ST B-L475E-IOT01A

The ST IoT Discovery Kit (also known as the B-L475E-IOT01A) is a development board with a Cortex-M4 microcontroller, MEMS motion sensors, a microphone and WiFi - and it's fully supported by Edge Impulse. You'll be able to sample raw data, build models, and deploy trained machine learning models directly from the studio. It's available for around 50 USD from a variety of distributors including Digikey.

The Edge Impulse firmware for this development board is open source and hosted on GitHub: edgeimpulse/firmware-st-b-l475e-iot01a.

Installing dependencies

To set this device up in Edge Impulse, you will need to install the following software:

1. Edge Impulse CLI).

2. On Windows:

   • ST Link - drivers for the development board. Run dpinst_amd64 on 64-bits Windows, or dpinst_x86 on 32-bits Windows.

3. On Linux:

   • GNU Screen: install for example via sudo apt install screen.

Connecting to Edge Impulse

With all the software in place it's time to connect the development board to Edge Impulse.

1. Connect the development board to your computer

Use a micro-USB cable to connect the development board to your computer. There are two USB ports on the development board, use the one the furthest from the buttons.

2. Update the firmware

The development board does not come with the right firmware yet. To update the firmware:

1. The development board is mounted as a USB mass-storage device (like a USB flash drive), with the name DIS_L4IOT. Make sure you can see this drive.

2. Download the latest Edge Impulse firmware.

3. Drag the DISCO-L475VG-IOT01A.bin file to the DIS_L4IOT drive.

4. Wait until the LED stops flashing red and green.

3. Setting keys and WiFi credentials

From a command prompt or terminal, run:

edge-impulse-daemon

This will start a wizard which will ask you to log in, choose an Edge Impulse project, and set up your WiFi network. If you want to switch projects run the command with --clean.

Alternatively, recent versions of Google Chrome and Microsoft Edge can collect data directly from your development board, without the need for the Edge Impulse CLI. See this blog post for more information.

4. Verifying that the device is connected

That's all! Your device is now connected to Edge Impulse. To verify this, go to your Edge Impulse project, and click Devices. The device will be listed here.

Next steps: building a machine learning model

With everything set up you can now build your first machine learning model with these tutorials:

• Building a continuous motion recognition system.

• Recognizing sounds from audio.

• Responding to your voice.

Looking to connect different sensors? The Data forwarder lets you easily send data from any sensor into Edge Impulse.

Troubleshooting

Unable to set up WiFi with ST B-L475E-IOT01A development board

If you experience the following error when attempting to connect to a WiFi network:

? WiFi is not connected, do you want to set up a WiFi network now? Yes
Scanning WiFi networks...Error while setting up device Timeout

You have hit a known issue with the firmware for this development board's WiFi module that results in a timeout during network scanning if there are more than 20 WiFi access points detected. If you are experiencing this issue, you can work around it by attempting to reduce the number of access points within range of the device, or by skipping WiFi configuration.

My device is not responding, and nothing happens when I attempt to update the firmware

If the LED does not flash red and green when you copy the .bin file to the device and instead is a solid red color, and you are unable to connect the device with Edge Impulse, there may be an issue with your device's native firmware.

To restore functionality, use the following tool from ST to update your board to the latest version:

• ST-LINK, ST-LINK/V2, ST-LINK/V2-1, STLINK-V3 boards firmware upgrade

I don't see the DIS_L4IOT drive, or cannot connect over serial to the board (Linux)

You might need to set up udev rules on Linux before being able to talk to the device. Create a file named /etc/udev/rules.d/50-stlink.rules and add the following content:

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="3748", MODE:="0666"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", MODE:="0666"

Then unplug the development board and plug it back in.