I am using SI7051, that is Si70 family. I want to know this temp. IC (SI7051) can compensate the humidity effect by the environment?

From the doc. of  "AN607: Si70xx Humidity and Temperature Sensor Designer’s Guide" - "The Si70xx family uses state-of-the-art sensing technologies to create precise monolithic humidity and temperature. Can it also apply on SI7051?

sensors".

Hi, we use the Si7051 on a few products and have been for the last 2-3 years.  A recent build of 30 units resulted in 6 of them with Si7051's not working.  Reflowing the parts does not fix the problem and debugging them showed there is no response from the sensors over I2C.  The Si7051 sensors were replaced and the replacements worked correctly.

We are trying to identify if the sensors broke at our CM or if they are factory defects.  And in either case, how we can avoid future failures.  Are there any known problems with these parts?  Do sensors get individually tested at Silicon Labs?  Can you provide any advice for future builds?

Thanks for any help, and let me know if I can provide more information.

Steve

I'm using the SI7021-A20 sensor for relative humidity readings in a closed and dry container.
The container has desiccant in it, so the humidity readings are very low: around 1%, but also 0%.

When the temperature is cycled from +20°C to +80°C to -40°C to +20°C we see clipping in the RH value when the temperature goes below 0°C.

This happens for all Si7021 chips we use. Please see attached a plot for temperature and relative humidity reading.
Note: the temperature reading is not from the Si7021 chip, we use a different chip for that. I can provide you with the Si7021 temperature data next Thursday.

As can be found in the datasheet on page 21 section 5.1.1. Measuring Relative Humidity:

We incorporate this formula in reading the RH from the sensor.
We added the following logic;
1) When the RH_Code is below 3146 we set %RH to 0 and
2) When the RH_Code is above 55574 we set %RH to 100

Below a plot with the temperature and the relative humidity versus time.

I also read the post on:
https://www.silabs.com/community/sensors/forum.topic.html/si7020_humidity_da-N786
Which redirects to support system case 00098157, but I cannot find that on your website...

Hi, 

i am doing IOT Based Smart parking Application. Please Suggest me which proximity sensor will be good for Car parking application. it should be work with  low power ,indoor and outdoor parking lot. 

hi

1) I want to read the data from Si7005 (USB-DONGLE) directly in to the LabVIEW rather by using the manufacturer provided software.

I am currently using Si7005 (USB-DONGLE) (https://www.silabs.com/documents/public/user-guides/Si7005USB-DONGLE.pdf ) to record Humidity/temperature using the an NI based software provided by the manufacturer.

I am using LabVIEW 2014 SP 1 32 bit. Kindly help me out to read the data directly in to the LabVIEW, please.

2) Please let me know the formula used by the software to convert the reading in to RH and temperature ?

3) How can the relative humidity or water-content in other gas (such as helium) can be measured using this sensor? Is their any way, please ?

Yours sincerely,

Syed

Hi everyone, i'm getting started with Si117xG2 - KIT. I'm downloaded the example project in here: https://www.silabs.com/documents/public/example-code/EFR32MG_Si117x_Static_HRM_SpO2_BLE_Example.zip.

When i build the project with Simplicity Studio, the error show can't find the "native_gecko.h"

I tried to find this error on the internet but it still didn't solve the problem and i tried to find the "native_gecko.h" file on my computer, the result is nothing.

I'm using the MCU 5.7.0.0 SDK with GNU ARM 7.2.1 toolchains. Someone please help me fix this.

Thanks you.

Greetings all,

I am planning to use SI113 for the purpose of measuring the UV Index instantaneously on a wearable device. For the same, I have the following questions

1. How is the calibration done? Is possible to get the K and M values and use it in all cases? 
2. How necessary is a Teflon diffuser? What would happen without it?
3. What are the effects of a mineral glass on the sensor accuracy? 
4. Do you get raw data for the sensor, which includes the details of UVA and UVB? 
5. How do you calibrate the sensor for manufacturing? Is it required to do for each part? How practical is it?
6. For prototype testing, where can we do the calibration as we don't have access to those instruments, is there a facility for the same?

Hi,

I have two questions on the "Si1143-A11-GMR Proximity/Ambient Light Sensor IC with I2C Interface"

1) Can you tell me whether the external layer of the top and side of the package is biocompatible?
If yes, do you have some document/statement to proof this?

2) The height is of importance in our design and I notice that the tolerance on it is quite high 0.65 ± 0.10. Is there any way this can be reduced? Or maybe could you give me some distribution / typical values?

Thanks in advance for your support!

Dennis

Can anyone give me more specific documents about Si117x HRM algorithm?

It's better about the detail of Si117x HRM algorith.

I need it so much.

Thanks.

si1153用做接近检测，工作在自动工作模式，设置门限值，但是测量结果，没有超过门限值，也会产生中断。我想实现在自动工作模式，只有测量结果超过门限值才会产生中断，但是参数不管如何设置都不行，请问有什么办法呢？

I was just playing around with the si7057 and wrote functions for reading electronic ID and Temperature and also wanted to check the returned CRCs. At first I was quite confused, because whatever I tried, I never got the correct crc calculated. In the datasheet an initial value of 0xfc is given.

Then I tried different initial values and found out, that for EID a initial value of 0x00 must be used to get the correct CRC.

  uint8_t rxBuf[8];
  uint8_t crcCalc[6] = { 0 };
  uint8_t crcRead[6] = { 0 };

  // SNA
  SI705Y_Cmd(SI705Y_READ_ID1, 2, rxBuf, 8);

  crcRead[0] = rxBuf[1];
  crcRead[1] = rxBuf[3];
  crcRead[2] = rxBuf[5];
  crcRead[3] = rxBuf[7];

  crcCalc[0] = Crc8_add(rxBuf[0], crcCalc[0]);
  crcCalc[1] = Crc8_add(rxBuf[2], crcCalc[0]);
  crcCalc[2] = Crc8_add(rxBuf[4], crcCalc[1]);
  crcCalc[3] = Crc8_add(rxBuf[6], crcCalc[2]);

  // SNB
  SI705Y_Cmd(SI705Y_READ_ID2, 2, rxBuf, 6);

  crcRead[4] = rxBuf[2];
  crcRead[5] = rxBuf[5];

  crcCalc[4] = Crc8(rxBuf + 0, 2, crcCalc[4]);
  crcCalc[5] = Crc8(rxBuf + 3, 2, crcCalc[4]);

But when I want to read the temperautre and have the crc checked, I need to use a initial value of 0xff.

  uint8_t rxBuf[3];
  uint8_t crcRead;
  uint8_t crcCalc;

  SI705Y_Cmd(0, 0, rxBuf, 3);
  crcRead = rxBuf[2];
  crcCalc = Crc8(rxBuf, 2, 0xff);

/**
 * add a single byte to crc calculation.
 *
 * @param data byte to add to crc calc.
 * @param crc previous crc value
 * @return calculated crc value
 */
static uint8_t Crc8_add(uint8_t data, uint8_t crc)
{
  crc ^= data;
  for (int8_t j = 8u; j > 0u; j--)
  {
    if (crc & 0x80u)
      crc = (crc << 1u) ^ 0x131u;
    else
      crc = (crc << 1u);
  }
  return crc;
}

/**
 * Calculate CRC of temperature sensor data.
 * According to si7057, the initial value has to be set to
 * 0xfc.
 * Although, to get a correct crc calculation for measurements,
 * the initial has to be set to 0xff.
 * For ElectronicID reads, the initial has to be 0x00.
 *
 * @param data bytes to calculate crc over
 * @param length amount of bytes in data buffer
 * @param crc initial value for crc
 * @return calculated crc value
 */
static uint8_t Crc8(uint8_t *data, uint8_t length, uint8_t crc)
{
  uint8_t i;

  for (i = 0; i < length; i++)
    crc = Crc8_add(data[i], crc);

  return crc;
}

I hope, this will help someone.

How to use TWI xfer of TXRX?

Thanks!

Hi,now I'am use 0x70,but it can't read or write to si1175 heart rate sensor.

So,can anyone tell me the i2c address?

Thanks.