On the 9th of November 2013 I already wrote about switching the pumps of my Aeroponic plant (chili + coffee) setup through 433mhz.

In the mean time I bought a 433mhz usb transceiver from RfxCom which already supports a huge amount of protocols of 433mhz devices which you can buy in the store. The temperature sensors for example are supported out of the box and I also the 230 volt switches which I wanted to use to switch the pumps are compatible.

So last weekend I finally managed to spend some time on adding my pump timer to my home automation setup. It has been running on one of these mechanical timers with a round disk where you can set a little switch ( 15 minute intervals ).

I had the mechanical switch configured to run for 15 minutes ( minimum ) every hour and to be off in the evenings. The pumps, and also the bubbling water, make some noise and although this is a nice and peaceful sound, it disturbs when watching tv.

For the future, the idea is to have a web based scheduler where we can reschedule and configure for example living room temperatures that would require a smaller interval or a longer watering period.

For now, I’m sending switch messages to RabbitMQ (also running on the pi). I also have an RFXCom module that is subscribed to this queue and deals with sending the actual signal. This is still a bit of a hack as I’m posting messages directly to the queue instead of an exchange.


...
// Wait for connection to become established.
connection.on('ready', function () {
  //set interval to switch on to 10 minutes
  setInterval( function() {
    //send message on to the queue
    connection.publish('rfxcom-send-events', mesOn);

    //And switch off again after 30 seconds
    setTimeout(function(){
        //send message off to the queue
        connection.publish('rfxcom-send-events', mesOff);
    },30000);
  }, 600000);
});


So instead of running 15 mins every hour, I now provide the plants with a 30 second soak every 10 minutes. Lets see if they still look happy after a week.