HC-12 433Mhz RF Module

HC-12 433MHz Wireless Serial Port RF Transceiver Module 100mW with Helical Antenna

UART TTL AT Command 100 Channel Long Range 1000m Telemetry Remote Control Data Logging Smart Home Irrigation Greenhouse Farm Drone Alarm

     The HC-12 is a two-way (transceiver) wireless serial port module operating in the 433.4MHz - 473.0MHz band. Its on-board microcontroller manages the radio link by itself: data written to its TTL UART (TX/RX) comes out unchanged from the UART of the HC-12 on the other side, replacing a wired serial line. It has 100 channels spaced 400kHz apart and transmit power adjustable up to 100mW (20dBm); the factory setting is FU3 mode, 9600bps and channel 1 (433.4MHz).

     In open space it can communicate up to 1000m at an air data rate of 5000bps; with the factory setting the range is about 500m - 600m. It is powered from 3.2V - 5.5V and connects directly to control boards with 3.3V or 5V UART. Channel, UART speed, working mode and transmit power are set with AT commands entered via the SET pin and are kept even when power is removed.

     It measures 27.5mm x 13.5mm and weighs 1.5gr. A 25mm spring (helical) antenna is included; the antenna is soldered to the antenna hole on the board, or an external antenna is plugged into the IPEX socket. With two or more HC-12 modules it is used for sensor data collection, remote control, telemetry and converting a wired serial line to wireless. It does not communicate with the HC-11; an HC-12 is needed on the other side as well.

Key features:

     Makes the serial line wireless: Data written to the TX/RX line comes out unchanged from the HC-12 on the other side; no extra protocol or library is needed, and existing serial code works unchanged.

     Long range: Up to 1000m in open space at 5000bps air data rate, about 500m - 600m with the factory setting. Receiver sensitivity is about -117dBm at 5000bps.

     100 channels, adjustable power: 100 channels in 400kHz steps between 433.4MHz and 473.0MHz; several HC-12 pairs can work on different channels in the same area. Transmit power is adjustable in 8 levels up to 100mW (20dBm).

     Set with AT commands: When the SET pin is pulled to GND the module enters setup mode; channel (AT+C), UART speed (AT+B), working mode (AT+FU) and transmit power (AT+P) are changed, and settings are kept after power off.

     Two antenna options: The included 25mm spring antenna is soldered on, or a cabled external antenna is plugged into the on-board IPEX socket for longer range.

Features:

• Product type: 433MHz two-way wireless serial port (UART) RF transceiver module
• Model: HC-12
• Operating frequency: 433.4MHz - 473.0MHz
• Number of channels: 100 channels, 400kHz channel spacing (factory setting CH001, 433.4MHz)
• Transmit power: up to 100mW (20dBm), adjustable in 8 levels (AT+P1 - AT+P8)
• Communication distance: up to 1000m in open space (at 5000bps air data rate); about 500m - 600m with the factory setting
• Receiver sensitivity: about -117dBm (at 5000bps air data rate); decreases as the air data rate increases
• Interface: TTL UART (TXD, RXD), compatible with 3.3V and 5V level boards
• UART speed: 1200bps - 115200bps (factory setting 9600bps, 8N1)
• Working modes: FU1, FU2, FU3 (factory setting FU3); two communicating modules must use the same mode, speed and channel
• Operating voltage: 3.2V - 5.5V DC (prefer 3.3V supply for long-term use)
• Operating current: about 16mA idle in FU3 mode; up to about 100mA when transmitting at full power
• Pins: VCC, GND, RXD, TXD, SET (5 pins, 2.54mm pitch, pin header not fitted)
• Antenna connection: solder hole for the spring antenna and IPEX (U.FL) socket for an external antenna
• Compatibility: communicates only with HC-12; does not communicate with HC-11
• Operating temperature: -10°C - 75°C
• Color: Blue
• Antenna length: 25mm (spring / helical antenna)
• Dimensions: 27.5mm x 13.5mm x about 4mm (excluding spring antenna)
• Weight: 1.5gr

Usage information:

• Connection: connect VCC to a 3.3V - 5V supply, GND to the control board GND, the HC-12 TXD pin to the board RX pin and the RXD pin to the board TX pin (crossed). When the SET pin is left open the module works in normal communication mode.
• Setup mode: pull the SET pin to GND; the module accepts AT commands at its current UART speed (factory setting 9600bps); if the UART speed is unknown, power the module up with the SET pin held at GND and it enters setup mode at 9600bps 8N1. The "AT" command is answered with "OK". AT+B19200 sets the UART speed, AT+C021 the channel (channel 21 is 441.4MHz), AT+FU3 the working mode and AT+P8 the highest transmit power. When the SET pin is released the setting takes effect and is stored.
• Set the two HC-12 modules that will communicate to the same channel, the same UART speed and the same working mode; two modules left at the factory setting communicate directly.
• Each 6dB reduction in transmit power roughly halves the communication distance; at short range choose low power to reduce current consumption.

Areas of use:

•  Converting a wired serial line (UART) to wireless
•  Data collection and logging from remote sensors
•  Farm, greenhouse and garden irrigation control
•  Communication between smart home and home automation devices
•  Drone, model vehicle and boat telemetry
•  Remote control systems
•  Alarm and security systems
•  Weather stations and environmental measuring points
•  Wireless communication inside and between buildings
•  Robot and vehicle tracking applications

Precautions:

•  The HC-12 communicates only with another HC-12; it does not communicate with HC-11, nRF24L01 or 433MHz ASK modules. At least two HC-12 modules are needed for a link.
•  If the module transmits for long periods with a supply above 4.5V, connect a 1N4007 diode in series with the supply to reduce heating, or use a 3.3V supply.
•  About 100mA is drawn when transmitting at full power; the supply must deliver this current without a voltage drop.
•  Pairs working at a high air data rate (above 58000bps) and at short range (10m) can interfere with each other; if you use several pairs, leave at least 5 channels between them.
•  The 1000m range is an open-space value; buildings, trees and metal obstacles shorten the range considerably. Do not run the module at high power without an antenna.

Package contents:

•  1 pcs HC-12 433MHz Wireless Serial Port RF Module
•  1 pcs 25mm spring (helical) antenna
•  Note: Pin header and IPEX external antenna are not included in the package.