Hello. For some reason, UART1 does not work for transmission, only for reception. The transmitter pin itself is definitely working, I checked by switching this pin to output mode, and then switching it to a high/low logical level, everything works properly, the level on the Pin changes. How I check the UART itself: I installed picocom, shorted the TX and RX pins, and I’m trying to see what I’m sending. For UART2 this method works as it should, but UART1 only works for reception. I realized this when I opened the TX and RX, and was able to receive incoming data sent through the USB-UART converter.