Wiring for permanent installation

Just wondering how people make their wiring on permanent installations nice and tidy?

e.g. a project with several sensors which need 3V and ground, all running back to the arduino.

How to connect all these up? I can think of several solution which are ‘hard’ wired:

Solder all together and insulate
Terminal block
Solder to protoboard

Ideally it would be nice to have then unpluggable, to replace the arduino for example. I’ve not had much luck with crimping dupont connector (they come loose), is it best to solder them?

Important parameters are cable length and visibility, and sensor type (analog/digital...) and polling rate.

In easy environment I favor JST connectors and/or ribbon cable.

Arduino forum tells us to aim for stand-alone AVR's in end products. There's even a page on making and programming a 'duino on a breadboard... but it's not so great a page and it left me hunting for a work-around when my 328P-PU chips didn't ID as 328P-PA that the software expects. I hacked a core file and got it to work but it was a pain.

Nick Gammon has a breadboard duino page but with much better software and directions. It knows a lot of chips, not just the one.


If your Arduino is a Nano or Mini then maybe you just put that in a project but Uno/Mega-form boards, you should keep.

Permanent install, yes solder what you don't use solid connectors for. Use heatshrink tubing to insulate joins, it only takes a little and is professional. You can even get colored heatshrink (pre-cut yet!) to color-code jobs with.

the nicest jobs are when you design a PCB and use that. offers lables for things and it is hard to get more professional looking or beat the quality.

I use DuPont connectors for a lot of the stuff
I use screw terminals for a lot of stuff
and solder for other stuff.

Nothing lasts forever and will fail with abuse, neglect, vibration or moisture.

The JST crimps are too small for my hands to make as secure as DuPont connectors but the locking plugs offers a lot more security in them staying in place.

I think the problem with any crimp is cheap tools. For a professional job, buy a brand name tool, spend the $100 for it from a reputable supplier.

a solder sucker, a portabile iron and solder is not hard to do.

Thanks guys!

Yes I have heatshrinks, soldering equipment and terminal connectors.

DuPont wires always seems to fall to pieces in my hands when crimping myself.

Mainly, it’s all the 3V and GND connections, and making it so the Wemos or components can be unplugged if they go faulty.

Maybe a protoboard or some header strips might be useful.

It's usually the wires and the connections that fail first, not the components themselves.

Heat shrink goes a long way in keeping solder joints from breaking.

It's usually the wires and the connections that fail first, not the components themselves.

Heat shrink goes a long way in keeping solder joints from breaking.

Thanks, I will be sure to use heatshrinks, I have plenty :slight_smile:

The Arduino has female headers. this is wise. you have to work at it to short out things that should not be shorted

modules should have male pins. make female headers for your modules. buy a strip of female headers , a bench vise and a coping saw. saw off what you need, trim the ends with a belt sander. I do this with every module even if I am not sure the module I have is what I need. it takes half the aggravation out of pinning things up.

solder wires to the stubby little pins, hot glue half an inch up, tie wrap the cables together. stress on any one wire will not pull that wire off, and the hot glue prevents short circuits. put a label on each one that is either read from the top, or from one side of the board, so all connectors can be installed properly by anyone with a little common sense

make male headers for the Arduino. same procedure. hot glue unused pins.

pro tip #1: get a copy of freeware Libre office. use the drawing tool to draw your components. I plan to write a tutorial about how to do this in the not too distant future. if you have the same modules I have you should be able to put the modules on a printout of the attached drawing and see only the little L in the center of the mounting holes. ( the Catalex YX-5300 drawing is based on dimensions off the internet, which do not match the reality of the module ). you can move the modules around as you like to fit the board you have to mount it to, to accommodate straight or 90 degree headers, et cetera. you can lay out your design, print it reversed, and use an iron to transfer your design, with mounting holes marked, to:

pro tip #2: you can cut plexiglass or phenolic with a table saw. you can drill and tap either. mark, drill, tap, mount, display the inner workings of your product.

put extra mounting holes on the board for 4-40 & 2-56 nylon standoffs. get the nylon version of a padded clamp, "this clamp is brought to you by the letter P" clamps to constrain the wires and keep stress off the ends, and screw them on top of the standoff.

you get rigid wiring, replaceable modules and Arduinos, and foolproof reassembly, if you don't suffer from malicious fools.

pro tip #3: get wire wrap female headers and make yourself a Proliferator. a small perfboard with 2 parallel rows, 10 pins for power and ground, 2 rows of 8 for I2C. 4 rows of whatever you need for for SPI if you have multiple SPIs. use the little green or blue screw terminal headers for Raw 5 VDC in, Raw 5 VDC out to feed the LCDS without using the Arduino as a fuse, 2 pins for I2C if you have a display separate from the main board.

pro tip #4: those nylon standoffs again. put 4-40 nylon standoffs on your standard issue LCD module. now you can mount it flat on a surface without needing to cut out a hole, or mount it to the front of something from the inside. picture 3 16X2 LCD modules on the left, and 2 20 X 4 modules on the right, of a flat sheet of 1/4" plexiglass. drill and tap one 1/4-20 hole for a camera tripod. bend a sheet of aluminum and drill and tap to mount the LCD panel to your workbench with a C clamp. You have your displays all in one place, all on one plane, handy but not in the way. if you get your act together and take it on the road, put the display on a tripod