Features: With VCC, GND, TXD, RXD, KEY foot for the Bluetooth. Led indicate Bluetooth connection status, fast flash indicates unpaired, slow flash indicates AT mode, double flash indicates machine connected. Backplane settings LDO input voltage of 3.6-6V unpaired current is about 30mA, paired 10mA, input voltage prohibit more than 7V absolute prohibition of reverse power Interface level 3.3V, can be directly connected the various SCM (51, AVR, PIC, ARM, MSP430, etc.), the 5V MCU also can be connected directly, without MAX232 can not go through the MAX232 Open to effective distance of 10 meters, over 10 meters is also possible, but not of this the quality of the connection of the distance do to ensure. The pair later when full-duplex serial use, do not need to know anything about the Bluetooth protocol, but only supports 8 data bits, 1 stop bit, no parity communication format, which is the most commonly used communication format does not support other formats. Descriptions: Support to establish a Bluetooth connection through AT commands set the baud rate, passkey, set parameters are saved after. Specifications: Input voltage: 3.6-6V Working current: matching for 30 mA, matching the communication for 10 mA Output Power Class: Class 2 Size: 43mm x 15mm Color: Blue Package Includes: 1 x HC-05 Wireless Bluetooth RF Transceiver Module