Geekcreit 3-Pack HC-12 Wireless Serial Module SI4438 433MHz Transceiver - 1000M Range

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