I’m not really sure what’s gotten into me lately, but I’ve become very intrigued by the fact that non-professionals like me can build electronic devices that actually do things. Once this new way of thinking has taken over, I’ve noticed all these things that would be cool to build — for instance, as much as I enjoy watching my FPGA bitcoin miner increment its counter, it bugs me how silly it is that it has to be connected to my multi-100W PC in order to function. Also, the FPGA part that I’m using, an Spartan 6 LX15, is quite small compared to what’s available, and I’d like to experiment with something bigger. So what I think would be really cool to have is a “master” board that has a wifi chip, which controls multiple custom-made “worker” mining boards that maybe have dual-LX75’s on them. This isn’t really cost-efficient when you look at it from a bitcoin perspective, but the master board could easily be reusable (think Arduino with wifi shield), and I could start off with a single mining board that has a total part cost of maybe $100, which seems justified by the educational value. An alternative I’ve been considering is to buy a larger + more expensive FPGA dev board, but the more I see about how possible it is to do these things yourself, the more I want to do it myself.
My perception of what “EE” is has been dominated by my experience in the MIT microcontroller lab: in a florescent-lit room, you work with this aging equipment you don’t fully understand, and when told pull parts from these multi-hundred-bin “pick racks” in the corner which are right next to what must be mile-long spools of wire (jk… maybe). The parts in the bins all have obscure codes on them, and to use any of them you need to know what it is and which other obscurely-coded parts you want to pick with it. This notion was reinforced when I landed at Digikey‘s site for the first time — I had to learn what a CSBGA is (chip package type) and what the I vs C at the end of the part number means (for Spartan 6 chips, temperature tolerances), and that didn’t even get me any closer to understanding how to get the part working.
Luckily, I eventually stumbled upon the guys at SparkFun Electronics , who have somehow managed to create a site that is far more pleasant to use. Their pre-selected parts and accompanying tutorials have in some way reconvinced me that it is possible to actually build interesting things yourself without expert guidance every step of the way. Also, just from reading about how the FPGA boards are designed, it seems like there’s a trend to implementing more functions with general-purpose microcontrollers instead of special-purpose hardware, which is much more enticing from a barrier-to-entry perspective, as well as DIY one.
So, what I’m saying, is that I just bought a bunch of stuff from SparkFun and the next set of posts will be about me experimenting with what are probably considered very simple circuits. I have a few ideas for things I’d like to build:
- Simple multimeter that measures voltage, resistance, and capacitance (though probably not very accurately and over a limited range)
- Simple breadboard power supply — nothing too complicated here, but a good chance to learn PCB design
- Wifi board to control my mining Nexys3
- Guitar effects board
- Very simple “logic analyzer” — probably with little more than the ability to tell what voltage levels are being used, and whether the signal on a line is changing.
And more. I’m still trying to figure out exactly how to position this blog: I don’t think the world stands much to gain from me trying to write yet-another-electronics-tutorial, so while I might write about stuff I’m doing with the hope of giving people an idea of what learning electronics can look like, I plan on keeping things pretty brief for now.