Silicon Labs xG24 Dev Kit

The xG24 Dev Kit is a compact, feature-packed development platform. The development platform supports up to +10dBm output power and includes support for the 20-bit ADC as well as other key features such as the xG24’s AI/ML hardware accelerator. You can find more information on the Silicon Labs xG24 Dev Kit at https://www.silabs.com/development-tools/wireless/efr32xg24-dev-kit

This guide will go over how to set up the Silicon Labs xG24 Dev Kit firmware for data collection or recognition. Once your device is configured, you can find a tutorial on how to use the SensiML Toolkit software in the SensiML Getting Started Tutorial.

Example Data Collection Firmware

In order to use the xG24 board for data collection it must be flashed with data collection firmware. We provide example firmware for using either the IMU (Accelerometer/Gyroscope) or Audio (Microphone) sensors below. We will go over how to build the firmware in Simplicity Studio in the next sections.

Silicon Labs xG24 Dev Kit Data Collection Firmware

Sensors	Protocol	Pre-Built Hex Download	Source Code
Accelerometer/Gyroscope (102 Hz)	Simple Stream V1.0 (Serial)	SensiML_xG24_IMU_Capture_Serial_102Hz.zip	SensiML_xG24_IMU_Data_Collection
Microphone (16000 Hz)	Simple Stream V1.0 (Serial)	SensiML_xG24_Microphone_Capture.zip	SensiML_xG24_Microphone_Data_Collection

Example Recognition Firmware

In order to use the xG24 board in recognition mode it must be flashed with recognition firmware. We provide example firmware source code for using either the IMU (Accelerometer/Gyroscope) or Audio (Microphone) sensors below. We will go over how to include your Model/Knowledge Pack in your firmware in the Flashing Knowledge Pack/Recognition Firmware section.

Silicon Labs xG24 Dev Kit Recognition Firmware

Sensors	Source Code
Accelerometer/Gyroscope (102 Hz)	SensiML_xG24_IMU_Recognition
Microphone (16000 Hz)	SensiML_xG24_Microphone_Recognition

Initial Setup For Building Firmware

Firmware in this guide is flashed and compiled using Silicon Labs Simplicity Studio 5.

1. Install Simplicity Studio 5 at https://www.silabs.com/developers/simplicity-studio

Before building or flashing the firmware, verify that the xG24 adapter firmware is up to date.

2. Open the Launcher tab in Simplicity Studio and check the status of the Adapter FW under General Information. The status should be Latest, if the status is Update then click the update link to download the latest version for the adapter firmware.

3. The example firmware in this guide uses a serial port connection. A debug VCOM port needs to be set up to use a serial connection. In the Debug Adapters window, Right + Click on the xG24 Dev Kit and select Launch Console… from the drop-down menu.

4. In the Console window select the Admin tab and type serial vcom config speed 921600 into the terminal input window and press Enter.

Your board is now ready for serial connections.

Building Firmware From a Pre-Built Hex File

1. Download and unzip the pre-built hex file from the Example Data Collection Firmware section above.

2. Select the Flash Programmer button from the toolbar in Simplicity Studio.

3. Click Browse to select the hex file you wish to flash and click Program

Flashing can also be done through running the debugger. The debugger will first flash your application and allow for breakpoints to be set. The application will remain in flash until another program replaces it.

Building Firmware From Source Code

1. Download or clone the source code from the Example Firmware sections above.

2. Select File -> Import in Simplicity Studio.

3. Navigate to the SimplicityStudio folder from the and select the .SLS file for the project.

4. Click Finish and Simplicity Studio will set up your workspace for building from source code.

5. Build the source code by clicking the Build button

6. (Optional) You can debug the source code with breakpoints by clicking the Debug button. You may need to set up a bootloader before you can debug.

Adding New Sensors to the Data Studio

The default firmware code for the xG24 Dev Kit IMU and Audio sensors. You can add additional sensors to your board and use them for data collection in the Data Studio by modifying the device firmware code in the Simple Streaming Interface.

For more details on implementing the Simple Streaming specification in your firmware see the Simple Streaming Interface Documentation.

Changing IMU Frequency/Sample Rate for Data Collection

The frequency/sample rate that IMU data collection firmware outputs is set at compile-time when you build from source code.

1. Open the file app_sensor_imu.h.

2. Update #define ACCEL_GYRO_DEFAULT_ODR to set the frequency.

3. Re-build the device firmware.

Flashing Knowledge Pack/Recognition Firmware

1. Download a Knowledge Pack Library from the Analytics Studio.

The Silicon Labs xG24 Dev Kit also includes the Matrix Vector Processor for accelerating Neural Network Ops. Select the Hardware Accelerator to take advantage of the processor.

2. Unzip the Knowledge Pack files.

3. Follow the instructions for Building Firmware From Source Code above to import one of the Example Recognition Firmware projects into Simplicity Studio. This will create either a sensiml_recogition_motion or sensiml_recogition_audio workspace depending on the project you selected.

4. Replace the knowledgepack folder inside your workspace with the knowledgepack folder you extracted from the download and re-build the firmware.

   

Viewing Knowledge Pack Recognition Results

When a Knowledge Pack is flashed on the board, the classification results can be viewed by connecting to the virtual COM port in a terminal application. Follow the steps below for viewing the recognition results:

1. Open a terminal emulator (such as Tera Term)

2. Set your serial speed to 921600

3. Create a new connection to your xG24 Dev Kit COM port

You will now see classification results printed in the terminal