ESP32_DEVBOARD_9141_test.INO

/*
  9141 UART test - ESP32 Dev board
*/

#define RXD2 22
#define TXD2 21

 void setup() {
   Serial.begin(9600);
   Serial1.begin(9600, SERIAL_8N1, RXD2, TXD2);
   delay(1000);
   Serial.println("Loopback program started");
   pinMode(RXD2, INPUT_PULLUP);
 }
 void loop() {
   if(Serial.available()){
     Serial1.write(Serial.read());  
   }
   if(Serial1.available()){
     Serial.write(Serial1.read());  
   }
 }