#include <ArduinoBLE.h>

#define LED_BUILTIN 8

BLEService BlinkySvc("19b10000-e8f2-537e-6969-d104768a1214"); // from https://www.guidgenerator.com/

BLEIntCharacteristic BlinkyChar("19b10001-e8f2-537e-6969-d104768a1214", BLERead | BLEWrite | BLENotify);

BLEDescriptor FamilyDesc( "2969", "CanHobby" );

bool CX;   //  we are Connected.

void setup() {
 
 Serial.begin( 115200 );
 printf( "Built-In is 0x%02x\n", LED_BUILTIN );
  pinMode( LED_BUILTIN, OUTPUT );                                      //set pins as outputs and set LED's HIGH (HIGH is off for this board)
  digitalWrite( LED_BUILTIN, LOW );

  if (!BLE.begin()) {                                           // begin initialization
    delay( 200 ); // while (1);                                                  // wait until initialization complete
  }
 printf("I waited 2 secs\n");
  BLE.setLocalName("BlinkyBLE");                                  // set advertised local name
  BLE.setAdvertisedService( BlinkySvc );                         // set advertised service UUID
  BlinkySvc.addCharacteristic( BlinkyChar );              // add the red characteristic to the service
  BlinkySvc. 
  
  BLE.addService( BlinkySvc );                                   // add service
  
  BLE.advertise();   // start advertising

  printf("end Setup\n");
}

uint8_t BlinkyCharVal;
 
void loop() { 

  BLEDevice central = BLE.central();                            // listen for BLE devices to connect:
 
  if (central) {                                                // if a central is connected to peripheral:

   printf("Phone connected to BlinkyBLE\n"); // put code here to preform 1 time when device is connected
   CX = true;
                                                                
    while (central.connected()) {                               // while the central is still connected to peripheral

/****
    if( BathChar.valueUpdated() ) {    
      BathChar.readValue( BathCharVal );
      printf("BathCharVal = 0x%X\n", BathCharVal );
      if( BathCharVal & 1 ) { printf("BathCharVal id Odd\n"  ); }
      else {                  printf("BathCharVal id Even\n" ); }
                                    }
******/
                                    
    // if there is an update from Android App, change light ON (0) or OFF (1) 
      if ( BlinkyChar.written()) { BlinkyCharVal = BlinkyChar.value();
        printf("Blinky Written = 0x%0X\n", BlinkyCharVal );
        digitalWrite( LED_BUILTIN, BlinkyCharVal );
   }
  }         // end of while loop
 }          if(CX) { printf("not connected\n"); CX=0; } //  digitalWrite( LED_BUILTIN, HIGH ); }
}           // end of loop