#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>

#define SERVICE_UUID        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"

BLECharacteristic *pCharacteristic;

void setup() {
  Serial.begin(115200);
  Serial.println("Starting BLE work!");

  BLEDevice::init("ESP32 Analog Advertiser");
  BLEServer *pServer = BLEDevice::createServer(); 
  BLEService *pService = pServer->createService(SERVICE_UUID);
  pCharacteristic = pService->createCharacteristic(
                                         CHARACTERISTIC_UUID,
                                         BLECharacteristic::PROPERTY_READ |
                                         BLECharacteristic::PROPERTY_NOTIFY
                                       );

  pService->start();
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->addServiceUUID(SERVICE_UUID);
  pAdvertising->setScanResponse(true);
  pAdvertising->setMinPreferred(0x06);
  pAdvertising->setMinPreferred(0x12);
  BLEDevice::startAdvertising();
  Serial.println("Characteristic defined! Now advertising analog values.");
}

void loop() {
  int analogValues[3];
  analogValues[0] = analogRead(A0);
  analogValues[1] = analogRead(A1);
  analogValues[2] = analogRead(A2);
  
  char valueStr[50];
  snprintf(valueStr, sizeof(valueStr), "A0:%d A1:%d A2:%d", analogValues[0], analogValues[1], analogValues[2]);
  
  Serial.println(valueStr);
  pCharacteristic->setValue(valueStr);
  pCharacteristic->notify();
  
  //delay(1000);
}