STM32 UART/USART receive issue(without interrupt)

[C S]

Posted on September 04, 2017 at 08:51

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[Jagadish]

Posted on September 06, 2017 at 21:48

Hi Chirag,

I had faced this problem with L031 board. Have a look at the schematics --

http://www.st.com/en/microcontrollers/stm32l476rg.html

 and check if the UART pins i.e STLK_TX and STLK_RX are the same as configured using the STMCube. You can check the UART pins in a file that reads something like stm32l4xx_hal_msp.c, and search for void HAL_UART_MspInit(UART_HandleTypeDef* huart). To receive from hyperterminal these pins should match the UART pins mentioned in schematic.  

Hope this helps.

Regards,

Harsha

[Tesla DeLorean]

Posted on September 06, 2017 at 22:53

So what pins does this supposedly use? Save me having to dig through the docs for things you should already be aware of.

Does HAL_UART_Receive() return an error? When you uses a debugger what do you see in the buffer?

Note that an array with 10 elements has them numbered 0 thru 9

data1[10] = data[10]; // this is out side the bounds of the array, not clear on the purpose of this code

Try echoing back one character at a time.

[Brian TIDAL]

Posted on September 06, 2017 at 23:37

Hi Chirag,

Can you confirm you are using USART2 with PD5 (USART_TX) and PD6 (USART_RX)? Is USART2 connected to PC through the ST-Link Virtual Com Port (VCP)? In such case, there is no modification needed on the board, and you should be able to send/receive through the VCP thanks to the ST-Link USB cable. See

http://www.st.com/content/ccc/resource/technical/document/user_manual/d1/84/86/4b/08/82/47/91/DM00172179.pdf/files/DM00172179.pdf/jcr:content/translations/en.DM00172179.pdf

User manual Discovery kit with STM32L476VG MCU § 7.9 USART configuration.

I would not recommend to use PA2 and PA3 as I would conflict with JOY_RIGHT and JOY_UP (or you'll have to remove R52 & R56 resistors). 

Regards

Bruno