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I'm an amateur tinkerer of electronic components, and was wondering if a product like I'm about to describe exists for testing components.

Say you have an arduino pro mini board. You want to access the FTDI pins for flashing, but ultimately are going not to solder those pins to something else. As I know it now, I have to solder header pins to it to connect the FTDI programmer, then I after I'm done with all of that I can use those pins to solder it to whatever it needs to be a part of. But say I just want to program the board without soldering header pins, so I could reuse it in an application where those original pins wouldn't need to be connected. Is there some sort of clamp or something that has a bunch of pogo pins (or whatever) that would make contact with the board, then have exposed pins on the top where I could plug the programmer in? It would be the equivalent of an IC test clip, but for boards with pins.

I can't seem to find it on Google. Does this exist, and if not, why not?!

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  • \$\begingroup\$ You find a fair number of these devices if you do a Google image search for PCB test fixture press jig. Most of what you'll find is intended for moderate volume testing. Nevertheless, if should give you some inspiration if you are designing you own. \$\endgroup\$ – Nick Alexeev Feb 28 '18 at 18:25
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Look for "test fixture" for PCBs. There are plenty of ideas- generally customized to the board you're using them with, so some kind of custom machining is required. There are companies that specialize in making test fixtures for professional use so they'll have clamps and so on. A "fixture" in this context (as opposed to a "jig") holds the work (in this case, the DUT- the device under test) in position. Depending on what equipment you have access to you might use different construction techniques- CNC machined acrylic plastic plates, laser cut acrylic, inexpensive CNC-milled commercially made PCBs or 3D printed parts.

There are generally several layers- see this photo from this web page:

enter image description here

Plus some kind of clamping system. 'Universal' style clamps exist, but in my experience (mostly Asian manufacturing) most jigs are custom made from standard parts for one specific board design, and look more like this:

https://www.pemicro.com/newsletter/experts_corner/2005_11/index.cfm

http://www.quanteklimited.co.uk/mediac/400_0/media/fsjb~cp2~042.jpg

If it looks like there is a lot of work in designing and making the test fixture- there is. The design work in making test fixtures and test programs can easily exceed the work for the board design itself.

For methods applicable to lower quantities and more hobbyist-y applications, consider the methods Sparkfun has disclosed here- using inexpensive PCBs as parts of fixtures.

enter image description here

There are also reasonably priced cables made by Tag-Connect that can be held in place by hand or snapped in place (the kind of with legs). If you design the PCB according to their guidelines they work decently well.

enter image description here

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For a simple PCB it's not too hard to make your own - the precision part requires a spare unpopulated PCB and a pillar drill.

enter image description here

First you need a suitably laid out PCB, with the signals you want to access all available on test pads on the wiring side (the less populated side). It's easiest if the test pads have through holes, and it's good to keep these design rules in mind if you're laying out the PCB. Here, I want to access points T5,6,7,8,9.

enter image description here

Clamp a blank PCB to a 12mm sheet of plastic, and drill (0.6mm or whatever hole size) into the plastic, to locate these holes. You don't have to drill right through. If you're careful, you get to keep the PCB, though there's a risk you have damaged the plating.

Remove the PCB and drill the correct diameter for your pogo pins, right through, using the original pilot holes. This really requires a pillar drill, it's critical these holes are upright. (If you have a mill, you can use the drill file to drill on proper coordinates : even better.) The pogo pins should be a push fit in these holes - if they are too loose, be careful with the superglue and don't tell anybody.

Fit it on a base to protect the wiring underneath, and fashion some guides and clamps to hold the board in the right place. Mine are all round because I have a lathe : careful use of ordinary woodworking tools and scrap plywood is acceptable. Just avoid the wiring-side components when placing supports for the PCB. The base doesn't have to be polished mahogany, unless you're going for a steampunk look for your test fixtures.

Nice big mounting holes on the PCB makes another good PCB design rule, not possible on this crowded board. If you have mounting holes anyway, you can drill for these as well as the pogo pins, mount pillars in them, and fix the PCB to them for testing.

Finished result:

enter image description here

And clamp the board to it for testing.

enter image description here

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    \$\begingroup\$ +1 nice job. What's the PCB do? \$\endgroup\$ – Spehro Pefhany Apr 7 '15 at 14:03
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    \$\begingroup\$ There are so many smart watches around ... this is a dumb watch! It ... tells the time! (Yes I know there should be a colon in the middle, but unless I make my own 7-seg displays, I have to put up with a simple decimal point, or go much bigger than 33mm dia) There's a LED "analog" display version too, waitihg for me to make cases and finish the software. \$\endgroup\$ – Brian Drummond Apr 7 '15 at 23:51
  • \$\begingroup\$ Cool! I figured it was something like that from the need for a trimcap. \$\endgroup\$ – Spehro Pefhany Apr 8 '15 at 3:00
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I have exactly what you want. I bought it direct from China using taobao from within google chrome.

Try searching for "編程 測試 夾子" on Taobao.com - this translates as "Programming test clip".

eg. http://m.intl.taobao.com/detail/detail.html?id=42343856957&spm=a2141.7631730.0.i1

6 pin clamp jig

You can buy using a taobao agent like bhiner.com

I have not seen these anywhere else.

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  • \$\begingroup\$ It's generally not good to link to shopping / auction sites as the content is very likely to change or disappear. \$\endgroup\$ – David Jan 13 '16 at 8:20
  • \$\begingroup\$ Agreed, I'm not sure if this is this kind of question whose answer is very useful after an extended period of time anyway. Available of things fluctuates so much. I updated my answer to be more generic. \$\endgroup\$ – TomKeddie Jan 13 '16 at 23:11
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Sparkfun has several POGO kits and parts for Arduino's and ISP

https://www.sparkfun.com/search/results?term=pogo

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  • \$\begingroup\$ Had to bump this (and comment -- why do people downvote without commenting why??). I've looked high and low for a pogo plug for the Arduino Pro line, and Sparkfun's the closest I've found... \$\endgroup\$ – Crossfit_and_Beer Feb 5 '18 at 2:18

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