body { font-family: Arial, sans-serif; } h2, h3 { color: #333; } ul { list-style-type: none; padding-left: 0; } ul li { margin-bottom: 5px; } p { margin-bottom: 20px; } HC-12 Wireless Module Important Update: The chip has been upgraded from SI4463 to SI4438 beginning from November 26, 2019. Note: HC-11 and HC-12 modules cannot communicate with each other and must be used in pairs. Key Features: Supply Voltage: 3.2V to 5.5V. For long hours in emission state, use a 1N4007 diode if using a voltage above 4.5V to prevent heating. Communication Range: Default range of 600m, adjustable up to 1000m at 500bps baud rate. Idle Current: 16mA (varies with operating modes). Dimensions: 27.8 x 14.4 x 4mm. Operating Frequency: 433.4-473.0MHz, supporting up to 100 communication channels. Transmit Power: Max 100mW, adjustable. Software Upgrades: Supported. Factory Settings: Mode FU3, 9600bps baud rate, Channel CH001 (433.4M). Transmission Modes: Four modes for versatile applications. Integration: Built-in MCU for programming-free usage; interactive via serial port. Data Transmission: Unlimited byte transmission in FU1/FU3 modes. Connection Support: One-to-one, one-to-many, many-to-one, and many-to-many transparency. Technical Parameters: Model: HC-12 Size: 27.4 x 13.2 x 4mm Frequency: 433.4 ~ 473.0MHz Communication: UART 3.3V/5V TTL Antenna: Spring or socket Voltage: 3.2-5.5V Idle Current: 16mA Working Humidity: 10%-90% Power: 20dBm (MAX) Operating Temperature: -25°C to +75°C Storage Temperature: -40°C to +85°C AT Command Set: These commands configure module parameters. After setting, exit the mode for changes to take effect. Modified settings are retained through power cycles. Entering Command Mode: Method 1: During use, set the 5th pin "SET" to low. Method 2: On startup, set the "SET" pin low. Exit by releasing the "SET" pin. Serial format is fixed at 9600, N, 1. Instructions: AT: Test module (returns "OK"). AT + Bxxxx: Change baud rate (returns "OK + Bxxxx"). Example: command "AT + B19200" sets baud rate to 19200bps. AT + Cxxx: Change wireless channel (returns "OK + Cxxx"). Channels 001-127, default is 001 (433.4MHz). AT + FUx: Change transmission mode. FU1, FU2, FU3 are available. Default is FU3. AT + Px: Adjust transmit power level (returns "OK + Px"). Level 8 is max power. Transparent Transmission Modes: FU1: Power-saving, idle current ~3.6mA. FU2: Ultra power-saving, idle current ~80uA. Limited baud rates supported. FU3: Full speed, default mode, idle current ~16mA. FU4: Long-distance, fixed baud rate 1200bps, idle current ~16mA. Package Includes: 3 x HC-12 Modules
