3 years, 10 months ago.

Serial communication not working

Maybe I'm doing it wrong... X-NUCLEO-IDB04A1 on a NUCLEO-F401RE

Default installation of the example works fine via BLE, as the phone detects HMR1 in the ALPWISE app (and simulates a heart beat) - but nothing via serial communication.

Serial communication starts only if I add some "print(anyStringHere)" ... but not if i plug in the shield!!

The NUCLEO alone answers via serial COM, but if i plug in the shield the COM port stays mute... any idea why this happens?

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3 Answers

3 years, 7 months ago.

same issue than you. did you find a solution, please ?

3 years, 7 months ago.

I think it's related to the Solid Bridges SB62 and SB63 (p. 26)


Ok i updated with the last Library and my windows phone see hrm1 the issue is on my pc already paires with a sensortag and now he think it is a sensor tag ☺

posted by Christophe Onillon 27 Jun 2016
3 years, 7 months ago.

By default PA2 and PA3 pins (i.e. D1 and D0 on Arduino connector) on STM32 Nucleo are connected to the ST-LINK/V2-1 interface. This means you can use the UART through the USB connection and the output of any printf() call will go to the PC by means of the USB Communication Device Class implementation.

I'm not sure I understood your question, though. Which pins are you using for UART? Do you have an example of code that doesn't work in your case?

Hi i use the rwo card above and i try to see after blé with my pc. But after loading the new fw i cannot see ble on my pc. I test with serial port of the debugger with putty to check communication.

401re and 4a1

Don t hesitate to comment ☺

posted by Christophe Onillon 27 Jun 2016

Sorry, but what is exactly your setup and your expected result with putty? What is the FW you are referring to? Did the same thing use to work earlier?

posted by Andrea Palmieri 27 Jun 2016

Hi Christophe, I need more information to be able to replicate your setup. Can you please answer Andrea's questions? Thanks.

posted by Antonio Vilei 27 Jun 2016

Ok i see now the device with the updated project from you yesterday. It reuest a pin code with my lumia 640 what is the default pin code i m fighting with my windows as it kept the information of the sensortag heart beat....

posted by Christophe Onillon 28 Jun 2016

The pin code is 123456. If you can't find your board correctly during a scan, please try to reboot your phone or PC. Phones and PCs have a cache of recently found BLE devices (even if they didn't pair with them) and if the information in the cache is wrong, rebooting usually clears the cache and solves the problem. Moreover, if you have previously paired with the BLE board, please make sure that you manually unpair it from your phone or PC before trying to connect again. Hope that helps.

posted by Antonio Vilei 29 Jun 2016