   // add service and characteristic
   blePeripheral.addAttribute(sliderService);
   blePeripheral.addAttribute(motor1Characteristic);
+  blePeripheral.addAttribute(motor2Characteristic);
+  blePeripheral.addAttribute(motor3Characteristic);
+  blePeripheral.addAttribute(motor4Characteristic);
 
   // begin initialization
   blePeripheral.begin();

#define BLE_RST   7

#define MOTOR_1_CONTROL_PIN   6

// create peripheral instance, see pinouts above
BLEPeripheral            blePeripheral        = BLEPeripheral(BLE_REQ, BLE_RDY, BLE_RST);

    Serial.println(central.address());
  }
}

void updateMotorSpeed(Servo& motor, unsigned char speed) {
  int microSeconds = map(speed, -128, 127, 1000, 2000);

  motor.writeMicroseconds(microSeconds);
}

