RF 433Mhz Serial Communication Module HC-12 range up to 1km

- Another product to replace Bluetooth + Antenna

HC-12 wireless serial port communication module is a new-generation multichannel embedded wireless data transmission module. Its wireless working frequency band is 433.4-473.0MHz, multiple channels can be set, with the stepping of 400 KHz, and there are totally 100 channels. The maximum transmitting power of module is 100mW (20dBm), the receiving sensitivity is -117dBm at baud rate of 5,000bps in the air, and the communication distance is 1,000m in open space.

There is MCU inside the module, and user don’t need to program the module separately, and all transparent transmission mode is only responsible for receiving and sending serial port data, so it is convenient to use. The module adopts multiple serial port transparent transmission modes, and user could select them by AT command according to use requirements. The average working current of three modes FU1, FU2 and FU3 in idle state is 80μa, 3.6mA an 16mA respectively, and the maximum working current is 100mA (in transmitting state).

This module can not work individually, at least 2 pcs would be needed to create the communication.

* Please also note that this module do not work with the 434Mhz Serial RF Module HC-11 .

Please solder the Antenna as below:
    

• Working frequency: 433.4MHz to 473.0MHz
• Supply voltage: 3.2V to 5.5VDC
• Communication distance: 1,000m in the open space
• Serial baud rate: 1.2Kbps to 115.2Kbps（default 9.6Kbps）
• Receiving sensitivity: -117dBm to -100dBm
• Transmit power: -1dBm to 20dBm
• Interface protocol: UART/TTL
• Operating temperature: -40℃ to +85℃
• Dimensions: 27.8mm x 14.4mm x 4mm

Connect RF Module with Arduino  (layadcircuits)

To use with an Arduino, the connections are simple.
Apply power using the Vcc and Gnd pins, connect the Rxd and Txd pins to the UART/Serial pins of the Arduino.
In the example below, softwareserial was used on pins 5 and 6.
Connect the Set pin to any free digital input pin on your Arduino.

The code is even more simplier, sending data is done using the Serial.print() or Serial.write() and receiving is done using the Serial.read(). Note that you may use software serial too. The basic code below configures the module to channel 1 and then allows you to communicate with another HC-12 using the Serial monitor. Upload the code and then open your serial monitor. Set the baud rate to 9600. Whatever you type next on the serial port is received by HC-12 modules with the same channel setting. So, if you have two of the above setup,you could send data back and forth using the serial monitor. 

#include <SoftwareSerial.h>

SoftwareSerial hc12(6, 5);

void setup() {
  pinMode(7,OUTPUT);
  digitalWrite(7,LOW); // enter AT command mode
  Serial.begin(9600);
  hc12.begin(9600);
  hc12.print(F("AT+C001\r\n")); // set to channel 1 
  delay(100);
  digitalWrite(7,HIGH);// enter transparent mode
}

void loop() {
  if(Serial.available()) hc12.write(Serial.read());
  if(hc12.available()) Serial.write(hc12.read());
}

The range of this device is specified by the manufacturer as 1000 meters maximum, that's a whole 1 kilometer! However, do note that such specifications are under very ideal conditions such as line-of-sight and high gain antennas. With the supplied spring antenna, a pair of HC-12 was tested at 100 meters, with one module indoors, while the other was outdoors. The results was excellent. For sure, this distance may be surpassed when both are outdoors. Within a typical-sized house, the module also works perfect indoors and is thus ideal for home automation applications.