         

        Screen Shot 2016-08-26 at 1.49.23 PM.png

         

        Next, you have to send this on the I2C bus:

         

        Screen Shot 2016-08-26 at 1.50.39 PM.png

        Now that this is done, all we need to do is to create a for loop for each LED.

         

        Allowing Connections

        I want this kit to light up, but only for the device that I want. Also, I don’t want to go through the pairing process every time I arrive at the office, that would be a waste of time. With Bluetooth, you can “bond”, that is to say pair and remember the pair, so that the next time, the two devices connect together automatically. Bonding is slightly complicated, but the BGM111 module handles all of that for you. All you need to do is to specify what mode you would like.

         

        First of all, we need to make sure we can connect, so let’s add that command:

         

        Screen Shot 2016-08-26 at 1.52.20 PM.png

         

        This will set up out device to be connectable, but not discoverable. If we have already connected to this device, then we should be able to connect automatically, otherwise we won’t be able to see it. To advertise our presence, we need to change the command slightly:

         

        Screen Shot 2016-08-26 at 1.53.22 PM.png

         

        This puts the device into limited discoverability mode, meaning it will be visible to scans for just over a minute. Finally, to enable bonding, use this command:

         

        Screen Shot 2016-08-26 at 1.54.18 PM.png

         

        With all that, all that is left to do is to look at the state of a pushbutton when starting up (or resetting). Let’s try this:

         

        Screen Shot 2016-08-26 at 1.55.45 PM.png

         

        Connecting and Disconnecting.

        Luckily, BGScript makes this easy. The module will handle everything, and just tell you when someone connects, using an event. When an authorized device connects, the event le_connection_opened is called, so let’s use that. When a connection is made, we want the LEDs to blink, so we need to do two things. First, we need to set up a timer, something that will be called every few milliseconds. Next, when this timer is called, we want to use the LED program we created earlier on. No problem! Let’s do it. To create a timer, you simply write this:

         

        Screen Shot 2016-08-26 at 1.57.46 PM.png

         

        This creates a timer, using the TIMER_PWM “channel” (created previously as a const). The timer is now set, and another event will occur when the timer “ticks”: event hardware_soft_timer(handle)

         

        Now, using an if statement, we can tell the board to blink:

         

        Screen Shot 2016-08-26 at 1.59.32 PM.png

        When a device disconnects, another event is generated, this time called le_connection_closed. Since only one device will be connected, we can safely shut down everything. First, let’s stop the timer. Just call the same timer code as before, but leave the timeout at zero:

         

        call hardware_set_soft_timer(0,TIMER_PWM,0)

         

        Next, we need to call the same blinky code, only this time, we need to set everything to zero to make it stop blinking:

         

        Screen Shot 2016-08-26 at 2.02.11 PM.png

         

        Finally, don’t forget to allow connections again! When a connection is made, the Silicon Labs module no longer accepts connections, and it is up to you to accept them or not. We didn’t want to, but now that no-one is connected, it is time to enable them again, so that my laptop can connect again when I arrive in the office (or, in my case, I turn it on again).

         

        Screen Shot 2016-08-26 at 2.03.18 PM.png

        Minecraft Fun.png

         

        And that’s it! Time to flash the code to a Silicon Labs device, and to start it up! On first boot, you need to press down PB1 to set it to discoverable mode, but after that, it should be fully automatic. If you can’t press PB1 down when the board is powered, you can use the reset button; the event is called when the system starts, either by a cold boot, or warm boot. And that’s it! Now that my Lego torches are protecting me from creepers, zombies, bosses and furious kittens, I’m safe to work!

         

        Source code available on GitHub: https://github.com/jlangbridge/BluetoothInAction

         

      • Choosing Electronic Parts for Your Project - Part 2

        lynchtron | 08/238/2016 | 10:49 AM

        electronic_parts_header.png

        This is Part 2 of a series on all of the available parts for your electronic project.  In the last post, you learned about the fundamental circuit elements common to all electronic gadgets.  We continue our overview in this lesson, with a look at switches, connectors, and sensors.

         

        Switches

        Switches are used to connect or disconnect a circuit element and are employed in power buttons, light switches, keyboards, mice buttons, multifunction buttons, slide switches, and more. 

        Switches often refer to a pole and a throw.  The throw refers to the mechanical action, i.e. the button or lever.  The pole is how many electrical terminals are on one side of the switch.  A single pole device (also known as a two-way switch) can only connect two sides an electrical circuit together or disconnect the circuit.  A switch that has a double pole (also known as a three way switch) means that the switch can connect one side of the circuit to two possible terminals on the other side.  Finally a switch that has two poles and two throws is actually two switches built into a single device.  This can be useful if two different circuits both need to be switched at the same time, for example if an AC supply voltage and DC supply voltage both need to be controlled simultaneously.


        Push-button switches or momentary switches have a spring inside that allow the switch to be switched on or off momentarily and when released, the spring will allow the circuit to return to the default state.  Such switches vary greatly in size, mounting styles, packages, and number of cycles before failure. 

         a2_switch.png


        Dip switches are slide switches that can be used to configure electronic circuits.  The small switches require a sharp instrument such as a pen or tweezers to slide the plastic sliders into position, which configures an option in a circuit.

        a2_dip_switch.png
         
        Tilt switches can detect when the gadget is tilted beyond a certain angle, which closes the circuit, allowing current to flow.  These devices allow the electronic gadget to detect something about its physical orientation in space.

        a2_tilt_switch.png


        Vibration switches contain a metal ball suspended inside a metal housing with insulating springs.  When the device is shaken, the switch closes momentarily when the ball touches the housing.  The switch can be ordered in a variety of sensitivities and is known as the poor maker’s accelerometer.

        a2_vibration_switch.png


        Reed switches connect its terminals in the presence of a magnetic field.  These can be used with a magnet to detect when a door has been opened or closed.

        a2_reed_switch.png

         

        Relays are switches that are controlled by an external voltage source.  This allows an MCU to control any voltage that can be external to the gadget.  Relays are typically used to allow the MCU to control much higher voltages, such as automotive 12V DC or household 120V AC power.  When ordering relays, you must specify the control voltage as well as the operating voltage across the switch, and the isolation between the switched voltage and the control voltage.  You wouldn’t want a high voltage to get through the switch to fry your MCU.

        a2_relay.png


        Connectors and Cabling 

        Connectors and cables allow your gadget to permanently or temporarily connect to the outside world.  The simplest and cheapest of connections are formed by soldering wires to pads on the PCB and then providing strain relief with a glue compound that connects the jacket of the wire to the PCB, or by pinching the wire jacket in the enclosure as it is closed around the wire.

        Standard connectors are more affordable than custom connectors due to economies of scale.  Whenever custom cables are created, the cost of the non-recurring engineering needs to be factored into the economics of how many cables are going to be ordered.


        Headers are metal pins that stand up from the PCB and allow a connector to be slid down over the pins, forming a temporary connection.  These are used with ribbon cables to form a simple connector and cable solution, or by themselves as a board-to-board connection.

         a2_header.png


        Jumpers are small lengths of wire or metal that “jumper” nearby header pins.  These can be used to temporarily configure a circuit for debug purposes, and are found on many PC motherboards to clear the startup options to a default state, or for prototype cabling purposes.

         a2_jumper.png


        Ribbon cables are formed by ganging many wires together to form a ribbon.  The ribbon cable can provide a temporary or permanent connection between PCB boards and is readily available for ordering in various sizes and configurations, and attach to header pins on the PCB.

        a2_ribbon.png

         

        Spring pin connectors create a connection of a cable to a PCB board without a mating receiving socket.  These types of cables are typically more expensive than standard cables and are generally reserved for factory programming or debug use.  The advantage of these cables is that there is no physical connector required on the PCB, so there is zero cost per board during manufacturing.

        a2_spring_pin.png
        Application-specific connectors
        and cables are available to connect your device to standard interfaces such as USB, HDMI, Ethernet, RCA audio cables, headphones, microphones, and more.  It is often simpler and more cost effective to reuse a pre-existing cable and connector for your project than to create your own custom solution. 

         

        Sensors

        Sensors give your gadget the ability to detect or measure something about the environment that they operate within.  They can be made up of simple unpowered physical sensors or all-in-one digital chips that perform analysis on the simple physical sensors and provide a digital interface to those sensors.  Sensors can be cheap devices to detect a simple change in the environment or accurate, expensive devices that can require calibration procedures.

         

        A passive sensor (i.e. a sensor that doesn’t require a power connection) is a device that is designed to create a measureable change in some electrical property that is brought on by the change in the physical nature of the material.  For example, the application of heat, pressure, light, presence, or motion to a sensor can create a change in voltage, capacitance, piezoelectric, or some other electrical property that can then be measured by an external circuit.

         

        A digital sensor will incorporate the passive sensor but combine that simple sensor with integrated circuits that provide an interface that make the measurement process simpler.  These devices have the ability to offload the computational and time-critical tasks of sensor management so that your MCU can be free to do other things. 

         

        Most of the components of this section do not have a common schematic symbol.  The schematic symbol is normally just a box with a part number above or below the box, and pin names on each pin.  Likewise, the sensors themselves are a mix of different chip packages.  Use the following section as a guide to the terminology that you will need to find more information at the component suppliers web sites.

         

        Voltage sensors can be formed with transistors that are set to trigger at a specific voltage through the use of voltage dividers.  Voltage can also be detected through peripherals on the MCU such as the Analog-to-Digital Converter (ADC) or the Analog Comparator.  Voltage sensors can help your circuit detect proper operating voltage or take action to shut down or signal alarm if the voltage is leaving the safe operating zone.

         

        Current sensors can be formed with a precision resistor of low resistance (under 1 ohm), whereby the voltage before and after the resistor is measured via an ADC or Analog Comparator and the current can then by calculated with the measured voltage drop and Ohm’s law.  This information can be helpful in determining rate of battery consumption, or ensuring that a design does not consume more current than allowed.

         

        Hall Effect sensors provide an analog output that changes proportional to the amount of magnetic flux in the environment.  Two pins provide power and the third pin is the analog voltage output.  Hall effect current sensors can detect the amount of current flowing in a wire since current flow produces a magnetic field.  These sensors can also be used to build a proximity and/or distance detector by measuring the magnetic flux of a magnet embedded in the gadget.

         

        Temperature sensors are available in a wide variety of technologies.  Thermistors are resistors whose material properties are chosen such that the resistance changes reliably over temperature.  Thermostats are switches that close at a specified temperature.  Simple mechanical thermostats are formed with a coil of metal that changes shape with changes in temperature and causes a metal contact to close.

         

        Thermocouples measure temperature by creating voltage at the union of two different types of metals.  This allows a probe to be placed on the end of a long wire and the temperature of the wire to not affect the measurement of the temperature at the tip, where the measurement takes place.

         

        Rotary encoders are used to measure the angle of rotation of a shaft.  They can be based on optical or hall effect sensors.  These are useful in any project that needs to determine the angle of a wheel or lever.

         

        Strain gauges measure the amount of stretch in a material, which can then be used to calculate the tensile load.  The gauges are attached to the material with a high-strength adhesive.  Wires of a known resistance are embedded in the gauge in a particular pattern.  As the strain gauge deforms, the resistance of the wires changes, which can then be correlated to the tensile load applied to the material.

         

        Pressure sensors measure the pressure of a gas or liquid.  There are many different types of pressure sensors that implement a wide range of mechanical solutions to determine the pressure.  For example, a change in a diaphragm which has an internal spring can be measured with a simple potentiometer that changes the resistance of the sensor with spring deflection. 

         

        Microphones are a type of pressure sensor that is used to measure sound pressure waves.

         

        Transducers act like both speakers and microphones for frequencies above the audible range, in the ultrasound frequency range.  Transducers are used in proximity detection and in ultrasonic imaging systems.

         

        Humidity sensors measure the amount of moisture in the air through resistive or capacitive changes in the sensor.  The temperature must also be measured in order to calculate the relative humidity.

         

        Accelerometers measure the amount of acceleration subjected to the sensor.  The acceleration can be due to gravity, making a tilt sensor, or to the effects of movement of the sensor.  Some accelerometers can offload processing of certain events, such as free fall, or the application of acceleration above a specific threshold, so that the MCU does not need to constantly monitor for those kinds of events.  Accelerometers can be ordered for the number of axes that the device measures, or Degrees of Freedom (DOF), as well as the range of acceleration, specified in g’s.

         

        Gyroscopes measure the angular rate of rotation or position in space.  Similar to accelerometers, the gyroscopes have three axes or DOF and can be ordered according to the number of degrees of rotation per second that they can measure.

         

        Magnetometers measure the strength and direction of a magnetic field and are used to measure the compass heading of the device, as long as nearby electric fields are not present to block the Earth’s magnetic field.  Magnetometers have three axes or DOF.

         

        Inertial Measurement Units (IMUs) combine the functions of accelerometers, gyroscopes and magnetometers to give a “9-axis” or 9 DOF sensor that allows a device to more precisely track its position in free space. This is known as sensor fusion.

         

        In the next lesson, we will wrap up our overview of electronic components with a look at actuators, integrated circuits, and power regulation chips.

         

         PREVIOUS | NEXT

      • Silicon Labs Opens Nasdaq

        Lance Looper | 08/236/2016 | 07:22 PM

        We have been celebrating our 20th anniversary all year, and the party continued this morning in Times Square where CEO Tyson Tuttle and other members of the senior leadership team rang the opening bell. 

         

        Since January we've been looking back at some of the products, people, and milestones that have shaped the company. We're proud to have been a part of building a more connected world and look forward to what the next 20 years have in store!

         

         

        We've come a long way since 1996. Our IPO took place just four years after becoming a company and our valuation hit $1.2B. Shares nearly tripled in the following months, enabling us to repay our venture capital investors.

         

         

        It's not all business, though. It looks like CEO Tyson Tuttle and CFO John Hollister carved out enough time for a selfie. 

         

        Screen Shot 2016-08-23 at 6.15.50 PM.png

      • August 2016 Member Spotlight: hollie

        Nari | 08/231/2016 | 11:01 AM

        We are featuring one of the Silicon Labs Community members who is active or new in the community on a monthly basis to help members connect with each other.

         

        Meet our July member of the month: hollie

        0,17,640,640.jpg

         

        Q: Congrats on becoming our featured member of the month! Can you introduce yourself to our community members?

         

        Thanks, I’m honored to be featured! I’m Lieven Hollevoet, located in Belgium. 

         

        I’ve been interested in engineering since childhood. I vividly remember the many devices that I disassembled to get to know what made them tick. Re‐assembly was a challenge and a learning experience too. I’m still sorry about my sisters’ fancy alarm clock that proved a too big challenge for me that time :-).

         

        Then I discovered electronics around my 12’s and I started building kits. That evolved into making my own circuit designs. Of course I studied electronics after high school.

         

        I started my career at the research institute imec working in the wireless system department where we designed power‐efficient ASICs for next- generation high‐speed standards. During that time, we also had cooperation with local SME’s to assist them in bringing new technology into their existing products.

         

        In 2012 an ex‐colleague from imec and me started our own company ‘Quicksand’ where we design low power electronics. Typical examples are devices that need to operate a long time on a single battery charge. We already have a track record of a few challenging projects like a wearable personal communicator for elderly, a smart water valve/meter combination, and various sensor devices.

         

        As part of our quest for low‐power solutions, we have also built up quite some experience with a low‐power wide area communication solution called Sigfox.

         

        Q: How did you know about the Silicon Labs Community?

         

        Since we focus on low‐power applications, the EFM32 series of microcontrollers are our default go‐to devices when we design a new application. I discovered them right before Silicon Labs integrated that family into their product line. I was a user of the ‘Lizard Lounge’ forum that was setup by Energy Micro, so when the forums were transferred I followed them to the Silicon Labs Community.

         

        Q: What features would you like to see added to the community?

         

        Content‐wise all is there, but according to me it would be nice to have subsections on the forum under 32‐bit devices for the different controller families. Now when you search for info sometimes the hits you get are for a different 32‐bit controller family. It would be nice to be able to narrow the searches down to the exact family you’re searching information on.

         

        Q: What advice would you give to someone new to the community?

         

        First of all: I welcome new users! The more users the community has the stronger it is.

         

        Secondly: don’t only use the forum to post questions when you’re running into problems. Give back to the community from time to time by helping others.

         

        Thirdly: when you have a question and you want to post a question, first check for similar posts. When that does not help then be sure to provide a complete description. Give all details required to understand the problem and to be able to recreate it. Give schematics, source code extracts, … The more the better. The people who can be helping you out are only be able to do so when they understand the problem you have.

         

        Q: Thanks for answering the questions. Any final comment?

         

        Keep up the very good work of providing a multi-platform suite of tools for most energy-friendly microcontrollers on the market. Combining the compiler with a way of measuring the power consumption of the application you’re developing is unique in the market and helps us in developing our applications in an efficient way.

         

      • 20 Years of Building a More Connected World

        Lance Looper | 08/231/2016 | 09:31 AM

        Today is Silicon Labs’ 20th anniversary, and part of the celebration has been this blog series looking back at some of the milestones we’ve hit on our way to becoming a leading provider for IoT solutions. I’ve had the unique opportunity to dive into some of these stories and learn more about what went into building the company. Like how founders Nav Sooch, Dave Welland, and Jeff Scott flipped a coin to decide whether or not to strike out on their own. We still have the quarter!

         20th anniversary banner.png

         

        One theme that stood out from all of the stories I heard. More than the technology or innovations or even the changing business landscape, people were at the center of these stories.

         

         

        A More Connected World

        We started the series with a look at what we mean when we talk about ‘a more connected world’ and how the IoT isn’t just about things. It’s shaping society in new ways every day and we’re excited to be part of that evolution.

         

        The First 5 Years

        In the second part of our series, we shared some insight about the earliest days of the company, including our early success with building better DAAs for modems. In the first half-decade we went from start-up to initial public offering on the strength of the DAA and our CMOS RF synthesizer chip.

         

        First banner.jpeg

         

        Then vs. Now

        Do you remember what your phone looked like in 2016? Your clothes? 2016 seems like worlds away from 1996, and in this post we take a look at some of the differences between the world today and what it was like when we started.

         

        Building Community Connections

        Our employees love giving back, and Habitat for Humanity has been a fun way for us to give back as a team. In this blog we shared about our experience rebuilding the home of an Onion Creek resident after hers was destroyed by flooding in 2013.

         

        Habitat.png 

         

        Employee Spotlight

        This year two long-time employees, Jon Ivester and Bill Bock, retired. We took the opportunity to talk to both of them about their time with the company, how the world has changed since those early days, and what they feel the future holds for the IoT.

         

        Spotlight on Innovation

        Of course we wouldn’t be where we are without our customers. In this post we spoke to James Jeffries, the CEO of Mobilogix, about its mission as an end-to-end IoT integrator and how technology has changed over the course of 20 years.

         

        mobilogix banner.png

         

        Bluegiga Acquisition and the IoT

        Last year we acquired Bluegiga Technologies, a privately held company based in Espoo, Finland and one of the world’s fastest growing independent providers of short-range wireless connectivity solutions and software for the IoT. This was a major step toward bringing our vision for a more connected world to life.

         bluegiga banner.png

         

        A Short History of MCUs

        In this installment, we explore how we entered the multibillion-dollar, 8-bit MCU market in 2003 with the acquisition of Cygnal Integrated Products. By the end of 2004, we had more than 70 MCU products that captured, computed and communicated signals in a single system-on-a-chip (SoC). The rest is history.

         Bees and Geckos.jpeg

      • From Concept to Market in Just 3 Weeks: IoT Hero Microtronics Breaks Down Development Barriers

        deirdrewalsh | 08/229/2016 | 12:21 PM

        Banner-microtronics.jpg

        We recently spoke with Gregor Bader, senior embedded software developer and team leader DC-FW, and Martin Buber, co-founder, from Microtronics, an Austrian company that’s been on the cutting-edge of IoT development since 2006. What we find fascinating about these IoT Heroes is that they are essentially serving as a springboard for companies to realize their IoT ambitions. Here’s how the firm helps breathe life into the IoT journey for their customers, democratizing IoT access for the entrepreneurs and innovative companies that will help propel the Internet of Things into the Internet of Everything.

         

        For those totally unfamiliar with you, tell us about your business.
        We started out in 2006, so we have 10 years’ experience in the market. Microtronics was started as a spin-off of INAUT Automation GmbH and later that year we were awarded the Karl Ritter von Ghega innovation prize.

         

        Simply put, we play in the M2M space; that’s our specialty. You bring us your potential product portfolio, and we help you make it smart. We help you meaningfully connect it to the IoT—the actual nuts and bolts of getting your device efficiently collecting and sharing data, talking to whatever or whoever it is suppose to talk to.

         

        It’s our goal to help you turn your idea into a market-ready product, and we can do it in three weeks. It’s not easy, and it takes the right combination of software, hardware, and service. Bringing these elements together in one ecosystem is how we help our customers go from proof-of-concept to market availability.

         

        I like your emphasis on “meaningfully” connecting to the IoT. Can you elaborate?
        Of course. We don’t want our customers to just throw some sensors on any and every product they have, to succumb to this pressure that maybe everything they do has to be smart. We want to help our customers focus on their best and brightest potential entrants into this space, to bring the best of their business thought alive in the IoT, making their participation really relevant in the process. It’s all about creating true value for what really matters—the end-users—and not losing focus on that.

         

        We also like helping our customers be nimble in terms of their overall IT solution for their connected devices. We often see companies that are trying to force their smart devices to fit into existing networks and classic IT infrastructures to their detriment. The IoT requires scalability, and we want to see people deploy solutions that can painlessly scale and show real stability as well.

         

        We’ve been using GSM modules from Silicon Labs since the beginning. And starting about four years ago, we’ve been using the EFM32 Giant Gecko 32-bit MCU and have built our rapidM2M product family on this device. 

         

        RapidM2m_M3_gross.jpg

         

        Connectivity has become critical for staying competitive for many companies, can you walk us through the process you go through with customers?

        Today, improving upon a product usually means adding some level of connectivity. Soon when you see an everyday object, a coffee maker for example, that isn’t connected to the Internet you will wonder why that is.

        With customers, we start with the concept. They bring us an idea and we discuss the business model, either their existing model or potential ways to address the market. This is where we define requirements and get an idea of what to expect. After that, we move to proof-of-concept. This is where the application script is developed and we’ll demo a web app. Finally, we’ll pilot the project by integrating the module and application script into the customer’s product. After this, it’s ready for production.

         

        Can you tell us about some of the applications you’ve been a part of?
        We have several recent projects that demonstrate the value of connectivity in places you might not think about it. One example, Payuca, is best described as Airbnb for parking spaces. Payuca really wanted to develop an app that took the anxiety out of parking. Users can search for a parking space in the area they need and proceed directly there without wasting time circling for an empty space. We built that application with a Bluetooth low energy module, RFID scanner, 3G modem, and, of course, the EFM32 Giant Gecko 32-bit MCU. What’s really nice is that parking garages that are available for the users can be opened over BLE with either iOS or Android when they arrive.

         

        Another project was with a company called PaketButler, and we helped them build a low-power lock system that people can use to secure packages outside their homes, for either sending or receiving goods. It’s powered with a 2G modem, Bluetooth, and Giant Gecko. After authentication via Bluetooth, the lock opens up for the user and they can pick up packages or leave one securely for the recipient.

         

        PaketButler_2.png

         

        We also helped Fieldeye® create a visual condition monitoring system for agriculture that’s really interesting. It lets customers monitor temperature and precipitation of crops in harsh conditions, enabling targeted, efficient use of pesticide and fertilizer. The photos as well as the rainfall and temperature records can be saved and analyzed over time. For this project, we used Giant Gecko with a parallel Linux cluster for image capture, two 13MP cameras, a solar panel, and a 3G modem.

        FieldEye_1.png

         

        And earlier this year we announced a partnership with T-Mobile Austria to launch its “IoT Box” product, which further democratizes the Internet of Things by giving customers the ability to integrate systems, websites, and smartphone apps.

         

        Fears about security are obviously always a huge component of IoT development and discussion, especially for new entrants to the space. How do you educate your customers about security?
        We are very much in the camp that security is not a distinct step, that it’s an ongoing, continuous, layered process. We also advise our customers that if they stack two or three IoT vendors together as their solution—all with different interfaces, updates, etc.—that they could be opening themselves to vulnerabilities in the long term versus having one secured solution where we’re controlling the whole software stack end to end continuously and fluidly.

         

        What market trends have you observed in your company in terms of particular industries making really pertinent strides in IoT right now? Any trends you expect in the future on that topic as well?
        Honestly, we have a very diverse client base. I can’t say there seems to be more innovation right now in any one segment now or in the foreseeable future. There is an incredible amount of exploration going on, so many talented people across all these fields really pushing the envelope and wanting to explore how the IoT can positively impact and advance their space. Creatively, we are living in exciting times.

         

        In your opinion, what does the future of IoT look like?
        We see the millions of device categories becoming part of the IoT. In addition to the proliferation of connected devices, we see miniaturization becoming part of the landscape as well.

         

        martin_gregor.jpg

         

      • Choosing Electronic Parts for Your Project - Part 1

        lynchtron | 08/228/2016 | 11:55 PM

        electronic_parts_header.png

        In the last few sections, we summarized the process to create your own PCB.  This book/blog series attempts to show you how to design, program, build, and test your prototypes, eventually turning those prototypes into production-worthy gadgets.  Every electronic circuit need is different, however, and your solution to your problem will need specific circuits to solve that problem most efficiently and cost effectively. 

         

        So you have an idea for an electronic gadget...great!  The trickiest step in the whole process is figuring out which electronic components, or parts, are needed to make up your circuits.  This is not a step to be taken lightly.  There are a billion ways to solve any problem and seemingly a billion parts out there to help you do it.  First off, you have to find the components that make your solution possible, and then you will likely need to refine the design such that it is economically viable and power efficient.  There are so many parts out there that it is hard for anyone to know all of the possible options.  It takes a lot of research. 

         

        Often, electronics designers stick to what they know and have experience working on from past projects.  This is with good reason; part specifications can be long, confusing, and sometimes inaccurate documents.  Designing with something that you already know can vastly improve the chances of the prototypes working in short order.  However, technology is always moving forward, and new parts can combine functions of other parts or improve cost and performance over past technologies. 

         

        This section aims to give you an overview of the types of parts that are available and teach you the terminology necessary to find the types of parts needed to solve your circuit problem.  Your parts will be identified by a set of specifications that detail exactly what the parts can do, how much power they consume or dissipate, the temperature they can withstand, how they mount to your board or how they are packaged, the type of material makeup, and their size and weight.  This is just for starters.

         

        The best resource at your disposal to learn about the available options are the electronic part distributors such as Mouser, Digikey, Arrow, Avnet, and Newark, but prepare to be overwhelmed with choices!  You can also find harder-to-find or specialized parts on eBay and Alibaba.

         

        This post starts with the basic circuit elements and works up to the more interesting active, smart circuit devices.

         

        Note About Packaging

        The packages of electronics components refer to how the parts mount to the circuit board.  Most parts are either soldered to a Printed Circuit Board (PCB) with a through-hole method or with Surface Mount Technology (SMT).  Within the SMT category, devices can utilize legs, pads, or balls to connect to the PCB.  Some parts can be wired into your circuit through wire terminals or lugs.  Yet other devices can utilize specialized connectors between the device and the circuit board.

        a2_packages.png


        Foundational Electronic Components
         

        The simplest of all components are discrete passive components.  These parts only have a singular purpose, such as offering resistance, capacitance, inductance, or adding a voltage or current control.  Most discrete components only have two or three pins.  Although these are very simple devices in theory, there are still a million choices to be made regarding the construction of each device.  Electronics engineering is a very specific industry, so be prepared for that. 


        Resistors offer electrical resistance to a circuit.  Resistance is measured in ohms, designed as Ω.  Parts are ordered according to the resistance as well as the current capacity of the device.  Resistors are packaged most commonly in either a through-hole or SMT package.  Resistors have no polarity and can be installed in any direction.  Resistor networks are parts that combine multiple resistors together in the same package in order to save space on the board and simplify assembly.

        a2_resistors.png

         

        Potentiometers are variable resistors that have three terminals.  The potentiometer is simply a resistor that has third pin to act as a mechanical “wiper” that allows the resistance between terminals 1 and 2 or 2 and 3 to be varied.  Potentiometers can be used to allow user input into a circuit, for example a volume knob on a stereo.  They can also allow fine tuning of a design during the production process.  Potentiometers are ordered according to the total resistance offered and the degrees of turn, or number of turns that the wiper allows.  Higher accuracy and more turns increases the cost.  Potentiometers have no polarity are packaged in through-hole and SMT packages for production but are commonly implemented with wire lugs.
        a2_potentiometers.png 
         
        Capacitors store electrical charge.  Capacitors have many applications in filtering of frequencies.  They can be used to store charge for a power regulator circuit or to dampen frequency response of a circuit.  Capacitance is measured in Farads designated as F, most commonly in micro, nano or pico Farads, designated as µF, nF, or pF.  Capacitors are packaged most commonly in either through-hole or SMT packages.  Electrolytic capacitors have a polarity and must be installed such that the positive lead is always more positive charge than the negative terminal, or else the capacitor could be destroyed.  Non-electrolytic capacitors have no polarity constraints.  When ordering capacitors, you must specify the type of polarization, the type of dielectric (i.e. ceramic, plastic, paper, etc.) the voltage rating, and the amount of capacitance offered.  There are many different types of capacitors that have many specific uses.  More information on capacitors can be found here.

        a2_capacitor.png

         


        Inductors store electrical energy in a magnetic field.  Like capacitors, inductors are primarily used in filtering of frequencies.  Inductance is measured in Henries, most commonly in micro or nano Henries, designated as µH or nH.  Inductors are packaged most commonly in either through-hole or SMT packages.  Inductors have no polarity constraints.

        a2_inductors.png

         

         Ferrite beads, also known as chokes, offer impedance to a circuit.  Ferrites are primarily used to prevent high-frequency noise from propagating past them and are often found on the end of cables that connect devices together.  They can be ordered in through-hole, SMT or as a wire shield.

        a2_ferrite.png

         

        Transformers are essentially two inductors that are packaged together to transmit alternating current (AC) power from one circuit to another through electromagnetic induction.  They are commonly used to transform an AC voltage from one value to another.  The number of windings in each inductor dictates how the voltage will be transformed.  In this way, they are a simple AC voltage converter, based upon how the transformer is constructed.  Transformers can be packaged in a variety of different packages from SMT all the way up to house-sized buildings for commercial power delivery.

        a2_transformer.png 

        Diodes are devices that either permit or block the flow of current in a circuit, based on the voltage on its terminals.  The current can only flow if the anode terminal is at a higher voltage than the cathode terminal, usually by at least 0.7 volts.  Diodes are like a one-way valve for voltage, and prevents voltage from going the wrong way.  They are used in power conversion from AC to DC and to protect circuits from an out-of-bounds voltage input.  A Zener diode is a special kind of diode that is used as a power regulator.  A Schottky diode has a lower forward voltage drop (in the 0.15 to 0.45V range) and a faster turn-on time.

        a2_diodes.png

         

        Light Emitting Diodes (LEDs) share many of the same properties with normal diodes, covered above, but are primarily used to generate light.

        a2_leds.png

         

        Photo Diodes perform the opposite function of LEDs, whereby they produce electrical current if light is present.  These devices are useful to detect the presence of light.

        a2_photodiodes.png

         

        Transistors are versatile circuit elements that are the most complicated of the passive discretes on this list.  The three-pin devices can be used as voltage or current-dependent switches, or as power amplifiers or regulators, depending on the circuit.  If you have a problem, there is a solution that can be created with transistors, as a microprocessor is at its heart a very large collection of transistors.  There are two general technology types, Bipolar Junction (BJT) and Field Effect (FET.)  These two types of transistors differ in pin terminology.  The BJT transistors have two sub types, known as NPN and PNP which describe the polarity of the component.  The FET transistors have many sub types that pertain to n-channel and p-channel. More information on the types of transistors can be nicely summarized here. Note that the direction of the arrows in the symbol change based on the type of transistor it is describing. 

        a2_transistor.png 

        In the next section, we’ll cover more parts that every project likely needs: switches, connectors and sensors.

         

        PREVIOUS | NEXT

      • Days of Thunderboard Derby

        jwilczek | 08/225/2016 | 03:48 PM

        We’re committed to building a more connected world by enabling the bright minds of today with innovative technology. That mission comes through loud and clear with our new Thunderboard React, a cloud-connected, Bluetooth-enabled, sensor-driven platform that lets customers demo, evaluate, and develop their own projects. And what better way to show off everything this board has to offer than putting it inside a classic pinewood derby car?

         

         

        PumpStudios.JPG

        Pump Studios shows off their winning design at the awards ceremony.

         

        Hottest Design.JPG

        Pump Studios (second from the left) decked out their car and installed a working speaker, winning the award for Hottest Design.

         

        We invited over 200 innovators, tech leaders, and influencers from civic organizations, STEM based non-profits, schools, and tech companies from Central Texas to participate. Four weeks before the event each of them received a Thunderboard React Car Kit for them and their pit crews to modify as desired, with instructions to show up at Austin’s Google Fiber Space to see how they stack up against the area tech community in the Days of Thunderboard Derby.

         

        Car2Go.JPG

        We had some pretty dedicated teams, but Car2Go stole the award with their awesome team spirit.

         

        Team Spirit.JPG

        The winners of the best Team Spirit, Car2Go, poses in costume with their dramatic Thunderboard car.

         

        The teams arrived with souped-up cars and coordinated outfits ready to dominate the races. The Thunderboard derby cars showcased everything from design skills with the use of 3D printed spoilers and LED lights, to chip enhancements that supported propellers and motorized wheels. The teams mingled and trash-talked the competition as they waited for their chance to show off how they had modified the Thunderboard React in their own way.

         

        Fastest Car.JPG

        Bulldog took home the award for fastest car, equipping their car with a motorized fan.

         

        The derby consisted of 12 heats with more than 40 cars. Competition was stiff, but only three teams took home a prize. The three categories of fastest car, hottest design, and most team spirit were voted on by a panel of judges, with winners each awarded $500 to donate to the local STEM non-profit of their choice.

         

        Tyson.JPG

        Tyson Tuttle, our CEO, welcomes the crowd at Google Fiber.

         

        Thunderbaord Derby Group Picture.JPG

        A great night for the Austin tech community.

         

        The IoT is all about taking everyday devices and connecting them to make something more. The Days of Thunderboard Derby showcased the innovation and creativity that can happen when great minds come together and create. Most of all, it showed us all that with all the opportunity and power the IoT holds, it can be just as fun as a good old fashion derby race.