First time posting here, so first of all sorry if I'm asking a really dumb question that's been answered many times over - I have tried searching through the forum for an answer, but I appreciate I might not have been searching for the right thing...
I have a project finished at the breadboard stage which I am looking to now make into a finished item. It's a very simple project in which an Arduino Nano connects to an LED strip with a single LED moving from left to right and back again, with 3 potentiometers to control speed, brightness and colour of the moving light. It's something used in therapy for people who suffer from PTSD and I'd like to build a few kits to donate to a local health service, but I'm not sure of the best way to box it all up in a usable package. The idea is to have a control box containing the Arduino Nano and the 3 pots which will also house the power input jack, and a separate housing containing the LED strip which will sit on a tripod. There will therefore need to be a cable between the control box and the LED strip housing, but what type of cable to use is what I'm struggling with. The type of strip I am using is a 5V RGB strip with 3 connectors for data, 5V and GND.
My electronics knowledge is at a very basic hobby level in building guitar pedals, so my first thought was to use a TRS cable as this will allow me to wire up the connectors for data, 5V and GND. However I quickly thought that putting 5V on a TRS cable might not be the best idea - although it's not going to harm anyone, it could still cause a shock which I don't want. Am I over thinking that? If not then what would be a suitable cable to use instead between the control box and LED strip housing?
I hope I've explained this well enough, I'd really appreciate any input that anyone can offer and just let me know if I need to clarify anything.
Hi larryd, thanks for the reply! I've attached an image I've put together in Fritzing - I'm not going to win any design awards but hopefully it's clear enough. It's near enough what my actual wiring looks like, I'm using the wires that came attached to the LED strip which is a NeoPixel/WS2812 compatible 30 pixels per metre strip and pushing the ends directly into the breadboard. I'm using Alpha B100K potentiometers as well.
You are correct that there will only ever be a single LED on at any one time, the breadboarded version I've built works exactly as intended so I know I don't need to worry about power consumption.
As for the wiring, I wanted to have a detachable cable rather than hard-wiring it in - I know I could solder #24AWG onto the LED strip itself and run a length to the control box, but as these kits will be used quite frequently I want something that is as low maintenance as possible - if someone accidentally tugs a wire and breaks a connection, I don't want the whole kit to be out of action until I can collect and repair it. That was why I was initially drawn to the TRS cable idea - put sockets into the control box and LED housing and then if a cable breaks, any old headphone cable would do as a replacement but I really don't know if that would be a suitable option or not.
Nyktipolos:
My electronics knowledge is at a very basic hobby level in building guitar pedals, so my first thought was to use a TRS cable as this will allow me to wire up the connectors for data, 5V and GND. However I quickly thought that putting 5V on a TRS cable might not be the best idea - although it's not going to harm anyone, it could still cause a shock which I don't want. Am I over thinking that? If not then what would be a suitable cable to use instead between the control box and LED strip housing?
I've never heard of anyone getting a shock from 5V. Heck, many of us old-timers check batteries by tasting them.
TRS or XLR will work just fine and will add some professional cabling to your package.
I would have said right away no problem with using a TRS cable or other you may have around.
But there is something to be said for using those other kinds of connectors in @larrryd#3.
And I can say consing up your own silicon/paracord cable can make a pretty solution. I have done it myself, different wire but same idea. Cheap easy professional looking.
Also, TRS and XLR have roles already. At the very least, if you do repurpose a certain cabling solution, make sure anything you ever plug into on any kind of device that uses, say, XLR will tolerate seeing the stuff you circuit is feeding. And vice versa.
Like we wouldn't use household AC plug and socket wiring for hooking up loudspeakers. Sooner later someone plugs the speaker into the wall, boom!
Do not power a Nano (or UNO, Pro Mini etc.) via "Vin" or the "barrel jack". The on-board regulator is insufficient to power anything other than the board itself. You want a proper regulated 5 V supply for the LED strip and the Nano, connected to the "5V" pin.
A meter of 30 NeoPixels will draw something like 30 mA even with all pixels turned completely off
