Making physical connections to the Arduino board

What does everyone use for connecting circuits to the Arduino? Does anyone have any better suggestions than sticking wires into the sockets on the board?

I've got a circuit that is going to be mounted in a case and I'd like to make a semi-permanent connection to the various in/out pins. I don't want to solder direct to the Arduino as I want to be able to disconnect it if required, but stuffing wires into the blocks is error prone and likely to come out (I'm going to be using most of the external pins). I'm also using multi-core wire which doesn't go into the pins very well.

I'm connecting to some external boards / devices, but a shield is a bit extravagant for what I'm wanting to do.

I have tried some "2.54mm 0.1in. Pin Strip" - but I am having a problem soldering to it cleanly. The only other way I can think of is to try using the pin strip and then putting a PCB header socket but that means having 2 connectors and is likely to be bulky although not such a big problem with this particular project - has anyone tried that?

Thanks

-- PenguinTutor

I made a bunch ( a whole lot) of "patch cables"

I bought some of these pin headers

http://mikmo.dk/misc/pins.jpg

They snap apart and then i soldrede hookup wire to one end and reinforced the solderjopint with heat shrink.

If you want to use them with a bread board you can solder a pin header to both ends of the wire.

After i made all my patchcables i saw seeedstudio has these:

http://www.seeedstudio.com/depot/breadborad-jumper-wire-70pcs-pack-p-234.html?cPath=34

If i had seen them first, i would have spend the 5$ + shipping to save the time i spend making my own :-)

When I have done something like you are talking about I have made a shield out of protoboard (sorry no pictures) but you have to be ingenious with connecting up the oddly spaced digital pins (I bent the header pins I was using).

Or I have soldered to 2.54mm (.1") headers with heatshrink on each wire but as you say, it can be a bit fiddly. If you haven't already then I would suggest investing in a 'third hard' which are a great help for soldering fiddly things like that.

Mowcius

I took some headers and some old IDE cables and made connector cables. Helps keep things looking more professional IMO.

For quick proto set-ups I've been using: http://www.seeedstudio.com/depot/electronic-brick-shield-v4-p-458.html?cPath=48_49

That allows standard .1" spaced female plugs and there are lots of extra ground and +5vdc pins avalible. Nice sale price right now.

Lefty

I made these for using with my bread board. I have two eight pin, and two six pin cables. Just right for the Arduino. I scavenged the ribbon cable from an old 40 wire IDE disc drive cable. Then I used the same header material for my sixteen pin LCD.

These are nice. I bought several of the V1.0 boards when they were closed out at $2 apiece. The V2.0 is not quite as good a bargain, but still okay. You can solder permanent connections to the board, and (un)plug them easily without scrambling connections. Think of them as "Arduino plugs" ;)

Thanks for all the suggestions.

MikMo - those pins are the same as I was trying to explain, I wasn't able to link to a photo as this is my first post to the forum as this is my first Arduino project (in fact first time with a soldering iron for a few years - although I have created quite a few electronic projects it's been a long time).

The problem is getting the wires soldered on, even with a helping-hand holding the wires the gap between the solder joints is very close and joint does not feel secure. Also the gap between the pins on the Arduino is very annoying meaning I have to bend pins or have a 6 and a 2.

The patch cables are great for connecting to a breadboard, but I was hoping to have it as a single connection to make it less likely to plug a wire to the wrong pin.

mowcius I did think about making my own shield, but as you say fiddly. I'm wanting to connect to several different "modules" (circuits) and I want to be able to connect them up separately. Which I could do by adding connectors to the home made shield.

retrolefty - that looks really useful. I may need to look for a supplier in the UK though to keep shipping cost low - definitely worth considering though.

Thanks everyone for all your suggestions - some great ideas here to get me thinking....

-- PenguinTutor http://www.penguintutor.com

The problem is getting the wires soldered on, even with a helping-hand holding the wires the gap between the solder joints is very close and joint does not feel secure.

The gap only feels small because you're out of practice, but your instincts about the connections not being very secure is right. That kind of connection is really bad for "real-world" use, where you need strain relief and the ability to grip the connector, not the wire.

But, for building a project where the connection will be more-or-less permanent, and the parts are mechanically connected so there's no great strain on the wires, they're fine. Similarly, for hobby uses where you won't be doing a lot of (dis)connecting, there's a reasonable trade-off between the much lower cost and needing to take a little extra care.

If you want to improve strength, you could use small pieces of stripboard or protoboard, and solder both header pins and the wire to them. That would give you the equivalent of a "connector shell" to grab, and the option of adding strain relief by using a larger piece of board and gluing the wires down.

Ran

To help ensure my connections stay secure i use heat shrink around them. I use 1/2" around the header and inside that i have the next size down going over a biut of the wire and to the top of the plastic piece of the header.

As my temperature logger is coming together, this topic is very timely. I’ve collected several Futurlec mini-boards (realtime clock, logic level shifter, SD Card). All have both male and female 0.1 O-C headers.

At the breadboard stage there’s a lot of spaghetti to connect these to each other & to the Duemilanove. I’ll try ribbon cable from Adafruit protoshield to LCD, but what about all these others? Previous posts are helpful, but wondering if anyone’s used any of the following or can recommend similar stuff. Might go w/ Futurlec but ship time is 2-3 weeks.

futurlec.com/Connectors/HDCONNS5.shtml
www.molex.com/molex/products/group?key=wire_to_board_connectors&channel=PRODUCTS&langPref=english
www.bgmicro.com/index.asp?PageAction=VIEWPROD&ProdID=12868

Thanks!

For a permenant project I would de-solder the headers off those boards and do it with ribbon cable. It's only LCDs that I hate connecting up with permenant cable.

Mowcius

Get a screwshield http://wingshieldindustries.com/products/screwshield/

Get a screwshield
ScrewShield for Arduino « WingShield Industries

Not the cheapest thing but they are a good idea. Not great for permenant projects, more for when you have a complicated wired prototype, and you want to play with your arduino doing something else, but not loose all the wiring.

Mowcius

Depends on your soldering skills. If you have good skills, then some of the other ideas are good. If you don't, then a screwshield is a really excellent way to get a neat, reliable set of connections to an Arduino.

I wouldn't use it for a permanent installation, but I can solder pretty well. I'd probably pick up another RBBB kit, drop off the pins and solder wires to whatever I needed.

But if the OP has limited soldering skills, then the screwshield is going to make a much neater and reliable way to construct his project.

'course if you get the screwshield as a kit, you have to solder it together, but the skill level is pretty low for that job.

Thanks for the suggestions. Soldering direct to the Arduino is not an option as I want to keep it modular and be able to swap the Arduino out if necessary.

Shields are good, but expensive and more than I really need.

I've now got some right-angle headers which appear to do the job http://www.penguintutor.com/blog/viewblog.php?blog=3062

-- PenguinTutor

If you expect this to be a something fairly “permanent”, with maybe only the occasional change done (software upgrade, etc), you might want to look into purchasing pre-bootloaded ATMega8/168/328 chip(s), 28-pin DIP socket(s), the necessary capacitors and resonators, and build the circuit on a protoboard (or etch and drill your own custom PCB). Solder a socket to the board, then install the microcontroller into the socket; when you need to change it, remove it from the socket, mount it in an Arduino in place of the Arduino’s regular CPU, program it, then swap it back.

Another option would be to build a ZIF programmer onto a protoboard shield for pre-bootloaded ATMegas (basically, all the pins for programming the Arduino, with the exception of the clock/resonator pins, are brought up via the shield pins, so - in theory - if you remove the CPU from the Arduino, then mount a ZIF socket to a protoboard shield, wire the pins up properly to the headers, then add the resonator circuit, and put the CPU in the ZIF socket and then mount the protoboard shield to the “brainless” Arduino - you should be able to program the Arduino in the ZIF socket just like it was in the normal socket).

You could also integrate an RBBB (Really Bare Bones Board) into your interface, instead of using an entire Arduino (kinda a step between an Arduino and a custom ATMega8/168/328 CPU setup).

Even better, add header pins connected to the proper pins (TX/RX, etc) and buy an FTDI cable, and you can make the device “field programmable”.

With all of that said, I am not necessarily sure you even need to worry about the wires working loose; there was a guy on these forums who hooked his Arduino up to his combine harvester (!) as his first Arduino project (!!) to use the Arduino to steer the combine (via a hydraulic servo control) on straight paths in his fields (!!!) using GPS. He mounted his Arduino on a board, which was inside a snap-lid plastic container bolted to the front/side of the tractor. The wires were just fitted in the sockets; I don’t even think he dropped some hot glue on them. He said he never had a problem with them vibrating loose on the tractor for the entire harvesting season.

Maybe you should worry, maybe you shouldn’t. Hot gluing the wires on the board may help. Otherwise, think about another option like the RBBB or a custom socketed CPU…

:slight_smile:

Following-up to my post of a couple weeks ago, to report my solution. Using Adafruit protoshield to which I soldered an IDC 2-row header. A length of 14-conductor ribbon cable goes in a female IDC connector (pressed closed in a vise), and then individual wires of the ribbon soldered to tie points on the LCD PCB. All as shown on pix. The female ICD connector you can get from Digikey, part # S9319-ND. The male headers are on 0.1" centers x & y. I had some from a local electronics store, but I'm sure Digikey has 'em just [sorry] don't have p/n. Thanks for all the advice, guys!

This maybe to little to late, but if you get the 'Wingshield' http://www.adafruit.com/index.php?main_page=product_info&cPath=17_21&products_id=196&zenid=aa7273e8d698d40eb6eb6264113cbf3a you should be able to solder everything upside down on the board and the board would look inwards instead of outwards. It has screw terminals for all the pins and the screws are on top. Just turn the board upside down and solder so the headers and terminals are up.