Today I finally got the latest revision of the LED matrix I built a while back.

After removing the $12 MAX7219CWG matrix drivers from the old boards (along with the PIC12F683’s since they’re still good) with hot air, I put together two of the four boards. They’re on the lower right of the attached image. Above them you can just see the 40mAh li-po battery I’m going to use with these necklaces.

On the lower left you can see the remains of the three v0.4 boards I went through trying to figure out what I did wrong on that version. You can see the boiled spot on the second board while I tried to use the hot air gun on the floor at work in the dark…

The latest version of the board is a little more compressed then the earlier version. It has the Sparkfun mini ICSP header on it as well. This isn’t really needed and I probably should have gone with a normal header but oh well.

The reason this version of the board is more compressed is because I was trying to fit a li-po charging circuit on the board along with the rest of the parts. I designed the board to work without those parts for now but so that I can add them later if I want.

I also broke out the two extra GPIO pins for future use. I should probably upgrade the MPU on the thing at some point to allow for more complex visualizations and more features… but I kinda like the idea of pushing the existing chip as far as I can before changing it out for something more powerful…

LED Matrix Necklace work!: