I'm building a system which, although compartmentalized, involves connecting ~30digisparks and some various pcb's I've designed. I want it to be as idiot-proof as possible, but also cheap (given the crazy number of connections), and easy to create (ie so easy to solder).
Basically, the meat is a TON of IRleds and receivers in various light-gates. Everything should be 5v, and total power usage will be off battery and should be under 1A. I need at least 4 connections (5v, ground, couple of signals), but more would be nice.
First thought is 1/8 headphone TRRS. Cheap, should be able to cut off ends and solder myself, and not even need to care about breakouts. But not hot-swappable and I worry about shorting things with bad connects/shorts if the power's on.
Other options? RJ45 works, but would need breakouts, as it's fiddly to keep a signal with untwisted wires. Gets more expensive, but still manageable.
Db5? Fiddlier to connect, could likely solder without much difficulty, might be more costly.
"RJ45 works, but would need breakouts, as it's fiddly to keep a signal with untwisted wires. Gets more expensive, but still manageable"
I would go for this Cat5a cable is twisted and provided the current is not large can be quite long. You have not indicated the length required. You can double up the wires for more current.
Do you need positive latches on the plugs? If there's movement or vibration then latches are a really good idea. 0.1" pitch connectors are pretty easy to work with and match to breadboards, Arduino headers and so on. I use the connectors from TE Connectivity in their AMPMODU MTE series. They can go board-to-wire, wire-to-wire and you can get plugs with exactly the number of wires you need (use different plugs for different connections so they can't be mixed up accidentally.) The pins must be crimped with an appropriate crimper, but you don't have to buy the thousand-dollar crimper from TE. A $40 one works.
There shouldn't be any movement at all in 99% of use, and then catastrophic movement if one of the dogs crashes into a gate (it's a timing system). I'll design with very solid strain-relief options, regardless.
I'm leaning more and more towards cat5 rj45. I can fit 4 breakouts on a 2" PCB and print them at seeed, so that's 25c each plus the plug from jameco/mouser whatever, which is a manageable cost. And cat5's cheap like beer from monoprice. I think the soldering will be manageable, even for a novice like me.
I'm liking the idea of having more than enough connectors, so that I can have the outside pins (or whatever) always be power, so if anything gets plugged into a wrong receptacle I just get wonky signal but no power shorts/fried components.
dirtyharry2:
First thought is 1/8 headphone TRRS. Cheap, should be able to cut off ends and solder myself, and not even need to care about breakouts. But not hot-swappable and I worry about shorting things with bad connects/shorts if the power's on.
Thoughts?
I use TRRS in my project.
If you connect V+ to tip, and GND to sleeve, then what you describe about shorting things will never happen. I know because I originally made the wrong connection and figured if connected properly, power supply short will never happen. And yes, it is hot swappable.
The advantage of using audio jack (besides being simpler) is if someone trips on the wire, it will disconnect, and not drag your entire project box down with it like using other more secure connectors.
doughboy:
The advantage of using audio jack (besides being simpler) is if someone trips on the wire, it will disconnect, and not drag your entire project box down with it like using other more secure connectors.
the pin header flying connectors are good for this also as they do not latch.
doughboy:
what is a pin header flying connector? Is it the same as a pre-wired dupont connector?
I was wondering the same thing.
I would not use dupont line for this, it's not rugged enough for use outside of a case except while prototyping. KK-100 connectors are a little better, but I still think RJ-45 or RJ-11 connectors are probably ideal.
You might consider whether phone junction boxes could be repurposed as project boxes. If you need 4 wires or less per termination (ie, RJ11 is suitable), and your electronics are real small, this might be a way to get a cheap project box with built-in connector - and the cables are everywhere, and can often be had for free or near-free as people discard landline telephone gear.
if it is dupont connector, it should be fine. I use them on quadcopter and is subjected to intense vibration and it works just fine. I have not had any incident where it got disconnected. And the ones I used are 3 pins (servo connector) and it held up fine.
The disadvantage is the possibility of inserting the connector in reverse.
your other option is USB connectors. That was my second choice after TRRS connector on my project.
You can get stacked up USB A female connectors.
The advantage of using usb is we all have usb cables laying around.
USB connection is secure enough, but can also release if cable is yanked.
standard usb is 4 wire, but you can go 9 wires on USB 3.0 connectors.
doughboy:
if it is dupont connector, it should be fine. I use them on quadcopter and is subjected to intense vibration and it works just fine. I have not had any incident where it got disconnected. And the ones I used are 3 pins (servo connector) and it held up fine.
The disadvantage is the possibility of inserting the connector in reverse.
I suppose it must be dupont then as i use them on my quadrocopter also.
doughboy:
The disadvantage is the possibility of inserting the connector in reverse.
Not if you use polarising pins.
For lead to lead connection polarised shrouds are also available.
I just examined one, Dupont connectors have square edges
Quad ones fitted to escs have edges slightly rounded but look very similar.
Edit
I stand by my origional post though, provided the plugs are flush or slightly proud of the case so the plug edge does not catch ,they are remarkably robust.