How To Create a Test For Your Boards - Everything essential you need to know (with Sean Hadley)

[@NickAlexeev]

I like how Robert was keeping Sean honest during this interview.

[@amrahmedabbas]

Thanks Robert for this video I'm working with my team in test jigs development for about 4 years. We have many vergions based on the tested board. We can now test up to 14 analog signals, 20 digital signal, UART communications and the visual test of leds, switchs and lcds Thanks for spreading knowledge

[@kossieseii85]

Test Jigs Development: I didn’t know that was a thing. Thank you for this comment 🤩

[@OnlineQuranAccademy573]

السلام علیکم احمد عباس بھائی میں اسے اردو زبان میں کیسے یہ ویڈیو ڈاؤن لوڈ کر سکتا ہوں… کیا آپ میری رہنمائی کریں گے ؟؟؟؟

[@РоманВесельский-ж8о]

One of our manufacturer tells that test points should be not less then 1.5mm and they don't allow to use vias as a test point. They explained, that during test, force from the pogopin may damage cooper and influance on connection.

[@jlysiak]

Incredible content, as always! ;) Keep going 👍

[@RobertFeranec]

Thank you very much Jacek

[@chromatec-video]

This "Dude" Sean is pretty cool - but a DAQ solution is fairly limited. A good follow-up video would be modelling the 3D jig and software required to organise a 3D printed or CNC machined jig. UK sounds a strange source for pogo pin manufacture - could Sean please reveal his contact there?

[@DehimVerveen]

I was wondering if/how it's possible to perform panellized testing prior to routing/v-grooving the panel. I have an idea for a board that would use finger connectors and I thought it would be cool if I could test a panel at a time. I think it should be possible to extend the finger connectors and use those lines directly to perform tests. Then when testing is done, the panel can be routed. I don't know of a PCB manufacturer that would offer such a service. I could just design a test board that would accept my board and do testing that way. This will probably be the initial direction I will take, but I think the idea I describe above would be a lot faster at higher volumes. I also don't want to go the direction of routing traces across v-grooves or mouse bites.

[@theondono]

Unless your panel has all the boards on one side (Nx1 or 1xN arrangements), I don’t see how to make that work. I don’t like routing tracks through mousebites, but I have to admit that when done properly it is a very reliable and nice way to do some stuff like JTAG programming.

[@krzysztofkwiecinski148]

Most of assembly houses would do QA on assembled panels (AOI, ICT, etc) acoording to their toolinig, there are Flying Probe machines able to perform ICT small batches of boards, if You want anything extra You have to provide tooling. If You want to prepare test for panel you can have two main approaches - create tester able to test all boards fully parallel, or you could have tester for single board and then use multiplexers to test one board at the time, or you could do some magic with software to split tests to couple jigs able to perform one simple test at a time, and then schedule execution in such manner that diffrent test can execute on every board in the panel in one moment, but ultimatly every test wolud be executed on each board in shorter time than executing it sequentially.

[@supernumex]

eevblog has a video on exactly this topic. testing in panellized form before routing.

[@DehimVerveen]

@@supernumex Do you have a link to this video?

[@supernumex]

@@DehimVerveen kzbin.info/www/bejne/i3a2lGqjqJmYnNE or search. eevblog #588

[@rjordans]

For getting the digital protocol interfacing running we've been using plain old FTDI MPSSE breakout cables with the pyftdi library. Fixturing itself is done using a custom pcb with sensors (actually an extended version of our development fixture) set in one of these Ingun boxes. A bit of self-test in firmware but most of this using the fixturing pcb and python code. Also, if you get things like a larger FPGA on your board these often have their own power supply monitoring that you can use for testing/monitoring.

[@RobertFeranec]

Thank you very much Roel for sharing this.

[@rjordans]

Maybe one thing to add here, having a test fixture early on in the development process makes life so much easier when debugging boards. Especially when you want to compare different boards or revisions. Just the repeatability of connecting all test points makes this a time saver for our more complex designs.

[@iliaslolis1769]

How do you wire the pogo pins? Do you solder them on the custom pcb or wire them to it?

[@rjordans]

@@iliaslolis1769 we soldered them directly into the pcb. I haven't had problems with the heat of soldering affecting the spring but that may be something to think about. If you want to have an easier job replacing them when they get bent, or avoid possible overheating, you can also get sockets for them that you can solder into the pcb. Usually these sockets are not designed for pcb use but more aimed at wire wrapping the connections by they work fine when you have figured out the right hole size in the pcb.

[@instrukcion14]

my experience is that there are a couple of products that can do self-tests. The main chip turns to the unit that Sean designed. Unfortunately, you have to count on the testing procedure in advance and be aware that all features related to IC cannot be tested. Personally, I do not like placing sense resistors on target boards because it is just another component that can blow up. Still, there must be a compromise.

[@vejymonsta3006]

LabView is actually incredibly easy to learn. The issue with NI is that you get stuck in the ecosystem easily, and it's very expensive.

[@RobertFeranec]

Interesting. Thank you. VejyMonsta

[@NickAlexeev]

I'm happy to hear that Python is displacing LabView in new test setups. There's recurring theme at companies who made a mistake of going with LabView. "We had a guy [an employee or a contractor] who programmed LabView for us. He left the company and moved out of state. Now we can't find anyone to maintain our LabView programs." I've heard this sort of story at least three times at small- or mid-size companies. LabView makes simple things easier to learn, but LabView makes more complicated things harder to implement.

[@kossieseii85]

@@NickAlexeev good to know. Thank you for sharing your views on this topic. I’m really enjoying this channel

[@ds-dronebike]

Thanks for this video.

[@parkuorman]

Thanks for great video again Robert. Some additional comments from former test developer. With commercial test fixtures you fairly may go to 0.8-1.0mm in diameter of test pads. There are suppliers who are focusing to even smaller test points diameter as 0.4mm, just those are crazy expensive and very fragile. Hitting directly to through hole connector leads it is not recommended as these may have flux residue left after hand or automated soldering. This may cause probes to be dirty and cause bad contact. JTAG Boundary Scan is really nice tool, just with limitation to cover full board functionality as it can check inly digital part or interconnects, analog part and voltages are still limiting factor here, so you may need still voltage, current, resistance measures. Especially if you have some kind of more complicated circuitry on board. Would it be possible to include additional videos of schematic or software tips&tricks for reliability, redundant design for life critical design? Or radiation (satellites using COTS components) tolerant design concepts, architectures or low level schematics tricks?

[@theondono]

I’ve been in the same situation a lot of times, I’m now planning to check Blue Clover Devices PCT for some boards I’m making

[@theondono]

Also Robert, a fast way to check if LabView is for you is to check videos of people programming Lego Mindstorms, their system was based on LabView and there’s a lot of teaching materials for kids. It’s not the same, but is a quick way to get an idea. I’d rather use some scripting language though.

[@RobertFeranec]

@@theondono Thank you

[@krzysztofkwiecinski148]

High density boards often use JTAG for testing, it's very versatile tool in test engineer toolbox (allowing testing and firmware upload) ;) but software can be costly :/

[@vejymonsta3006]

You're almost always better off with a standard off the shelf connector for testing.

[@krzysztofkwiecinski148]

@@vejymonsta3006 And using JTAG helps to achieve this goal.

[@RobertFeranec]

Thank you Krzysztof. PS: I remember, once we wanted to test one of our x86 boards through JTAG ... the price for that was astronomical. We have never used it since.

[@parkuorman]

uploading firmware into the board using JTAG may be not so good idea timewise especially if there is big JTAG chain and file to upload is big. It is directly caused by JTAG principle which is just long shift register, so if big chain, then really long time to upload. But hey for some of us length of programming is not an issue, it may be an issue if you have bigger volume of production

[@bobby9568]

Was waiting for this one!

[@RobertFeranec]

Me too. PS: I would like to make more videos about testing, let's see if I find more people to talk about this topic - especially testing boards manufactured in huge quantities.

[@bobby9568]

@@RobertFeranec I am looking forward to it and I hope you can find more people to talk about this very interesting topic. As always thank you Robert for providing high quality content!

[@surendramaharjan3129]

Sir, could you please teach us how to get pcb negative print on glossy paper for hand made pcb in altium designer?

[@siddharthmali5841]

Excellent. 🙃

[@RobertFeranec]

Thank you Siddharth

[@artstaliarou9968]

Nice video. Binho can be replaced with usb2io device (usb2io.com)

[@OnlineQuranAccademy573]

Hi My Respectible Teacher One Question For You how can watch this vedio in my language.??? my language is urdu.!!!

[@kirans862]

Nice Content :) For dense PCB's designers use an additional hardware like BST circuits specifically for testing of the boards. For current measurements i feel placing sense resistors in the pcb and measuring the voltages from the nails through DAC is better.

[@RobertFeranec]

Thank you Kiran

[@rockndancenroll]

COuld we know from which place in the UK he buys the probes please?

[@Graham_Wideman]

He's showing links at Adafruit. Here's their products listing for pogo pins: www.adafruit.com/category/458

[@Graham_Wideman]

Ah, I see what you're referring to, at 58:54, perhaps it's these guys: www.peaktest.co.uk/

[@OnlineQuranAccademy573]

kindly guide me i want to see this video in urdu language pleas🙏🏻🙏🏻

[@rockndancenroll]

Also, I'd like to know what his feelings were after the news about the Christchurch shooting (offtopic). I'd be very mad and sad.

[@NeilStansbury]

OMG! So I'm a software engineer not an EE, and I (rightly) get lectured by EE's about my schematics and layout and decoupling caps etc etc, so now it's my turn. If you write software tests that look like that, you should be lined up against a wall and slapped with a wet fish. Seriously, a bunch of "if-else" statements to a stdout *is NOT* a test harness. I am genuinely mildly horrified by this video. EE's need to spend less time worrying about a diff-pair impedance and more time mastering writing decent software. This is about as far from "best practice" as you can get.

[@KevinRegan875]

How should it be done in this situation?

[@phenyl22]

Do you happen to have a link to some example of a better implementation?

[@danielvilasperulan8158]

For example using “unit testing” kits

[@xzoli79]

Getting your differential pair impedance may be crucial to get your product right and that's what you get paid for at the end of the day. Having designed a few (basic) test jigs myself, their development always tend to fit in at the very end of the project, when the production is already in place and you need to deliver fast. Usually there's no time for pretty coding, especially when all the software engineers are involved in something more important and you have to do it yourself. I am more concerned about the lack of freewheeling diodes on the relays - if this is the final version of the schematics - see 22:02 . It's a pity to spend a few hundred dollars on a product just to end up with a broken board after a few cycles of a relay. Tip: don't place your test points close to through hole solder points, they might end up with solder or flux on them. Robert, love the video, keep up the good work!!!