This note explains how to set up the STM32MP1 SOM Starter Kit hardware.

As shipped by Emcraft, the kit includes the following hardware components:

1. STM32MP1 SOM module;
2. Development baseboard (SOM-BSB);
3. LCD add-on board with LCD panel (4.3" 480x272 LCD with capacitive touchscreen);
4. Mini-USB Y-cable for USB-based power and serial console.

The Starter Kit provides the following hardware components and interfaces:

To power the kit up, simply connect it to a PC / notebook by plugging a mini-USB cable into the P3 mini-USB connector on the SOM-BSB baseboard. As soon as the connection to the PC has been made, the LED DS1 should lit up, indicating that the board is up and running.

Please note that although for most use case scenarios the power provided by the mini-USB Y-cable (1A) is sufficient to run the kit, theoretically for some very extensive use case scenarios additional power may be required. For such use case scenarios, please apply the wall power to the kit by plugging a power cable (not included in the kit) into the dedicated power connector on the development baseboard.

On the PC host side, the U-Boot/Linux console is available via the P3 dual port UART/USB connector. The software installed on the STM32MP1 SOM configures the serial console for a 115.2 Kbs terminal.

On some Linux distributions, connecting to the dual port UART/USB device causes the Modem Manager package to try opening the TTY device and sending modem commands to it, thus occupying the port. To avoid this effect, the ModemManager package must be disabled on the host with the following command:

$ sudo mv /usr/share/dbus-1/system-services/org.freedesktop.ModemManager.service
/usr/share/dbus-1/system-services/org.freedesktop.ModemManager.service.disabled

On the Linux host, the dmesg command can be used to figure out the TTY devices corresponding to the two serial consoles:

$ dmesg | tail
[495846.154337] cp210x 1-5.1.5:1.0: cp210x converter detected
[495846.216898] usb 1-5.1.5: reset full-speed USB device number 8 using ehci-pci
[495846.292179] usb 1-5.1.5: cp210x converter now attached to ttyUSB0
[495846.292643] usb 1-5.1.5: cp210x converter now attached to ttyUSB1

The U-Boot/Linux serial console is available on the second USB TTY device. For example:

$ picocom –l /dev/ttyUSB1 –b 115200

To get access to the serial console of the STM32MP1 from a Windows host, install the device driver for the CP2105 USB-UART chip.

To provide network connectivity to the board, connect it into your LAN by plugging a standard Ethernet cable into the lower slot of the dual-port Ethernet connector.

By default, the STM32MP1 SOM is configured to boot Linux from the on-module eMMC device in autoboot mode. After you have applied the power to the kit, you can monitor the Linux boot-up sequence on the serial console. After a while, the Linux startup scripts will bring the Weston compositor graphical interface up on the LCD. Specifically, you should see the following on the display:

Touch the graphical button in the upper left corner to start a new xterm window. For instance: