Instructables

Valentine's Day Electronic Card

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Picture of Valentine's Day Electronic Card
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I don't have anyone special to give a card to this valentine's day, but that doesn't mean I can't enjoy the merriment. I like themed creating, and holidays always allow you to get creative in the way you enjoy them. 

This year for Valentine's Day, I made a PCB card in the shape of a heart (in case you couldn't tell). It flashes 12 SMD red LEDs using charlieplexing with a ATtiny13a, running off a single CR2032 coin cell battery.

I made this card entirely in 4 hours. That includes coming up with the schematic, drawing, cutting, and etching the board, soldering all the components on, developing the program, programming the microcontroller, and debugging. Fun quick day project!

The original plan was to use the slightly larger attiny85 (it has more memory so you can write a larger function). But for some reason my programmer really didn't like that attiny85, so I reluctantly switched to the 13. With that, I had to truncate some code. ALthough the code wasn't fully developed at that point, so it just meant that I didn't finish writing it. The only thing that I am sad that I left out was the cosine wave function thingy that i started writing. So instead, there are just a few patterns it shows. Also, for some reason that I just can't figure out today, I couldn't get the button to work correctly. So ignore the button.

Here's a video of the card in action
 
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JackANDJude29 days ago

This looks like a fun introduction to SMD soldering.

zwebber16 months ago
Trying to make it but cannot find the code for the programming step?
LostRite (author)  zwebber16 months ago

The code is attached to step 6. See it?

cgrrty7 months ago

Very beautiful
cgrrty7 months ago

Very beautiful
shelley echtle11 months ago
This is amazing but for a bubble head, I couldn't do it. Thanks for sharing on here, tho.
How much solder did that take?
LostRite (author)  FoamboardRC1 year ago
not much, you apply as little as possible to cover the traces. Its just to prevent them from wearing off. And it assures good connections in all the traces. It is optional btw. I don't really pay attention to linear inches of solder used though.
Where did you get your pcb?
LostRite (author)  techtheaterballoon1 year ago
I make them. I buy square FR4 (copper clad fliberglass boards) blanks and etch and cut them myself. I buy the blanks from Tayda electronics.
frenzy1 year ago
very cool!
This is very cool!
This is too cute!
did you enter this in the valentines day coontest? if not you totally should!!
I love it!
Great Work!!