433Mhz OOK with Funky v2 to remotely control power sockets

Here is a 15 minute project: control 433Mhz RF sockets with the Funky v2: I have a 433Mhz OOK transmitter/receiver, I don’t even recall where I got them. These are widely available on ebay for less than $5 delivered. I used FuzziLogic’s 433Mhz Arduino library for the purpose. First I wired the receiver on a breadboard and used the ShowReceivedCode example to get the period and codes for ON / OFF for House A, application 1. Then I used the so received code and period value to send is as raw data telegram using this simple sketch:

#include <RemoteTransmitter.h>  
//https://bitbucket.org/fuzzillogic/433mhzforarduino/

RemoteTransmitter RemoteTransmitter(A0,323,8);

void setup() {
  //See example Show_received_code for info on this
pinMode(A0, OUTPUT);
pinMode(2, OUTPUT);
digitalWrite(2,LOW);
}

void loop() {

  unsigned long code;
  unsigned long receivedCode;
  unsigned int period;

 //Used this sketch to read the code: https://bitbucket.org/fuzzillogic/433mhzforarduino/src/edabcd754f5b/RemoteSwitch/examples/ShowReceivedCode/ShowReceivedCode.ino?at=default 
  receivedCode=172771;
  period=323;

  //Copy the received code. 
  code = receivedCode & 0xFFFFF; //truncate to 20 bits for show; receivedCode is never more than 20 bits..

  //Add the period duration to the code. Range: [0..511] (9 bit)
  code |= (unsigned long)period << 23;

  //Add the number of repeats to the code. Range: [0..7] (3 bit). The actual number of repeats will be 2^(repeats), 
  //in this case 8
  code |= 3L << 20;

  RemoteTransmitter::sendTelegram(code,A0);

  //Wait 5 seconds before sending.
  delay(5000);

  receivedCode=172770;
  period=323;

  //Copy the received code. 
  code = receivedCode & 0xFFFFF; //truncate to 20 bits for show; receivedCode is never more than 20 bits..

  //Add the period duration to the code. Range: [0..511] (9 bit)
  code |= (unsigned long)period << 23;

  //Add the number of repeats to the code. Range: [0..7] (3 bit). The actual number of repeats will be 2^(repeats), 
  //in this case 8
  code |= 3L << 20;

  //Retransmit the signal on pin 11. Note: no object was created!
  RemoteTransmitter::sendTelegram(code,A0);
  delay(5000); 

}

Works as a charm, switching the power socket on and off every 5 seconds. I find this approach much safer and less intrusive compared to wiring relays. Since the Funky v2 acts as a virtual serial CDC device, it is really easy to control RF switches from serial of a laptop/Raspbrry Pi too. I didn’t wire an antenna, but even without one I get 3m range.

P.S. This blog makes 1 year today 🙂