Why does Serial give the wrong result?

Question

Arduino

I connect such a BT201 module to UNO via UART
, it receives and executes AT commands, but it gives back some kind of dregs.

The top result should be QM+01\r\n , and there are some minuses in the codes.

Answer 1

SoftwareSerial works disgustingly on 115200, most likely it will send and receive garbage. Lower the speed to 38400. At 57600 I got AltSoftSerial, but there the pins are hard-wired and timer 1 is used.