Evil Mad Scientist Laboratories received an email from someone who wanted to hack their Peggy kit. This LED matrix kit has been featured on Hack a Day in the past, and provides hardware to set up a 625 LED matrix.
This user built an external array of LEDs that they wanted to drive with the Peggy hardware. There are a few options for making this happen. The first one is to run wires from each of the 625 LED footprints on the board. Each has an anode and cathode, so that makes for a total of 1250 wires to run. It turns out that people have actually done this with the Peggy in the past, using very fine wire.
EMSL suggests wiring the rows and columns instead. This way, only one wire is needed for each row and column, allowing a 25×25 LED grid to use 50 wires instead of 1250. They also explain how to expand the grid to a 30×20 LED matrix. It’s a good explanation of how the kit works, and how it can be expanded.
Photo [oskay]
To be honest, I can’t believe people would be crazy enough to wire 1250 links without checking the schematic/PCB routing to see if there was an easier way! (2500 solder points could get quite tedious after the first couple of hundred)
It’s an amazing result if you succeed but, given the number of wires, it opens up a lot of scope for getting something wrong.
arduino people would
ROFL
“While *ahem* labor intensive, this method does work. We know this partly because several people have actually done it.”
http://makezineblog.files.wordpress.com/2012/02/peggy2.jpg
SEVERAL people! I was pretty sure that someone could go the hard way, but SEVERAL!
Wow, All the little wires, i’m getting a migraine just looking at it
There are very very few people who are extremely talented artists AND electrical engineers.
If you’re solidly one of the latter types (and oblivious what it means to be the former type), mocking “users” and “Arduino people” for going about it the wrong way is probably the least graceful reaction.
The better reaction is to have offered something informative about the better way of doing things.
The community hasn’t. Fortunately EMSL have (if belatedly, although EMSL can’t be faulted… it’s an open project that does what it should, and usually unsupported tweaks are community contributed).
If you guys see any value at all in non-EE types dipping their toes in DIY, and if you lament the decline of interest in EE… then don’t be an ass.
lol