In the spirit of the matrix sanitizer, here's a similar board that solves a slightly different problem: those bi-color LED matrices that have three rows of pins are impossible to insert into a breadboard. So we need something to make it two rows of pins.
Since selling just the PCB would be pretty weird (you can just order it from @oshpark yourself, and it would be cheaper, considering the shipping), I ordered a whole bunch of those 20mm matrices from the usual sources. Unfortunately, when the package arrived today, I had a bit of a surprise:
I'm holding a 20x20mm, 1.9mm per LED, 788AS matrix. In the box is what came instead: 32x32mm, 3mm per LED, 1088AS matrices. I'm pretty sure that is a mistake on their part, since those matrices are much more expensive, but it's still very annoying.
Now I have several options. I can negotiate with the seller, and maybe they will replace them — then I'm back to my original plan. I can make a bigger version of the matrix sanitizer and sell that — but those bigger matrices don't fit the breadboards as well as the small ones do. Or I could come up with some other project that utilizes those matrices, possibly a lot of them all at once. For now I let the seller know and we will see where that goes.
Have you ever used one of those tiny 8x8 LED matrices? Have you noticed anything peculiar about their pinout? Here's something to refresh your memory:
Not only it's totally random, without a rhyme or reason, but also the only diagram you have to go by is backwards, giving your pin numbers in reference to physical locations of the LEDs, instead of giving your physical locations of the pins in reference to row and column numbers. Sure, you can work it out on paper, but it's easy to make a mistake.
But don't worry, we have a technological solution to this obvious problem! Introducing Matrix Sanitizer, which is basically just a tiny little PCB that rearranges the pins for you into a saner configuration!
Thanks to years of research of our best engineers, it does it without any vias, while keeping the same pin spacing, and even lets you insert the male pin headers without soldering (the matrix still needs to be soldered for good electrical contact).
The bottom rows are the anodes, and the top row are the cathodes. The PCB goes flat against the bottom of the matrix, only making it 1.6mm higher. The resulting contraption fits into a prototyping breadboard perfectly, and because it uses regular goldpins in place of those flimsy thin legs, it provides excellent contact.