ESP32_OSC_IMU/lib/M5Stack/examples/Unit/RS485_SP485EEN/RS485_SP485EEN.ino

/*
    Description: Use RS485 Unit for serial communication, continuously send "Hello", and display the received content on the screen.
*/
#include <M5Stack.h>
#define RX_PIN      16
#define TX_PIN      17  

#define X_OFF 160
#define Y_OFF 30

int i=0,s=0;

void header(const char *string, uint16_t color){
    M5.Lcd.fillScreen(color);
    M5.Lcd.setTextSize(1);
    M5.Lcd.setTextColor(TFT_MAGENTA, TFT_BLUE);
    M5.Lcd.fillRect(0, 0, 320, 30, TFT_BLUE);
    M5.Lcd.setTextDatum(TC_DATUM);
    M5.Lcd.drawString(string, 160, 3, 4);
}

void setup() {
  M5.begin();
  M5.Power.begin();

  header("RS485 Unit test", TFT_BLACK);
  M5.Lcd.setTextFont(2);
  M5.Lcd.setTextColor(TFT_WHITE, TFT_BLACK);
  Serial.begin(115200);   
  Serial2.begin(115200, SERIAL_8N1, RX_PIN, TX_PIN);   
}


void loop() {
  
  Serial2.write("Hello\n");

  if(Serial2.available()){
   M5.Lcd.print(char(Serial2.read()));
 }
  delay(100);
}