The HC-12 is a compact wireless serial communication module designed for transparent UART data transmission between microcontrollers, development boards, embedded systems, and other TTL serial devices. This version uses the Silicon Labs Si4438 RF transceiver together with the STMicroelectronics STM8S003F3P6 microcontroller.

The module operates across the 433.4MHz to 473.0MHz frequency range and supports up to 100 selectable communication channels with 400kHz channel spacing. It provides a maximum transmission power of up to 100mW or 20dBm and can achieve long-distance communication in open areas when suitable antennas, settings, and power conditions are used.

Key Features

• Si4438 Sub-GHz RF transceiver.
• STM8S003F3P6 onboard microcontroller.
• 433.4MHz to 473.0MHz operating frequency range.
• 100 selectable wireless channels.
• 400kHz channel spacing.
• Maximum RF output power up to 20dBm or 100mW.
• Simple TTL UART interface using TXD and RXD pins.
• Transparent wireless serial data transmission.
• Configurable using AT commands.
• Supports FU1, FU2, FU3, and FU4 operating modes.
• IPEX antenna connector and soldering point for a spring antenna.
• Communication distance of up to approximately 1km in open areas under suitable conditions.

Pin Configuration

• VCC: Module power input.
• GND: Ground connection.
• TXD: UART serial data output.
• RXD: UART serial data input.
• SET: Used to enter AT command configuration mode.

Typical Applications

• Wireless communication between Arduino boards and microcontrollers.
• Remote sensor and telemetry systems.
• Wireless data logging.
• Industrial monitoring and control systems.
• Home automation projects.
• Remote control and embedded communication applications.

Important: Communication range depends on the antenna type, transmission power, baud rate, power supply quality, surrounding interference, obstacles, and environmental conditions.