#include <ESP8266WiFi.h>
#include <espnow.h>

// REPLACE WITH RECEIVER MAC Address
uint8_t broadcastAddress[] = {0x58, 0xBF, 0x25, 0xD6, 0xF6, 0x8C};
#define REF_PIN 5
// Structure example to send data
// Must match the receiver structure
uint8_t data = 2;

unsigned long lastTime = 0;  
unsigned long timerDelay = 300;  // send readings timer

// Callback when data is sent
void OnDataSent(uint8_t *mac_addr, uint8_t sendStatus) {
  Serial.print("Last Packet Send Status: ");
  if (sendStatus == 0){
    Serial.println("Delivery success");
  }
  else{
    Serial.println("Delivery fail");
  }
}
 
void setup() {
  pinMode(REF_PIN, OUTPUT);
  // Init Serial Monitor
  Serial.begin(115200);
 
  // Set device as a Wi-Fi Station
  WiFi.mode(WIFI_STA);
  // Init ESP-NOW
  if (esp_now_init() != 0) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }

  // Once ESPNow is successfully Init, we will register for Send CB to
  // get the status of Trasnmitted packet
  
  esp_now_set_self_role(ESP_NOW_ROLE_CONTROLLER);
  esp_now_register_send_cb(OnDataSent);
  
  // Register peer
  esp_now_add_peer(broadcastAddress, ESP_NOW_ROLE_SLAVE, 1, NULL, 0);
}
 
void loop() {
  if ((millis() - lastTime) > timerDelay) {

    digitalWrite(REF_PIN, !digitalRead(REF_PIN));
    // Send message via ESP-NOW
    
    esp_now_send(broadcastAddress, (uint8_t *) &data, sizeof(data));
    
    lastTime = millis();
  }
}