/* Peripheral 2 sending data to central */

#include <ArduinoBLE.h>
unsigned long DATA;
unsigned int i;

BLEService dataService("19B10000-E8F2-537E-4F6C-D104768A1214");  
BLEUnsignedLongCharacteristic switchCharacteristic("19B10001-E8F2-537E-4F6C-D104768A1214", BLERead | BLEWrite);

const int ledPin = LED_BUILTIN; 

void setup() 
{
  
 // Serial.begin(9600);
 //Serial.begin(19200);
 Serial.begin(115200);
  while (!Serial);
  
  pinMode(ledPin, OUTPUT);

  if (!BLE.begin()) 
  {
    Serial.println("starting BLE failed!");
    while (1);
  }

  BLE.setLocalName("PERIPHERAL-2");
  BLE.setAdvertisedService(dataService);

  dataService.addCharacteristic(switchCharacteristic);

  BLE.addService(dataService);
  switchCharacteristic.writeValue(0);
  BLE.advertise();
  Serial.println("PERIPHERAL-2");
}

void loop()
{
  BLEDevice central = BLE.central();
  for(i=0; i<3; i++)
  {
    DATA+= random(5000,8000);
  }
  DATA=DATA/3;
  if (central) 
  {
 //   Serial.print("Connected to central: ");
 //   Serial.println(central.address());
     
    while (central.connected())
    {
      if (switchCharacteristic.written())
      {
         
        if (switchCharacteristic.value()) 
        {  
          digitalWrite(ledPin, HIGH);          
     //     Serial.print("Connected to central: ");
          switchCharacteristic.writeValue(DATA);
          Serial.print("[");
          Serial.print(switchCharacteristic.value());
          Serial.print("]");
           Serial.print("\n");
       }
        else
        {                              
          digitalWrite(ledPin, LOW);           
        }
      }
    }
 //   Serial.print(F("Disconnected PERIPHERAL-2 from central: "));
  //  Serial.println(central.address());
  }
}