#include <esp_now.h>
#include <WiFi.h>

// Receiver MAC Address
uint8_t broadcastAddress[] = {0x34, 0xCD, 0xB0, 0xD0, 0x76, 0x40};

// Data to send, dose not matter in this code as any data will make the receiver blink
typedef struct struct_message {
  char a[16];
} struct_message;

struct_message myData;

esp_now_peer_info_t peerInfo;

#define LEDPIN 0
#define REEDSENSORPIN 4

// callback when data is sent
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("\r\nLast Packet Send Status:\t");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}
 
void setup() {
  pinMode(REEDSENSORPIN, INPUT);
  pinMode(LEDPIN, OUTPUT);

  Serial.begin(115200);
  Serial.println("Hello World!");
 
  WiFi.mode(WIFI_STA);

  // Init ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }

  esp_now_register_send_cb(OnDataSent);
  
  // Register peer
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;
  
  // Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }

  // 2xShort
  digitalWrite(LEDPIN, 1);
  delay(50);
  digitalWrite(LEDPIN, 0);
  delay(50);
  digitalWrite(LEDPIN, 1);
  delay(50);
  digitalWrite(LEDPIN, 0);
  delay(50);
  // Long
  digitalWrite(LEDPIN, 1);
  delay(200);
  digitalWrite(LEDPIN, 0);
  delay(100);
  // Normal
  digitalWrite(LEDPIN, 1);
  delay(100);
  digitalWrite(LEDPIN, 0);
  delay(100);
}
 
void loop() {
  // Set values to send
  strcpy(myData.a, "Heartbeat");
  
  if (!digitalRead(REEDSENSORPIN)) {
    digitalWrite(LEDPIN, 1);
    esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));
    if (result == ESP_OK) {
      Serial.println("Sent with success");
    }
    else {
      Serial.println("Error sending the data");
    }
  } else {
    digitalWrite(LEDPIN, 0);
  }
   
  delay(300);
}