3 blog posts already, amazing – though very shortly I may have to start talking about far less interesting projects, or post less frequently. This is starting to take quite a bit of time, and I’m running out of interesting things I’ve been doing. :)
So, recently I’ve started looking into ASIC design – it’s will still be quite a long time before I can practically start thinking about trying to design my own chip, however, in the meantime some chip reverse engineering has attracted my attention.
Now, I mostly operate from a home-lab environment, and it’s not really safe to involve things like… high concentrations of Nitric acid. But, having recently acquired a decent cheap USB microscope (the Veho VMS004DELUXE USB Powered Microscope
May 2010
Project: 8×8 LED Matrix Controller
Another week has gone by, and it’s time for another project!
This week’s project is a little bit more complex than the last one, but it’s still pretty small. It’s a small board that drives an 8×8 LED matrix. It’s actually a pretty silly project because I only have a dozen or so of these LED Matrices around (I’m not sure I can even buy these specific matrices anymore) – I actually bought them back in 2005 – they’re 8×8 arrays of red/green LEDs. They’re organized with a common anode per row, and then red/green cathodes per column. (Davr also got some, and has a number of entries on his blog about his efforts)
Just for fun, I set out to design a board that would sit on the back of the LED matrix and make it easy to drive from a small microcontroller. My design goals were to have current drivers on the common anodes, and provide a shift register to easily configure the other LEDs. I also wanted to be able to easily chain multiple boards together to make a much longer array. (Read on for more details about the design…) (more…)
Here’s the first installment of my weekly project report thing :) Wish me luck!
So, not terribly long ago I decided it was really time to give microcontrollers another go; My history with microcontrollers in general has been a little sketchy, because not only are they pretty limited systems, but they don’t really allow a lot of creativity in solving your problems. Being mostly self-taught on ARM and x86 CPU architectures, the little 8-bit uCs generally seemed more like a pain than anything else.
However, I was determined not to let my history deter me, and to try again. I ordered some AVR DIP chips for prototyping and a serial programming cable. Unforuntately, like so many well laid out plans, this didn’t wind up working out – not knowing too much about the AVR landscape, I had inadvertently ordered a serial programmer that requires an actual native serial port to work (it wouldn’t do anything with my USB-serial converter… And seriously, who has a native serial port around these days?)
Being incredibly stubborn and unwilling to wait further to order yet another programmer, I decided to take matters into my own hands – After reading the AVR documentation on programming their chips (which is actually quite good), I put together a small CPLD based programmer which has served my needs. Read on for the full details…
I’ve decided that every weekend (starting next weekend) I’ll update this blog and detail one of my projects; I’ll either write up something that I’ve already completed, something that’s in progress, or something that I’m planning to do in the near future.
If nothing else it could be interesting to follow, and will serve as somewhat of a historical record of what I’ve been up to.
I’m a little worried at this point about running out of content, but I do have a bundle of little projects that I’ve completed in the recent past that I can write up, for the first several weeks. Hopefully I have something further by the time I’m done with those… :)
Most likely I won’t take the effort to provide project design files or documentation, but if there’s interest I can probably make that sort of thing available – These are mostly just hacky personal projects after all (though, at least a few of them have larger intended audiences).
(Small update: Apparently comments were broken, but they’ve been fixed now)