Power requirements: 5V-18V power supply, the current required to provide 1.5A or more; TTL level serial port compatible with 3.3V and 5V microcontrollers. The real can and 51 / STM32 / MP430 and other single-chip direct communication; The initial use of computer debugging, it is recommended to use CP2102 USB-TTL module to the module power supply and communication; Using the MCU control module, you can also USB – 232 monitoring module to return the data on the instructions, great convenience to find the problem, especially suitable for small partners with 51 MCU. Standby in 30MA or so, you can set the sleep state of about 10MA low power consumption. Support SMS, GPRS data transmission, send MMS, DTMF, HTTP, FTP, PPP dial-up and other functions. At the same time the hardware contains all the way reset pin. This pin reset can be used to resolve a problem with the module.