buttonService with ReadWrite characteristic

#ifndef __BLE_BUTTON_SERVICE_H__
#define __BLE_BUTTON_SERVICE_H__

Serial pc(USBTX, USBRX);

class ButtonService {
public:
    const static uint16_t BUTTON_SERVICE_UUID              = 0xA000; /* define uuid for the service*/
    const static uint16_t BUTTON_STATE_CHARACTERISTIC_UUID = 0xA001; /* define uuid for the charcateristic "state" of the service  */
    const static uint16_t BUTTON_FIRST_VALUE_CHAR_UUID = 0xA002;
    
    ButtonService(BLE &_ble, bool buttonPressedInitial, uint8_t initialFirstValue) : ble(_ble), buttonState(BUTTON_STATE_CHARACTERISTIC_UUID, &buttonPressedInitial, GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY),firstValue(BUTTON_FIRST_VALUE_CHAR_UUID, &initialFirstValue)
    /* constructor of the class buttonService which inherits ble (which is an objet of class BLE), buttonState ( which is an object of the class ReadOnlyGattCharacteristic). When it inherits it also
    initializes the class with the proper parametes */
    {
        GattCharacteristic *charTable[] = {&buttonState, &firstValue}; /* prepare the characteristic table for the service that we are going to initialize */
        GattService         buttonService(ButtonService::BUTTON_SERVICE_UUID, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
                            /* Create the gatt service called buttonServices with uuid as previously defined, characteristics table just defined and the number of elements of the char table */
        ble.gattServer().addService(buttonService);
                            /* Add to the ble gattServer the service just defined */
    }

    void updateButtonState(bool newState) {
        ble.gattServer().write(buttonState.getValueHandle(), (uint8_t *)&newState, sizeof(bool));
        /* The attribute handle is a unique 16 bit identifier for each attribute on a particular gatt server. It the part of each attribute which makes it addressable and it is guaranteed not to change */
        /*new state is a bool so sizeof(bool)*/
    }
    
    int readFirstValue() {
        uint8_t buffer[10];
        int i;
        uint16_t lenght=sizeof(uint8_t);
        pc.printf("\nla lenght prima e %d\n ", (int)lenght);
        ble.gattServer().read(firstValue.getValueHandle(), buffer, &lenght);
        
        
        for(i = 0; i< 10; i++) {
            pc.printf("%d ", (int)buffer[i]);

        }
        pc.printf("\nla lenght e %d\n ",(int) lenght);
        pc.printf("\r\n");
        return ((int) buffer[0]);    
    }

private:
    BLE                              &ble;
    ReadOnlyGattCharacteristic<bool>  buttonState;
    ReadWriteGattCharacteristic<uint8_t> firstValue;
};

#endif /* #ifndef __BLE_BUTTON_SERVICE_H__ */