Introduction: AC Light 433 Mhz Radio Controlled Timer With Arduino

About: Computer geek who stumbled upon arduino and electronics in general a while ago.

In this instructable I will document how I made a radio controlled timer for my outdoor flood lights. My lights are of the older type and uses a whole lot of power (150w and 500w lights). For this reason I've barely just used them, but now I've made a timer that is triggered from a small 433 mhz remote control, and keeps the lights on for just two and a half minutes before it turns them off. For now, I've settled with making one timer for each light, since the distance between my lights is rather long.

Warning! This project includes working with high voltage AC power, which might be extremely dangerous if not done properly. Be careful, and only attempt this if you are qualified for the job and have taken the necessary measures to protect yourself.

Step 1: Parts List

I've bought most parts on ebay, but as listings come and go, I won't link to ebay, I'll just list the names of the parts, so you can search for them if you'd like.

  • Adjustable DC buck converter, LM2596 (adjusted to 5v)
  • 2ch Relay board module with optocouplers, 5v
  • 433 mhz PT2262 4 button remote control
  • 433 mhz RX module, with premade external antenna
  • DC 12v power supply
  • Arduino NANO v3 5v
  • A rather big box to mount it all in (bought mine from a local retailer)

I will also use some other parts that most users will already have lying around the house:

  • Soldering iron and solder
  • Shrink tubes
  • Hot glue gun
  • Dupont headers
  • Cables

Step 2: Connection List

I like to test my setup on a breadboard before I solder stuff together as the picture shows, but for convenience I will list the connections as they are in the proper setup, and not as in the test-setup on the breadboard.

From buck converter, using the OUT connections:

  1. V+ to VCC on radio module
  2. V+ to arduino 5v
  3. V+ to VCC relay board
  1. V- to GND on radio module
  2. V- to GND on arduino
  3. V- to GND on relay module

Other connections:

  1. Relay ch1+ch2 to arduino D6
  2. DATA on RX to arduino D2 (interrupt 0) (the radio module has two DATA pins, either one can be used)

I will not list the AC connections here, as the pictures and diagram show them, and they really are self-explanatory.

I drew a simple diagram that shows all connections.

Step 3: Software

There are plenty of tutorials and instructions on how to map your remote control button codes, and I will not go into detail on that here. I believe I've taken a rather simple approach to the decoding, but as I live in the woods with over a 100 meter to the next neighbor, this works fine for me.

I use the RC-switch library which can be downloaded here: RC-switch @ github

There is a few demo-sketches there if you'd like to play around.

The sketch for this project can be found in the attached .ino-file.

I'd recommend uploading the sketch and testing on a breadboard before you solder the project together.

Step 4: Soldering It All Together

I won't go into detail on how to solder, and I am by no means any expert myself. I use silicone cables for the DC connections, and bigger, more rigid cables for the AC connections. For ease I use color coded cables, red is 5v, black is GND, and the white cables are for the digital connections to the arduino. I also use shrink tubing to help protect the connections and prevent shorts.

A helping hand is very useful at this stage.

Connect it all, and if you'd like you can test it the circuit now before you insert it into the enclosure by connecting the 12v power supply to an AC power source.

Step 5: Mounting It All in a Box

I mostly use a hot glue gun to mount the pieces of the circuit in a plastic enclosure, where I've also drilled holes for the incoming and outgoing AC cables. I've also used a screw to ensure that the rather heavy 12v power supply stays in place. The box is now ready to be installed and used.