Seeed Studio XIAO RP2040 Serial Problem

[pacecar3]

Hello together,

I want to use two serial Ports with Seeed Studio XIAO RP2040, but if i use Serial2 with defined pins and upload the compiled code to the device it freezes immediately.

So how can i use Serial1 default Pins (6/7) and Serial2 with custom pins?

[horace]

not sure if it helps but using a Raspberry Pi Pico I had Serial1 working on pins GP0 and GP1 (default) just setting the baudrate

  Serial1.begin(115200);

and Serial2 on GP4 and GP5 using setTX() and setRX() functions, e.g.

// Raspberry Pi Pico RP2040  Serial2 test - for loopback test connect pins Tx GP4 and Rx GP5
#include <Arduino.h>

// Note 
// Serial is the USB serial for program loading and serial mointor
// there are two hardware serial ports UART0 and UART1
//  Serial1 is mapped to UART0 on Rx pin GP1 Tx pin GP0
//  Serial2 is mapped to UART1 on Rx pin GP5 Tx pin GP4

void setup() {
  // initialize both serial ports:
  Serial.begin(115200);
  delay(2000);
  // reassign pin numbers for Serial1
  Serial2.setTX(4);   // note cannot swap pins
  Serial2.setRX(5);
  Serial2.begin(115200);
  Serial.println("\n\nRaspberry Pi Pico RP2040 serial2  test Rx pin GP5 Tx pin GP4 ");
  Serial.write("   for loopback test connect pin GP4 to pin GP5\n");
}

void loop() {
  // read from port 1, send to port 0:
  if (Serial2.available()) {
    int inByte = Serial2.read();
    Serial.write('>');
    Serial.write(inByte);
  }

  // read from port 0, send to port 1:
  if (Serial.available()) {
    int inByte = Serial.read();
    //Serial.write(inByte);
    Serial2.write(inByte);
  }
}

when I attempted to use Serial2 on GP6 and GP7

  // reassign pin numbers for Serial2
  Serial2.setTX(6);  
  Serial2.setRX(7);
  Serial2.begin(115200);

it failed and hangs the processor - have to reset using BOOTSEL button