A slave device that complies with Bluetooth communication protocol includes a communication module, a memory and a RF output module. The communication module can be operated to generate a driving signal. The memory stores an access code that complies with Bluetooth communication protocol and is electrically connected to the communication module. The memory is configured to determine whether or not to output the access code according to the driving signal output by the communication module. The RF output module is electrically connected to the memory so as to receive and output the access code.