You can use it with Freaduino(work on 3.3V mode) and other MCU. Using with our APP,you can easily control robot ,drone and others by BLE. Adopting TI CC2540 chip with 256 KB space, the BLE HC module can use BLE technology through the simple IO control, between the module and mobile, also between the module and module. The BLE module has both Master and Slave Mode, with the command control, through the serial port capable of switching module master-slave role, capable of configuring the serial port baud rate, capable of modifying the module radio name, capable of modifying the broadcast interval and the connection interval. Using this module, users can quickly transmit data in the form of Bluetooth packet.