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AZAMA
AZAMA
Associate
October 30, 2019
Question

USART3 on STM32MP157c-dk2 configuration problem

  • October 30, 2019
  • 3 replies
  • 1792 views

I tried to test a UART link on the USART3 port of the STM32MP157C-DK2 board.

For that I followed the instructions of the Wiki for the modification of the Linux kernel:

  • I changed the settings in "arch / arm / boot / dts / stm32mp157a-dk1.dts" to put the USART3 in status = "okay"
  • I generated ".dtb" with the command "make dtbs"
  • I loaded it on the board and reboot it.

But after rebooting when I do "ls -l / dev / ttySTM *" I only get the ttySTM0 (for the UART_4).

When I do "dmesg | grep ttySTM *" I get the configuration for ttySTM3 (USART_2 for Bluetooth) and ttySTM0.

After several attempts I would like to know if you would have tracks?

This topic has been closed for replies.

3 replies

Olivier GALLIEN
Olivier GALLIEN
Technical Moderator
October 30, 2019

Hi @AZAMA​ 

As a first sanity check, are you sure you are booting using your custom dtb ?

One useful trick is to set green led on in it in order to secure this. ( cf https://wiki.st.com/stm32mpu/index.php/How_to_cross-compile_with_the_Developer_Package )

Are you overriding the default dtb configuration or did you create a fourth option entry in /boot/extlinux/extlinux.conf ?

Hope it help

Olivier

Olivier GALLIEN In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.
AZAMA
AZAMAAuthor
Associate
October 31, 2019

Hi @Community member​ 

Yes actually I did first test with the green LED which was halfway concluded.

At startup the LED turns on well but in return I lose the Ethernet connection so I do not touch it anymore.

But regarding the UART no answer.

Thanks,

Armand

Olivier GALLIEN
Olivier GALLIEN
Technical Moderator
October 31, 2019

Hi

Please have a look to following page :

https://wiki.st.com/stm32mpu/index.php/Trace_and_debug_scenario_-_UART_issue

Hope it help

Olivier

Olivier GALLIEN In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.
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