STM32MP157D-dk1 usb to serial adapter

[michelman]

Hi,

For the past two days I have been trying to get a usb to serial adapter to work on this board, using both the starter package or buildroot. Whatever I do, it only shows up as new full-speed USB device number XX using ehci-platform. Is there something that I am overlooking?

lsusb shows the device as:

Bus 001 Device 010: ID 0403:6001 Future Technology Devices International, Ltd FT232 Serial (UART) IC

It is a very basic adapter, US232R from FTDI.

Thanks in advance!

[Kevin HUBER · Accepted solution]

Hello @michelman ,

By default USB to Serial is not enabled in the linux kernel of the Starter Package.

If you want to use a FTDI cable to have USB-A on the 157D-DK1 board and the serial part on another board, you have to use the developer package.

You have to follow the Getting Started "Develop on Arm® Cortex®-A7": https://wiki.st.com/stm32mpu/wiki/Getting_started/STM32MP1_boards/STM32MP157x-DK2/Develop_on_Arm%C2%AE_Cortex%C2%AE-A7

Install the SDK and get the developer package. Once you have the developer package on your machine, you can follow this wiki page that explains how to modify the linux configuration when using the developer package:

https://wiki.st.com/stm32mpu/wiki/Menuconfig_or_how_to_configure_kernel#Menuconfig_and_Developer_Package

and enable:

CONFIG_USB_SERIAL=y
# CONFIG_USB_SERIAL_CONSOLE is not set
CONFIG_USB_SERIAL_GENERIC=y
CONFIG_USB_SERIAL_SIMPLE=m
CONFIG_USB_SERIAL_FTDI_SIO=m

With these CONFIG enabled and once you have re-build your linux, you should be able to use your FTDI cable.

You should see these kind of traces in your Linux Boot Log:

[   22.614405] usbserial: USB Serial support registered for FTDI USB Serial Device
[   22.620589] ftdi_sio 2-1.2:1.0: FTDI USB Serial Device converter detected
[   22.669315] usb 2-1.2: FTDI USB Serial Device converter now attached to ttyUSB0

Hope it helps,

Best Regards,

Kevin

[michelman]

Hi Kevin,

Thank you for the explanation!

Is there a similar option also in buildroot? I can not get yocto to work properly.

Thank you!

best regards,

Michel