Picture of Bird cage LED daylight simulation system

Sometimes you get a chance to combine helping out your family with a nice hobby project..

In this case my father in law was looking for a lighting system for his bird breeding cages. A daylight simulation system to be exact. He asked me to take a look at a website which sells such systems, since he wanted to know what he needed to order. After a quick look at those websites and seeing their pricing.. I convinced my father in-law I would develop and install the system myself.. He would get his lighting, I would have a new hobby project!


Daylight-simulation systems

The requirements for a daylight simulation system are simple: lights should gradually (say in 20 minutes) increase to a set high intensity in the morning, stay at that intensity during the day, gradually decrease to a set lower intensity in the evening, and stay at the low intensity during the night.

Other 'non-functional' requirements of such systems: the light should not flicker (this is stressful for the birds), the dimming should be smooth (again related to stress), the system should be reliable..

This instructable describes how I built this system based on an Arduino, some N-channel NPN transistors, a real time clock, a character LCD and some cheap LEDs from eBay.

A sidenote: The birds are only in the cages for breeding, the remainder of the year they are in an outside bird sanctuary. So no animals were harmed for making this instructable!

I've submitted this project to the 
123D Circuits Contest and the 2014 makerlympics (both pending approval). So if you like this project: please vote for it! Thanks!

ercan14419 months ago

Hi, this is really a great project for my birds!

But could you please post a little more detail on how to wire-up the whole thing together as this is not really clear right now.

Also what's the value of used resistors and capacitors, and again how should I wire the whole thing together? Of course a PCB layout would be perfect, but if not, an electrical wiring overview would be sufficient.

dogdog1 year ago

Great project, but what are "N-channel NPN transistors"?

eagle is easy to use to design a pcs and itead studio is good to order

carlos66ba1 year ago

It is a nice build and nice program. I am worried about the use of the power transistor. It has a beta of only ~25, so if you limit the arduino output to 20 mA this gives a maximum Ic of only 0.5 A. An enhancement mode MOSFET (e.g.,

IRF540N) is able to drive a current to its limit (33 A for that one!) without loading the arduino.

pbronneberg (author)  carlos66ba1 year ago
Hi Carlos,

Thanks for the comment!

You're right about the transistor. Based on the spec I figured I should be able to get 1A out of it.. fortunately I decided to stay well under this level by using multiple transistors and divide the LEDs in groups (each group driven by a separate transistor.). Your comment indicates the expected Ic is half of what I expected... That must explain the slight drop in brightness I see when powering all cages..

I actually ordered the IRF540N & IRF3205 transistors for this project.. unfortunately the delivery was severely delayed (that's what happens if you order cheap parts via eBay) so I used some basic transistors I had in stock...

This comment is exactly the type I was hoping for, so I will have to convince my father-in-law to temporarily shut down the system so I can replace the transistors.

Hello there! I do not think you need to shutdown the system. Worst that can happen is you either fry one of the BD transistors or even the arduino IC. Both are easy and cheap to replace so don't worry too much!!! When the MOSFETs come you can replace the BD's (or maybe not at all and see what happens, interesting experiment!).

I also buy these type of components on ebay, takes usually 1 month to get here from China, but you can't beat the prices! Always buy 2x than you want so you build a stock of parts :)

Anyway, this discussion came in handy because I had someone just asking me 2 days ago about doing PWM on a 20A, 12 V DC motor and I had recommended the IRF540Ns...