STLINK-V3-MINIE UART weirdness

[Ruggs]

Hello all and happy holidays,

I am having a bit of weirdness going on.

I have setup UART using stm32 HAL, confirmed it is working properly by stepping through (using an STLINK-V3-MINIE) as well as confirmed data is on the wire with a logic analyzer as well as a scope.

Furthermore, I have also run a loopback test to assure the com port is working for the V3-MINIE.

Despite this, I still can't get transmission to show up in my serial terminal (I did receive the message once but I beleive it was in a GDB session and I have not been able to replicate it since).

Any suggestions for anyone who has run into a similar issue with this device (for context I am using an STM32F411CEU6 black pill board)? I can provide any extra context where needed but I have run through the motions and still cannot seem to come to a solution.

[TDK]

What terminal program are you using? Some terminal programs don't show output until you send a newline.

[Ruggs]

I am running Tera Term (I've also tried PuTTY with the same result and double checked all terminal settings).

[Ruggs]

Just to throw some extra context your way I checked continuity between the m/f dupont wires i'm using. So if I can see the transmission with a logic analyzer from the pin, and then the loopback shows the com port works, and then I have continuity as well...I am sort of stumped haha. At this point I know it's something silly and I am going to laugh once resolved.

[Ruggs · Accepted solution]

Resolved. Everywhere I have read that you should cross the wires (makes sense right) for TX and RX (TX to the RX on the STLINK and vice-versa). 

I swapped them (TX TO TX and vice-versa) and it started printing in tera term. Haha.

I tried this last night and I didn't get anything printing. Weird. 

[Andrew Neil]

Do you have another USB-to-UART converter to try?

Do you have a genuine ST board to try?

[Ruggs]

I think it also could have been that I was using USB C to C cable for the STLINK when I tried to swap the wires previously (I read that it requires a USB A to C cable in the documentation earlier so swapped it).