Comment by snazz
8 years ago
As much as I enjoy quickly building circuits on a breadboard like in many of the photos, they’re hell to debug, because there’s so much that can go subtly wrong. It’s much easier with digital than analog circuits, of course, but it still can be crazy hard to logic-probe every connection to get it all to work. I have spent far too much time fixing little bugs in breadboarded circuits. The toughest issue I encountered was when someone melted through part of a big, expensive breadboard with a soldering iron and it caused shorts on the other side of the board. I couldn’t even trust that the holes that were supposed to be connected were in that case, and I sure wasn’t going to copy over the project onto a new breadboard.
However, I’m not sure if there is an easier way to get quickly prototype electronics. Opting for more ICs and a lower BoM count helps, because there’s less wiring to do in the first place.
I would argue that with the extremely low cost of PCB manufacturing (and... if you have access to it... assembly) it's easier now to just lay out a PCB and get it made. The trick is to build up a library of circuit "modules" (like... power supply section, battery charging, video output, etc) that get copy-pasted together. Of course there's the delay in waiting for the PCBs, which could be frustrating for a hobby project (I was lucky enough to live in SZ for a while where getting PCBs back 2 days after ordering is standard). But parallelising projects can be an effective way of dealing with that, and the variety on working on different things (and the joy of getting a PCB in the mail) can help to mitigate that.
I totally agree. The reason I stuck to DIP ICs was because I could fit them into breadboards and I thought that was easier than any alternative. I was incredibly lucky on how all the breadboards were functional. And there were a few times where I would accidentally disconnect a wire and spend the next 2 hours trying to figure out what was wrong. All this without having a logic analyser and not even an oscilloscope until much later in the build (they are not that cheap). And yes the project sure is complex, too complex, but I guess I was lucky, and I'm glad it's working :).
I had a few interesting experiences breadboarding for a project of my own, for a 6502-based project. Most notable were:
- Being able to detect noise from the system clock crystal oscillator all cross the breadboard (using my oscilloscope)
- Seeing certain I/O pins float to a bit too high of a voltage, when they were supposed to be "low", probably due to breadboard capacitance
- Accidentally making an AM radio when I forgot to connect a wire on an LM386 I was testing as an audio amplifier
Things got a lot cleaner when I went to a PCB, but I did make it all work on breadboards first.
FYI: saelae makes an affordable logic probe. chinese clones are available for ~$10 and usually work with saelae's official software or with sigrok. a logic analyzer is really a game-changing tool.
More power to you for being patient enough to fight through! I’m nowhere near that good.
I'm really not that special, don't sell yourself short.
And thanks :)
Copper tape on cardboard.
Cardboard is a fantastic material. You can draw the schematic on, and then run copper tape along the schematic. It's easy to annotate, since you just need to use a pen. It's able to handle much more current than a breadboard, since the copper tape has a lot more metal than thin wires. You can solder directly to it, and with tape (or some other insulating material) you can cross wires without having them short.
You can also work with SMT ICs. Using a pair of scissors, you can make your own pads and solder to them. I connected an SO8 to read off the SPI data using copper tape. I built an amplifier using a spare Novena amplifier IC on cardboard with copper tape. And I have a level shifter done on cardboard with copper tape.
Bunnie has a good article on it here, including an example power regulator that's handling 2A on cardboard: https://www.bunniestudios.com/blog/?p=5259
When I was a lad, wirewrap was the thing. You can prototype quickly, and make changes easily too.
(It seems like it's still a thing in fact http://www.nutsvolts.com/magazine/article/wire_wrap_is_alive...)
For those interested in working with wire wrap: ebay/aliexpress/whatnot all sell old-new-stock wire wrap wire and the manual wrapping tools. Wire wrap works perfectly on standard headers, but the extra-long headers you sometimes see on arduino shields and such give you a couple more connections per pin: 5 vs 3 if I recall correctly.
It's a really nice way to work, you solder your components onto one of those pcbs with a lot of holes, solder the pins next to em, and from that point on you can wire, unwire, and rewire to your hearts content. Its great to easily be able to undo a connection when you make a mistake.
I would love to try this at some point: http://cpuville.com/Projects/Z80-wire-wrap/Z80-wire-wrap-hom...
Learned this technique in uni ca. 2004 and still use it for hobby stuff. It's nice to have a more stable, noncommittal method!