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

#define LEDpin D7  //Connect LED on pin 2

// Structure example to receive data
// Must match the sender structure
typedef struct struct_message {  //create a structure called "message" and add the contents of the messag
  int btnstate;  //integer value "State"
} struct_message;

struct_message myData; // Create a struct_message called myData

// Callback function that will be executed when data is received
void OnDataRecv(uint8_t *mac, uint8_t *incomingData, uint8_t len) {
  memcpy(&myData, incomingData, sizeof(myData));
  Serial.print("Received state: ");
  Serial.println(myData.btnstate);
  Serial.println();
}

void setup() {
  pinMode(LEDpin, OUTPUT); //Define LED as output
  Serial.begin(115200);  // Initialize Serial Monitor
  WiFi.mode(WIFI_STA);   // Set device as a Wi-Fi Station

  // Init ESP-NOW
  if (esp_now_init() != 0) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }

  // Once ESPNow is successfully Init, we will register for recv CB to
  // get recv packer info
  esp_now_set_self_role(ESP_NOW_ROLE_SLAVE);
  esp_now_register_recv_cb(OnDataRecv);
}

void loop() {
  if (myData.btnstate == 0) {
    digitalWrite(LEDpin, HIGH);
  } else {
    digitalWrite(LEDpin, LOW);
  }
}