How to use more than one serial Port

[Pacecar3]

Hello together,
I need for a project two serial ports, but if i check the pinout i only find one UART. Also the Hardware freeze immediately if i use Serial2 in my code.

So is there a way to and an additional Serial (with custom Port Definition) or is the XIAO RP2040 the wrong HW for my project?

[PJ_Glasso]

I see this code, uses soft serial. I have something similar on a ESPc3 talking to GPS and Serial port. Works very well.

#include <SoftwareSerial.h>

SoftwareSerial mySerial = SoftwareSerial(21,20); // these are GPIO pins on Arduino RP2040 D9 and D8

void setup(){
    Serial.begin(9600); // USB
    while(!Serial); // For USB 
    Serial1.begin(9600); // for the provided UART port on the Nano RP2040
    mySerial.begin(9600); // our custom created Serial UART interface
}

void loop(){
    Serial.write("Hello World"); // writes to USB serial monitor
    Serial1.write("AT"); // writes to device connected to TX and RX of the nano rp2040 e.g GSM
    mySerial.write("AT");  // writes to device connected to D9 and D8 of the nano rp2040 e.g another GSM
}

HTH
GL PJ

AFAIK, it’s all or nothing when using softserial. use it for both ports.