Ref: www.linotux.ch/arduino/

HC-05 embedded Bluetooth serial communication module has two work modes: order-response work mode and automatic connection work mode . And there are three work roles (Master, Slave and Loopback) at the automatic connection work mode. When the module is at the automatic connection work mode, it will follow the default way set lastly to transmit the data automatically. When the module is at the order-response work mode, user can send the AT command to the module to set the control parameters and sent control order. The work mode of module can be switched by controlling the module PIN (PIO11) input level. Continue reading Bluetooth Module Serial Communication AT command set →