#include #define RXD2 16 #define TXD2 17 #define LOG_LOCAL_LEVEL ESP_LOG_INFO #include "esp_log.h" #include HardwareSerial Serial2(1); volatile char cmd = 'z'; void setup () { Serial2.begin(9600, SERIAL_8N1, RXD2, TXD2); } void loop () { if (Serial2.available() > 0) { cmd = Serial2.read(); } if (cmd == 'x') { Serial2.print('x'); } }