I thought to myself, what a great opportunity for me to put together a DIY electronics project that would also be green. I wanted a quick and inexpensive solution so I decided to go with the Arduino as the MCU and build everything from scratch.
This document will document my project from beginning to end.
I had picked up a battery powered LED light that would be great for this project.
I have a bunch of ATMega chips lying around as well as a few Arduino clone boards, so I was well on to my way of building this project with material and parts that are in my parts bins in my shop.
I started to think about what kind of design I wanted and decided to go simple, lean and mean.
I have done some work with latching relays in the past and really like the idea of using the MCU to latch the relay on and off without having to keep constant power on the ATMega ports all of the time.
The chicken coop is located in an area where there is no easy access to AC power and I wanted a battery solution that I could, at a later date, add solar panel access for charging.
First off I had to determine the volts and amp requirements of the LED light.
I took the LED light apart and soldered some wires to the existing switch circuit so I could trigger the light with the relay.
The LED light consumed 6 volts at around 500 milliamps.
D-cell batteries originally powered the LED light. I did not want two different battery sources and I did not want to change batteries all of the time. So I decided on a single battery source to power the MCU and LED light.
Below is image of LED light mounted in Chicken coop, two wires for switch and two wires for power: