The function does not work in ESP8266

[MicroBahner]

@arduino556665

void led_blink(){
  unsigned long timing = 0;
  if (millis() - timing > 2000){
    timing = millis();
    led_state = !led_state;
    digitalWrite(R1, led_state);

This will not work, because your 'timing' variable is a local dynamic variable, that will be newly created and set to 0 with every call to led_blink. You must define this as a static variable.

static unsigned long timing = 0;