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Sware.1
Associate II
July 6, 2020
Question

On Windows 10 for STM32F407VG MCU, Virtual Com port shows only blank screen on putty.

  • July 6, 2020
  • 4 replies
  • 3907 views

My work environment as below :

1. Window 10 (Version 10.0.18362 Build 18362)

2. Laptop processor: AMD PRO A12-8830B R7

3. My Discovery Board: STM32F407VG MCU

 4. Driver Installed : 

   en.stsw-link009 and Virtual Com port : VCP_V1.5.0_Setup_W8_x64

5. Coding Using MBED online compiler.

Issue : When I access COM3 port using Tera Term / putty it shows me blank screen,

Why it don't print Helllo World on putty or Teram Term console ???

But On this board I can run LED blinking programs successfully.

Code :

#include "mbed.h"

Serial pc(USBTX, USBRX); // tx, rx

int main()

{

  while(1) {

    pc.printf("Hello World!\n");

    wait(0.8);

  }

}

Kindly refer below screen snaps of Virtual Com Port, Tera term and Code for more detail.

0693W000001sCcEQAU.png

0693W000001sCc9QAE.png

0693W000001sCcJQAU.png

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4 replies

TDK
July 6, 2020

Check that your port settings match on both sides. Probe the lines to make sure a signal is actually sent.

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Sware.1
Sware.1Author
Associate II
July 7, 2020

@TDK​ : Kindly elaborate what exactly I should do to port settings match on both sides ? I spend lot of hours in fixing this issue.But not able to find any fix for it.

TDK
July 8, 2020

You'll need to dig into the documentation of whatever software you're using. It's not clear if Serial is using a UART port to talk to the ST-Link or if you're using the USB itself to act as a VCP. I suspect it is the former, in which case the baud rate, data bits, parity and stop bit settings need to match on TeraTerm and within your STM32 UART initialization.

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Sware.1
Sware.1Author
Associate II
July 9, 2020

I tried with baud rate 9600 and 115200, But it don't work for me.

Any more suggestion ?