LED Birthday card.

It is a friends birthday tomorrow and like the typical bloke type I forget to get her something special. And its the end of the month with big bills arriving so an extravagant shopping expedition is not possible. So yesterday I had the idea of returning to my childhood solution which was to glue some junk together and blag the ‘I made it specially for you’ excuse :slight_smile:

Because I’m lazy the I used a spare mobile phone charger rated at 5.5 Volts and 800 mA. This way I don’t need regulation components or battery boxes or even batteries. I used a Atmel8 with Arduino boot loader burnt on it because you can buy them for about £1 and I have a box of them for this sort of project. I programmed it in a standard Arduino and then swapped it over to the custom PCB. I also used a bit of code I wrote for a Knight Rider type LED scanner that uses software PWM as there were not enough built in PWM channels for that project. The PCB was milled on my Proxxon MF70 that I recently converted.

So in summary everything on this project was from the junk / spares box!


I am using the free version of Eagle so am limited to about 3 by 4 inches on PCB size. The Proxxon Miller also has a limited area for larger work.


My soldering leaves a lot to be desired, maybe I’ll ask for a good soldering iron for my next birthday :wink:


The bare minimum, A crystal, Reset tied to +ve and the power supply is taken care of as it will be powered from a 5 Volt mobile phone charger wall plug unit.


The layout was a squeeze!

This is the finished gift, should look good hung on a wall or illuminating the inside of a bin :wink:

Nice job.

Anyone should be happy to receive a gift that took so much to put together. Money pales in comparison to what you did here.

Wow! That's impressive! A lovely thought for a birthday card / present. Maybe I'll have to build myself one for my birthday? :) :) :) :) :)

Mouse, this is a pretty awesome gift unless the girl can do the same as you did. So, is this girl married? ;)

So, is this girl married?

Yea, to an awesome friend. :P

Yea, to an awesome friend.

Haha, that's still cool! I'll make my wife one for sure. Do you know of any insulating transparent/translucent jell that I can use to embed the circuit board into (make the shape of a heart :) )

Thats an idea, I was planning on having a simple perspex front but didn't have time. Maybe worth experimenting with bathroom / DIY silicon sealer. I've noticed that most of the clear stuff goes opaque or 'misty' when its set. ;) I'm sure a small heart shaped jelly mould with some grease on it for releasing will finish it off a treat.