Raspberry Pi - Controlling 433 MHz remote outlets

In my previous post here, I tried to use a cheap 433 MHz transmitter to replicate the 433 MHz remote functionality but landed up hacking the remote to send the codes instead. The main issue I was facing there was that the code was not being recognized by the RF outlets.

I was finally able to resolve that issue so I just need one GPIO pin to control all my RF remote outlets now!

Troubleshooting my original issue:

I am using this receiver and transmitter - 433MHz Tx-Rx pair (set of 2)

I was using the RCSwitch library ported over to the Raspberry Pi from here
http://ninjablocks.com/blogs/how-to/7506204-adding-433-to-your-raspberry-pi

As mentioned in my previous post, I first tried using the Audacity route but I could not decode the data correctly.

Since I had an Arduino lying around as well, I downloaded the RCSwitch library for the Arduino and tried the advanced receiver demo.

The output for one switch of my remote looked like this:
Protocol: 1

Decimal: 1398209

binary: 000101010101010111000001

PulseLength: 207

I noticed that the pulse length was 207 which is different from the default length in the code. I quickly changed the pulse length in the send demo sketch on the Arduino and was able to get the RF outlet to switch on!

So I went back to my Raspberry Pi and modified the send.cpp code to look like this:

int main(int argc, char *argv[]) {
    /*
     output PIN is hardcoded for testing purposes
     see https://projects.drogon.net/raspberry-pi/wiringpi/pins/
     for pin mapping of the raspberry pi GPIO connector
     */
    int PIN = 0;
    unsigned long code = atoi(argv[1]);

    if (wiringPiSetup () == -1) return 1;
        printf("sending code[%d]\n", code);
        RCSwitch mySwitch = RCSwitch();
        mySwitch.enableTransmit(PIN);
        mySwitch.setPulseLength(207);
        mySwitch.send(code,24);
        return 0;
}

Note: I have removed the header files for a cleaner code look below. Please include them in your actual code if you want to use the code below.



I have the transmitter data pin connected to the Pi pin 11 (GPIO 17). I re-ran make in the dir and sent the previously decoded code:
sudo ./send 1398209

And it works! Good riddance to the multiple GPIO pins to replicate the remote functionality +  the remote is free for use independently now.