anteo c

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7 years, 11 months ago.

nucleo f401re sends weired string every time a serial connection is opened

So till now i was working with f103 but cause of memory issues i changed to f401. everything works as with f103 did but now i am seeing something strange. i am using coolterm to communicate with the board but every time i connect to the board i am getting such a string "$$$.072002210B6067363424F12B" in the coolterm console. This happens also with the blinky led example from the online compiler. when the connection stays open everything is ok but if i disconnect and connect again the first thing i get is that string.

This did not happen with f103. Does anyone know where is it coming from?

I am working on Mac and i tested the same thing on windows and it does not happen. So the problem is only on Mac. Based on the first two comments beneath i want to answer that the pins are same on f103 and and f401. I am using the same program with same code but i do not think that is a code issue. As i mentioned the weired string comes only when a connection is opened. This happens also when the board does not have a code at all. When the board has a code in it all code messages appear fine.

posted by anteo c 25 May 2016

I updated the firmware of the board through the java app offered from st.com and since than the problem dissappeared.

posted by anteo c 26 May 2016

2 Answers

ovi rahman
7 years, 11 months ago.

have you checked if the f103 and f104 shares the same pins? are you using the same program from f103 on your f104? they could have different clock settings, I would rather copy and paste the code or try uart from scratch on the f104. every time I got weird characters, it was because of a weird clock issue. probably wrong baud. make sure everything on your program matches the settings on your device. also try it on hyper terminal or hercules just in case

Andrew Lindsay
7 years, 11 months ago.

I've seen this on another ST Micro based board and I always assumed it was some bootloader debug message as hitting reset didnt fix it. Powering off then on again and re-flashing fixed it.

Andrew