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

//MAC receiver (who is sending)
uint8_t brcAdr[]={0x8C,0xAA,0xB5,0x84,0xFB,0x90};

esp_now_peer_info_t peerInfo; //Object to know when a message arrives and what to do

//Sending callback
void OnDataSent(const uint8_t*mac_addr, esp_now_send_status_t status){
  Serial.print("Send Status: ");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Ok" : "Error");
}

//Receiving Callback
void OnDataRecv(const uint8_t*mac, const uint8_t*data,int len){ //Function for data received
  Serial.println("Msg received: ");
  char rcvstring[len];
  memcpy(rcvstring,data,len); //copy of rcvstring on data, with lenght len
  Serial.println(String(rcvstring));
}

void setup() {
  Serial.begin(115200);
  WiFi.mode(WIFI_STA); //enable WIFI module
  esp_now_init(); //initialize espnow protocol
  //send callback
  esp_now_register_send_cb(OnDataSent); //register the status 
  //receive callback
  esp_now_register_recv_cb(OnDataRecv); //what to do when something is received
  //Peer Registration
  memcpy(peerInfo.peer_addr,brcAdr,6); //who to transmit this data
  //copy of peerInfo.peer_addr to comunicate with brcAdr with lenght 6

  peerInfo.channel=0; //set channel of wifi
  peerInfo.encrypt=false; //not encrypt
  esp_now_add_peer(&peerInfo); //add the peer peerInfo
}

void loop() {
  //Read from the serial
  while (!Serial.available()); //Wait for input
  String message = Serial.readStringUntil('\n');
  //send the message of the brcadr with a message length, +1 to add the end of /0.
  esp_now_send(brcAdr,(uint8_t*)message.c_str(),message.length()+1);
}