LED Lighthouse Keeper; DIY Christmas Gift with DIY Retail Packaging
Posted in Projects, Software Libraries, Tutorials by Bill
21 Dec 2010

Nothing means more to someone then a gift that took more time to make than money to buy. This is an example of such a gift. Set your way-back-when machines to 2002. Getting ready to finish high school, I had built up some hacker level of electronic knowledge. My parents; both nautical people; have a large lighthouse fountain in their backyard. My mother’s only wish for Christmas that year was for me to build something that would illuminate the lighthouse as if it were a functioning beacon. I obliged, with a circuit consisting of a 555 timer and a 4017 decade counter. It resulted in a simple device that did the job.
Not actual fountain, but close
The old LED board
Fast forward 8 years. I’m out of college with an EE degree working for the US Navy building robots. My mother’s wish this year? To replace the aging and failing lighthouse circuit. Well, I can’t just resort to cheap protoboard again. I wanted to show here all that money for college was well spent.
Enter the LED Lighthouse Keeper. A day’s worth of design and programming, with (hopefully) impressive results.
The new design
The design is simple. Four groups of Red/White LED pairs (the lighthouse has four windows at the top), a super-bright blue LED to illuminate the lower windows, a LED driver circuit and an ATtiny85 to create a realistic circulating fade effect. The LED driver is for the Luxeon Rebel LED, which can draw a few Watts!!
Schematic (Click for full)
Not the most elegant solution to everyone I’m sure, but for the few bucks an ATtiny costs, it got the job done. I did run into some issues with glitches in hardware generated PWM, but I wrote a Band-Aid fix. I could have just done software PWM, because the ATtiny85 isn’t doing anything else (like monitoring electrical mains) but in the end I just finished what I had started with hardware.
The PCB had to be carefully designed to dissipate heat away from the blue LED. If you look at the picture below, you can see the polygon in the middle whose sole purpose is to draw heat away from the LED.
Board Design
Video demonstration
UPDATED: A video of it installed
Now here’s the kicker. How to present such a gift? I thought it would be cool to create my own DIY cheesy retail packaging as well, demo button and all. I enlisted the help of my talented girlfriend to design the graphics, and she did a great job. I added a demo circuit, which is just a pushbutton switch and a 9V battery, but the effect is awesome. This really does look like something you would pick up at a store, yet is a custom made gift. I hope she likes it.
The source code is available for Download Here.
Some more photos. All photos can be enlarged by clicking on them.
Printed out the design, created in PhotoShop
Gluing design to box. We also cut out a hole, and glued clear plastic on the demo window from inside.
Demo circuit with 9V battery
Added some padding on the inside
Top view
Side
Back
Installed
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
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14 Comments.
Unbelievable!!! You never cease to amaze me! Wonderful present, I’m sure your folks will love it! Merry Christmas!
Aww, Thanks Ro-Bot-X. Your projects are as amazing to me!
I’m absolutely going to use the ‘make your own packaging’ bit for all my gift projects from now on. So simple, yet so classy.
[…] Christmas [Bill Porter] decided to show his parents that those college dollars were well spent. He upgraded the custom lighthouse light which he originally designed in high school for their garden fountain. He even went so far as to […]
So how did you resolve the PWM glitch? Where is the source code?
thanks,
jb
No, I never did find the source of the glitch. I devised a bandaid to get around it however. Basically, I leave the pin un-attached (in input mode) while enabling PWM, wait a few, then attach the pin as output. This ‘skips’ the start-up glitch.
I’m on travel for the holidays, but I’ll post the code when I get back.
[…] lighthouse – [Link] Tags: ATtiny85, Led, lighthouse, PWM Filed in Led | 1 views No Comments […]
Re: The Glitch. Check this out
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&p=769479&highlight=#769479
I’m guessing its the issue you were having. Drove me nuts too…
Paul,
Lol, one of the posts on your thread was a link to my thread. Small world.
Hmm, I’ll have to try your fix when I get back from the holidays. Thanks for posting it.
Source Code added to post.
Very Nice Bill! Great job on the effects!!
I have not yet checked out the code, but i hope to learn from it. I am attempting something for my bicycle that may be able to benefit from your project.
The box was tops man! Mom should be very happy!
-fab
Very cool mod! The effect of the lights is impressive.
-vic
Thanks Victor!
Could you send me the ready .hex file, as i don`t have the possibility to make a hex from the source code.
Thank you a lot!
Mikel