7 years, 6 months ago.

USART Sents Junk data on STM32 nucleo

Hi, Am using stm32fnucleo board, while am trying to sent a message to pc over uart the docklight receives junk data.

This is the code i have used.

/media/uploads/stnucleo_sps/junk.png

and i get these result on docklight

/media/uploads/stnucleo_sps/junk1.png

can anyone help me?

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1 Answer

7 years, 6 months ago.

Hi Arun. Could you please test again using TeraTerm terminal program ?

Using your target board:

https://developer.mbed.org/teams/ST-Americas-mbed-Team/wiki/Creating-Console-Output

https://developer.mbed.org/handbook/Terminals

What are the results with TeraTerm configured as noted in the above webpage ?

Also, be sure your board contains the latest firmware:

https://developer.mbed.org/teams/ST/wiki/Nucleo-Firmware

Accepted Answer

Thankyou for the replay sir,

I will try with tera term also but still the problem exist. In the board i have made some modification, disconnect the SB13,SB14 and connected SB62,SB63 after this modification i got junk values on tera term . with the factory setup the teraterm shows nothing.

/media/uploads/stnucleo_sps/s.png

posted by Arun K 13 Sep 2016

Hi Arun. Is there a reason to rework the board as you have noted ? Unless you are using USART2 for another purpose, it will be best to restore the board back to factory settings for USART2. That is, remove SB62 and SB63. Short SB13 & short SB14. Then the default MBED library can communicate to use USART2 via the virtual com port on the USB interface. We have the most experience with Teraterm and know that program is stable to use. Please restore your PCB shorts and test again with Teraterm and post your results.

Reference: http://www.st.com/resource/en/schematic_pack/nucleo_64pins_sch.zip

  • schematics for your ST Nucleo board
  • see page 1 of the schematic to observe the direction flow for USART2 (USART_TX -> STLK_RX; USART_RX <- STLK_TX) so SB13 & SB14 must remain shorted (see pages 2 & 3 on how the main CPU mates with the ST Link CPU #U2)
posted by Sanjiv Bhatia 13 Sep 2016

Thankyou sir , My problem solved.. :)

posted by Arun K 15 Sep 2016