HC-12 Wireless Module Specifications:
Power Supply Voltage: 3.2V~5. 5V.(if the modules working long hours in emission state, suggested that when the power supply voltage is greater than 4.5V you need concatenating a 1N4007 diode to avoid module built-in LDO got fever).

Default Communication Distance: about 600 m (communication distance is adjustable up to 1000 m, air baud rate 5000 BPS).

Default Idle Current: 16 mA (modules in different working mode of different current). Default Working Mode :FU3, baud rate 9600bps, communication channel CHO01(433.4MHz) Operating Frequency Range (433.4-473.0 MHz, as many as 100 communication channel) maximum 100 mw fired power (can be set) Module supporting software upgrades.

FU1, FU2, FU3 and FU4 Four Serial Port Modes:
FU1: a more power-saving mode, the idle working current is about 3.6mA. In this mode, can also set 8 serial port baud rates as shown in the table below, but the air baud rate is unified to 250,000 bps.

FU2: power saving mode, the idle working current is about 80uA. In this mode, the module only supports the serial port baud rate of 1200 bps, 2400 bps and 4800 bps, and the air baud rate is unified to 250,000 bps. (After detection, there is a little bug when transmitting data in this mode, and users are not recommended to use FU2 mode for the time being)

FU3 mode works at full speed and the idle working current is about 16mA. In this mode, the module automatically adjusts the wireless transmission air baud rate according to the serial port baud rate.

FU4: ultra-long distance communication mode,the serial port baud rate is fixed at 1200bps,and the air baud rate is 500bps. In this mode, only a small amount of data is suitable for transmission.