I picked up a bigger breadboard at Fry’s, along with a few logic chips to play around with while waiting for my shipment from Mouser to come in. When I got home and started setting things up, I realized that the only way to get 5V power to my breadboard was through jumpers from my Arduino’s 5V and Gnd pins, which isn’t going to work if this project is going anywhere. It was late and I was impatient, so I decided to improvise. I keep a giant bag of old phone chargers and USB cables stashed away just in case, and I rememebered that USB wall chargers put out 5V, even up to 2A sometimes. I said fuck it and got to work.

I recall from my XDA-Developers days how people used to praise BlackBerry USB cables for their thick conductors and reliablility. I needed to be able to solder or crimp onto the power lines of the USB cable to get some kind of connector working, so a BlackBerry cable seemed like the best choice. Upon snipping the micro USB tip off and slicing down the insulation, I was greeted with a mess of wire strand shards all over my desk, which will probably end up stuck in my feet later. It seems that the cable was shielded pretty well. The power conductors ended up being very, very thin, and mostly consisted of some synthetic fibers inside the insulation, perhaps for strain relief. I was already this far in, so I stripped back some wire, cut up a breadboard jumper, and attempted to splice the two together. It actually ended up working, but god what an ugly cable.

I could not imagine this new piece of crap being nearly as reliable as the original cable, so I tried to see what else I could find. I came across the wall adapter for an old active USB hub that I don’t use anymore and was pleased to see that it put out 5V at a nice 3A max or so. The cables were super thick and there were no extra cables, or shielding to get in the way. I cut the plug off the end and was presented with two nice, strong, shiny copper wires. The wires ended up being too big to stick into a breadboard, so I got some heatshrink and snapped off two header pins and soldered it all together. This one ended up looking much better, but I did have trouble keeping in the breadboard. I also didn’t like having those two conductors right next to each other, soldered ono the header pins. I could see that shorting out at some point.

Anyway, fucking up those cables took long enough to where I didn’t get to mess with any of my new ICs that night, and so I just drove to Fry’s in the morning to find something better. Most of the universal, adjustable DC adapters were at least $20, which I wasn’t looking to pay right now. In the prototyping section, I did come across something like my hacked-together USB cable thing, but done correctly. This cable has a male USB A connector on one end, and a DC barrel jack on the other. Nice! I think this cable was about $3.00.

I still needed a female connector to get the power to the board though. I couldn’t find any jacks that would fit on a PCB, but in that same prototyping section, they had a female DC jack with a two pin “JST” connector on the end, like you might see on a computer fan or sensor cable. I couldn’t find any female JST connectors in the store, but I thought I could maybe fit two right-angle header pins in there and stick that in the breadboard.

This ended up working very well. The connection is loose, but that’s nothing some tape can’t fix for now. I finally have some reliable power from the wall. Total cost of power stuff was about $6.00 I think. I now see that I could have gotten a 5V wall charger and a proper connector online for less than $5, but instant gratification is a bitch, and I lose all patience as soon as I get really excited about a project.

I think this should do the job while I’m prototyping on the breadboard, and I’ll be ordering a proper barrel jack to solder in when I move to PCB. If the USB cable in the phone charger isn’t providing enough current when the project is further along, I’ll get a male tip for the USB hub charger to get that sweet 3A.