Logging is very important for developing embedded products, especially for connection based wireless products because the use of breakpoints will probably result in dropped connections. Whereas, we can easily address problems by walking through the log. This article will introduce a simple implementation of logging on EFR32 based devices. The key point of this article is to introduce a way to classify the log into different levels, and each level of log has its own identifier.

Introduction

Let’s start with 2 design sketches, which demonstrate outputting the log via RTT and VCOM(UART).

Figure 1. Using RTT

Figure 2. Using VCOM

From the pictures, you can see the different level of logging uses different colors, this article introduces 5 levels of logging as below.

Table 1.Log types and colors

Settings

The symbol LOG_PORT, defined in log.h, can be set to SEGGER_JLINK_VIEWER or PORT_VCOM to determine which terminal the output should be sent to.

• SEGGER_JLINK_VIEWER – the log will be out from J-Link RTT.
• PORT_VCOM
  • If VCOM is enabled, the log will be out from VCOM via USB.
  • If VCOM is disabled, the log will be out from the UART TX pin directly.

The definition of LOG_LEVEL in log.h determines which level of logging should be output to the terminal. As you can see from the table 1, error has the highest level while verbose has the lowest level. For example, If the LOG_LEVEL is defined as information level, then error, warning and information log will be sent to terminal, the debug and verbose log which have lower level than information will not be sent to the terminal. See figure 3, which shows the log as information level without modifying anything from figure 1.

Figure 3. Log with information level

Logging Functions

There are 5 corresponding functions to send the log, the input parameter of these five functions is the same as standard printf();.

• LOGE() – Send ERROR log.
• LOGW() – Send  WARNING log.
• LOGI() – Send INFORMATION log.
• LOGD() – Send DEBUG log.
• LOGV() – Send VERBOSE log.

How to migrate it to your project

Follow below steps to enable this feature in your project and customize it to meet your requirements.

1. Clone/Download the file from https://github.com/KevinFuSilabs/log_module
2. Add #include “log.h” and INIT_LOG(); to the initialization area, just as the attached main.c.
3. Modify the project settings, add ${workspace_loc:/${ProjName}/third_party/RTT}/"${workspace_loc:/${ProjName}/log_system}" to include paths
4. Set the HAL_VCOM_ENABLE symbol in hal-config.h to 1 if needed.

After all the above is done, your project should be able to send the log to the terminal.

Some notes.

• The main.c in the attachment is based on Bluetooth SDK v2.8.1, if you are using other version than it, it might not work if you simply replace it because the structure changes of different SDKs. In this case, you need to modify the code manually as the second half of step 2.
• This log system can be used to any EFR32 devices and it should be possible to use it on EFM32 device directly or with a few changes.

While developing with Silicon Labs Bluetooth SDK, users can use the API – gecko_cmd_le_gap_bt5_set_adv_data() to set the advertisement and scan response data. The data has a standard format, whereas the data passed to above API is uint8array.  This article will focus on adding a middle layer between user application and the BG stack API to set the advertisement payload, which makes the payload more straightforward, visible and easier to understand for users.

For more information about the advertising data, you can go to the Bluetooth KBA Index and see the “Advertising” category.

Schematics and other documentation for radio boards can be accessed easily from Simplicity Studio.

Studio is context sensitive, meaning it will try to show you the relevant content for the hardware that you are working with. You can plug in your kit using USB and Studio will recognize the kit automatically. In that case, the kit details will show up in the Devices window.

Alternatively, you can manually enter the kit / radio board number in the Solutions window. Studio has auto-complete feature that will suggest you list of available options, it is enough to enter just the first part of the board or kit ID (for example, typing BGM111 will show a list of all BGM111 radio boards). This method allows you to access schematics and other documentation for kits even if you don't have the physical kit available. For example, you can check the docs and schematics before even ordering a kit.

Following screenshot shows an example how to locate schematics, assembly drawing etc. for BGM13P radio board (BRD4306A). Note that the item that is selected in the Devices or Solutions tab dynamically changes the content that is shown on the right hand side of the window.

This same method can be used to access other documentation relevant to your target hardware, including:

• application notes
• data sheets
• reference manuals
• quick start guides ...

Introduction

This Knowledge Base Article (KBA) aims to act as a “master” KBA which keeps a curated index of all the Bluetooth related KBAs divided into logical categories for an easier and more convenient look-up. It may also include non-KBA content which is relevant for designing your Bluetooth application (e.g. app notes or web pages).

If you are just getting started with Silicon Labs Bluetooth solutions then your starting point should be QSG139: Getting Started with Bluetooth® Software Development. At the end of that document you are presented with the flowchart below which shows what documents should be read and in which order. Additionally you can check out our Bluetooth Training page for more training material.

Knowledge Base Articles List

The content listed below is grouped together into categories to make it easier for you to find what you are looking for. Want to know more about security, or looking for a peripheral example, then head down to the right section and see what KBAs or other relevant content has been created under those topics.

Each category has an associated index number and each individual KBA has its own index number within the category. The KBA's are prefixed with KBA_BT_AABB where AA is the category index and BB is the KBA index within that category. The category index numbers are as follows:

• [01] Bluetooth - General
• [02] Bluetooth - Advertising
• [03] Bluetooth - Stack features
• [04] Bluetooth - Performance
• [05] Bluetooth - Bluetooth Mesh
• [06] Bootloading - General
• [07] Bootloading - UART DFU
• [08] Bootloading - OTA DFU
• [09] Application Examples
• [10] Peripheral Examples
• [11] Security
• [12] Tools
• [13] Hardware
• [14] Migration
• [15] Mobile
• [16] NCP

Note: Do you want to get automatic notifications when new content is added to the list? Just click the Follow button in upper right corner to subscribe to email notifications. We will make comments when new content is created to trigger those notifications.

[01] Bluetooth General

• KBA_BT_0101: Selecting Your Blue Gecko SoC/Module
• KBA_BT_0102: BLE Basics (master/slave, GATT client/server, data RX/TX)
• KBA_BT_0103: Understanding the Bluetooth Connection Process
• KBA_BT_0104: Acknowledged vs Unacknowledged GATT operations 
• KBA_BT_0105: Bluetooth 5 Features 
• KBA_BT_0106: Bluetooth SIG Resources 
• KBA_BT_0107: Bluetooth Stack Operations Flowcharts

[02] Bluetooth - Advertising

• KBA_BT_0201: Bluetooth advertising data basics 
• KBA_BT_0202: Bluetooth advertising using manufacturer specific data 
• KBA_BT_0203: Providing Extra Data by Scan Response 
• KBA_BT_0204: Using scan request reporting
• KBA_BT_0205: Advertisement Constructor 
• KBA_BT_0206: Extended Advertising Example 
• KBA_BT_0207: Periodic Advertising
• KBA_BT_0208: Chained Advertisements

[03] Bluetooth - Stack features

• KBA_BT_0301: LE Coded PHY on EFR32xG13
• KBA_BT_0302: Advertising and Scanning with LE Coded PHY 
• KBA_BT_0304: Different characteristic value types 
• KBA_BT_0305: Handling GPIO Interrupts using External Signals 
• KBA_BT_0306: Using the lazy soft timer
• KBA_BT_0307: Enabling TX/RX activity indicator pins in BLE SDK 2.4.0 and later 
• KBA_BT_0308: Polymorphic GATT 
• KBA_BT_0309: How to save float values (or any arbitrary data) in PS keys
• KBA_BT_0310: Changes to the le_gap class of API functions
• KBA_BT_0311: Whitelisting
• KBA_BT_0312: Service Change Indications 
• KBA_BT_0313: GATT Caching

[04] Bluetooth - Performance

• KBA_BT_0401: Optimizing Current Consumption in Bluetooth Low Energy Devices 
• KBA_BT_0402: EM3 and EM4S for non-connectable advertising 
• KBA_BT_0403: Using Energy Modes with Bluetooth Stack 
• KBA_BT_0404: Throughput with Bluetooth Low Energy technology
• KBA_BT_0405: Bluetooth Tx power settings
• KBA_BT_0406: Adaptive Frequency Hopping
• KBA_BT_0407: Bluetooth Radio Task Priorities
• KBA_BT_0408: Current consumption during advertising with different Tx power setting
• KBA_BT_0409: Using the PLFRCO as low-frequency clock source
• KBA_BT_0410: TX power limitations for regulatory compliance (ETSI, FCC)

[05] Bluetooth - Bluetooth Mesh

• KBA_BT_0501: BT Mesh embedded provisioner example 
• KBA_BT_0502: Bluetooth Mesh Vendor Specific Model Example 
• KBA_BT_0503: Advertising Sets Used by the Bluetooth Mesh Stack
• KBA_BT_0504: Adding custom advertising to the Bluetooth mesh examples
• KBA_BT_0505: Bluetooth Mesh Training resources
• KBA_BT_0506: Minimalistic OnOff client for testing Bluetooth Mesh on custom board
• KBA_BT_0507: Bluetooth Mesh Host Switch Example
• KBA_BT_0508: Scanning BLE beacons in Bluetooth Mesh mode 
• KBA_BT_0509: Bluetooth Mesh Host Provisioner
• KBA_BT_0510: Blacklisting Nodes From Bluetooth Mesh Network
• KBA_BT_0512: Bluetooth Mesh Proxy Client Example
• KBA_BT_0513: IV Update & Recovery Procedure and Sequence Number Storing Strategy

[06] Bootloading - General

• KBA_BT_0601: Why Doesn't My Sample Application Run?
• KBA_BT_0602: Bootloader changes in BLE SDK
• KBA_BT_0603: Adding Gecko Bootloader to Bluetooth projects
• KBA_BT_0604: Switching between firmware images using Internal Storage Bootloader
• KBA_BT_0605: Upgrading Gecko Bootloader
• KBA_BT_0606: Upgrading Gecko Bootloader with Slot address change
• KBA_BT_0607: Adding metadata to GBL files 
• KBA_BT_0608: Factory programmed firmware of Bluetooth devices

[07] Bootloading - UART DFU

• KBA_BT_0701: Upgrading from factory firmware (v2.0.0) and from Bluetooth SDK v2.1.x with UART DFU type legacy bootloader
• KBA_BT_0702: UART DFU - Upgrading BGM111 by EFM32PG example 

[08] Bootloading - OTA DFU

• KBA_BT_0801: Using Blue Gecko app OTA
• KBA_BT_0802: Uploading images to internal/external flash using OTA DFU 
• KBA_BT_0803: Bluetooth OTA updates using customized advertising data
• KBA_BT_0804: Secure OTA DFU
• KBA_BT_0805: Setting Bluetooth Address as device name in OTA 
• KBA_BT_0806: Using BLED112 to do Over-the-Air update of BGMxxx 
• KBA_BT_0807: Implementing OTA firmware update in the user application
• KBA_BT_0808: OTA options for NCP-based designs 

[09] Application Examples

• KBA_BT_0901: Bluetooth SoC-Empty example
• KBA_BT_0902: How to use Voice over Bluetooth Low Energy example for Thunderboard Sense
• KBA_BT_0903: SPP-over-BLE example 
• KBA_BT_0904: Creating an Eddystone-URL Beacon 
• KBA_BT_0905: SPP client example using BLED112 dongle 
• KBA_BT_0906: Multi-Slave Multi-Master Dual-Topology example 
• KBA_BT_0907: Parallel handling of multiple slaves with Bluetooth stack 
• KBA_BT_0908: Using RTCC as Timer or Calendar while running BLE stack 
• KBA_BT_0909: Scheduling application tasks while running BLE stack
• KBA_BT_0910: Using the UD flash in the Bluetooth C SDK 
• KBA_BT_0911: Midi over BLE 
• KBA_BT_0912: Control LEDs on a Wireless Starter Kit from a Mobile App 
• KBA_BT_0913: BLE Central and GATT client example - working with an Android app 
• KBA_BT_0914: ANCS 
• KBA_BT_0915: Throughput Tester Example 
• KBA_BT_0916: Working with Long Characteristic Values 
• KBA_BT_0917: Implementing wireless direct test mode (DTM) 
• KBA_BT_0919: Using EM3 or EM4 energy mode in a Bluetooth beacon app 
• KBA_BT_0920: Bluetooth Device Tracking with Tile
• KBA_BT_0921: Using Mbedtls with BLE 

[10] Peripheral Examples

• KBA_BT_1001: Using the LEUART 
• KBA_BT_1002: Using Low Energy Timers 
• KBA_BT_1003: Using accelerometer found in the WSTK expansion board 
• KBA_BT_1004: Hardware Timers with EFR32xG1x 
• KBA_BT_1005: Reporting Battery Voltage over BLE 
• KBA_BT_1006: Thermometer example with EFR32 internal temperature sensor 
• KBA_BT_1007: Enable LCD screen on WSTK 
• KBA_BT_1008: Watchdog on BGM111 (and other Blue Gecko modules / boards) 
• KBA_BT_1009: Waking from Deep Sleep Using RF Sense 
• KBA_BT_1010: Push buttons and interrupts in a Bluetooth project 
• KBA_BT_1011: How can I extend the Bluetooth examples with UART functionality? 
• KBA_BT_1012: Adding Watchdog in NCP Mode

Additional Resources

• MCU Peripheral Examples on GitHub (also includes EFR32)

[11] Security

• KBA_BT_1101: Using Bluetooth security features in Silicon Labs Bluetooth SDK
• KBA_BT_1102: Pairing Processes
• KBA_BT_1103: Application Layer Security 
• KBA_BT_1104: The New Bond Replacement Algorithm
• KBA_BT_1105: How to handle missing bonding keys 
• KBA_BT_1106: OOB introduction and example 
• KBA_BT_1107: Secure connection with serial communication between two BGM modules 
• KBA_BT_1108: Authenticating Bluetooth Devices with no User Interface 

[12] Tools

• KBA_BT_1201: Condensed Bluetooth SDK revision history (2.0.0 and later)
• KBA_BT_1202: Building C++ BLE projects
• KBA_BT_1203: Creating projects for EFR32BG on a custom board
• KBA_BT_1204: How to flash BGM11x or EFR32BG from command line?
• KBA_BT_1205: Programming an external BGM111 using the WSTK
• KBA_BT_1206: Log System
• KBA_BT_1207: Event and Error Checking 
• KBA_BT_1208: Using virtual COM port (VCOM)
• KBA_BT_1209: Debugging BGTool not being able to communicate with NCP target.
• KBA_BT_1210: Connect Custom board to Simplicity Studio using JTAG/SWD.

Additional Resources

• Simplicity Studio now Treats Bluetooth Modules as Parts

[13] Hardware

• KBA_BT_1301: How to find schematics and other documentation for radio boards?
• KBA_BT_1302: Supplying EFR32 PAVDD from 3.3V
• KBA_BT_1303: Enabling LNA on MGM12P for Bluetooth usage
• KBA_BT_1304: Antenna tuning for BGM12x (coin-cell usage example)
• KBA_BT_1305: Quartz Crystals, MEMS Oscillators, and Phase Noise for BLE Applications
• KBA_BT_1306: TX Power Levels 
• KBA_BT_1307: What is a STEP file and how to obtain a STEP file for Silicon Labs IOT products?
• KBA_BT_1308: Saving CTUNE value as manufacturing token
• KBA_BT_1309: Design and Assembly guidelines when using xGM parts based System in Package (SiP)

Additional Resources

• Debugging and Programming Interfaces for Custom Designs
• Production Programming Options for Silicon Labs Devices
• RF Range Calculator
• Driving FEMs (and PAs and LNAs) on EFR32

[14] Migration

• KBA_BT_1401: Updating NCP projects to SDK 2.4.x
• KBA_BT_1402: Bluetooth Smart SDK Migration Guide From V2.0.1 to V2.1.x
• KBA_BT_1403: Migrating Simplicity Studio projects from Bluetooth SDK 2.1.1 to 2.3.1
• KBA_BT_1404: Migrating Simplicity Studio projects from Bluetooth SDK 2.3.x to 2.4.x
• KBA_BT_1405: Migration guide to Bluetooth SDK 2.7.x

[15] Mobile

• KBA_BT_1501: BLE devices on iOS Bluetooth Settings page
• KBA_BT_1502: Evaluating SPP-over-BLE example using BLE1xx cable replacement app 
• KBA_BT_1503: iOS 9.1 with respect to Bluetooth LE
• KBA_BT_1504: Mobile Devices used for Interoperability Testing
• KBA_BT_1505: Selecting suitable connection parameters for iOS 
• KBA_BT_1506: How to find the Bluetooth 5 feature status of a listed device such as a smartphone

[16] NCP

• KBA_BT_1602: NCP Host Implementation and Example 
• KBA_BT_1603: Local Event Handling on Bluetooth NCP