The 3D Printed Test Fixtures I Use For My Products

[@osgeld]

I design test fixtures for industrial scale production in automotive electronics, talking thousands of panels an hour, tens of thousands of units. our test kiosks can get over 100K in price stuffed with all sorts of gear from keysight, NI and etc. Our fixtures can range from 10-17K and carry dozens of amps, network communication(s) , fiber optics, camera systems and hundred's of pogo-pins. In a nutshell its exactly the same concept that you presented, just copy pasted a bunch of times lol. you pretty much nailed it

[@harrysvensson2610]

Are there any robotic arms with camera vision that automate any of it?
I'm just curious.

[@osgeld]

@@harrysvensson2610 I have one machine that inspects an odd shaped assembly, it has a universal robots "cobot". on its head are 2 camera's and a barcode scanner, one is doing machine vision to inspect wire routing and to inspect the headers are fully plugged in, the other is a laser scanner to measure the distance of features from reference points on the plastic base, that makes sure the boards are fully seated and the screws are bottomed out

[@osgeld]

@@harrysvensson2610 also if you were asking about at the panel / pogo pin level, management has been tossing around the idea for years so as a comprimise the fixtures have to be manually closed by something, then at completion they unlock and auto open by simple gas springs. They love the idea but with the cost and complexity vs having a operator doing multiple tasks its never happened where I work, once you have some automated system closing pinch points and apply pressure to things where a person is involved you get into some deep and heavy safety concerns.

[@osgeld]

if anyone is still reading, I just received an ICT test fixture that clocked in 1,823 pogo pins and it worked out of the box, minus the stupid ass barcode scanner that still refuses to play ball (no no no lets have the simplest thing connected to a freaking RS232 port be the hold up... typical)

[@nodriveknowitall702]

​@@osgeldsomeone is still reading. I've nothing of interest for a response. Your job sounds more interesting than any job one could land at my current place of employment. I've envied the engineers where I work, for their freedom in testing new ideas. I've loathed them when I've had to make their half-baked ideas work on a Saturday afternoon, after hearing that they left at 3 pm on Friday and instructed the operator (who is furious at this point) not to adjust anything. It's sometimes intriguing to imagine the chance circumstances that allow for such incongruities in merit and job placement. It's also interesting how often management overlooks the psychological aspects that affect production.

[@ferrumignis]

Nice job, with one tiny criticism; having a static display on the 7 segment displays means you could miss a non-operational segment, and maybe even two segments shorted if they are both expected to be lit. A test that cycled through each segment in each digit would allow you to see issues like this.

[@user-fy2tm2jg6c]

I was going to make the same comment. In my applications, I turn on each segment independently, then all on, then all off.

[@brickerhaus]

I have designed a few test fixtures in the past. I love that you show this and love your style.

[@chucksmalfus9623]

James, I’ve been running your ELS on my Atlas 10” lathe with a clear path servo since you first designed it, the system has been flawless from the get go. Thank you for your skills and attention to detail on everything you do.
Chuck

[@RNMSC]

As a Ham, I agree that the foot switch for powering up the rig for the boost board is a workable solution. Another that comes to mind is to find a space on the setup to mount a momentary switch so that when the board under test is seated in the test rig, it closes that contact, that works with the controller to activate a 1 second delay and then trip a relay that gives the board under test it's 5 volts, and the test begins. Optionally have a pass/fail indicator controlled by the main board, and after 3 or 5 seconds of test shows the results (less time if you need less time,) and power down the 5 volts so that you can then remove the board under test. That opens the momentary switch which clears the pass/fail indicator and you're ready to test he next board. (No need to remember to release the foot switch, or if you ever get to the point where you hand off that testing to someone else, train them in switching the power on/off with the footswitch.)
Having seen far too many 7-segment LED's with a single segment not working, would suggest adding code to turn on all segments in the display under the LED that shows which button is being pressed, and powering down the rest of the display so that you can verify that each digit in the display is good. I'm aware that since the display does read Clough42, each driver line is being triggered, so any failure in soldering the connections is already tested, but it's always good to go the extra 914.4 mm, right?

[@DavidLindes]

Or the extra 1609.344 meters. ;)
(Nice, I like it, just playing along. Also, 73's!)

[@StevenStyczinski-sy8cj]

Extended pogo pins for testing in linear or arrays normally have ground pins on both ends or all four corners so that ground is always the first to make contact. “Just thought I would mention it”. Or a zener diode on the 3.3 volt input test controller at higher than 3.3 volts but lower than the fry voltage might save the test controller from operator error or floor pedal problems.

[@abc-bm8pl]

Would dividing the output down so that even a 5v short is lower than the fry voltage work as a secondary backup to the multiple ground pins?

[@StevenStyczinski-sy8cj]

Dividing the voltage down in reference to what? Ground? That isn’t connected?
Your voltage potential will then be between whatever to were ever, points that may not be healthy to your electronics. So my answer is no.

[@abc-bm8pl]

@@StevenStyczinski-sy8cj between the receiving board's micro controller's input and it's ground reference. When there's no connection there will only be two resistors in line to ground. No problem. When the voltage input makes a connection before the ground, now there's a max of 5/whatever ratio to make it safe. Still no problem. Adjust the pass fail logic to suit the new voltage.
Thanks for the sass though....

[@Peter_S_]

Great job as always! The clothes-pin clamp is brilliant.
I have a lot of commercial production experience with pogo pins and I would highly recommend using the sleeves to hold the individual pin units. They do get flakey after a while and it's usually much easier to change a pin than a whole assembly. My jigs all use two layers of the same PCB with a little gap between them and the sleeves soldered into both PCBs.

[@johannglaser]

That was one of my concerns too. What kind of sleeves to you mean? Do you refer to the brass-like lower part, which James only soldered into a single PCB?
And 2nd question: How do you align the two PCBs?

[@RambozoClown]

Digispark. I love those little boards. Use them for all kinds of things.

[@krezac]

I think at the Kickstarter time they were called Stump. But I may be mixing it with another project.

[@MrVajutza]

I have a digispark running a fridge door alarm. It’s been running for over 4 years without any issues.

[@Segphalt]

​@@MrVajutza Digistump was the company, they produced the digispark, the digispark pro and the digiX

[@bradley3549]

I'm always impressed with the work you do. I'm over here just daunted by the thought of undertaking just one of your many projects and here you are not just doing a bunch of them - but also reproducing them in droves like some sort of electronics rabbit.

[@helixxharpell]

Nice video sir. Very informative. However, I'm more interested in 3d printing text fixtures. Could you do a short video on your approach to designing the fixtures? What materials you recommend? How you design them on the CAD? Thanks for all your effort! Great channel!

[@_soupnazi]

I recently came across some switch pogo pins that act like switches when engaged. My first thought was using them as a switch to signal when a board is clamped into the fixture. Might be useful in your situation as well.

[@jonnafry]

I find these videos great for seeing what's possible with resources available to everyday households - domestic industry - keep 'em coming.

[@ThatRobHuman]

Hunh! I've spent the last three days watching this whole series - I've been enraptured. How convenient a timing to be one episode away from the end... only to get rewarded with yet another episode! Brilliant!

[@Graham_Wideman]

Bot?

[@ThatRobHuman]

@@Graham_Wideman Nope. Actual real-life carbon-based soul-piloted meat suit.

[@brickerhaus]

I love your channel. I design circuit boards now but I worked in a Tool & Die shop for a decade of my life. I love your content. Subscribing Now.

[@jon_raymond]

Test fixture videos are the best videos! Thanks for sharing your knowledge and testing workflow.

[@telelaci2]

Wow, you do everything. Lathe, stepper motors and CNC machines, milling, turning, 3D printing, electronics. All at high level. May I ask what is your real profession. Do you heal human, can you cook? I'd like to see some good recipes.

[@marclevitt8191]

He is a software engineer. He has referred to himself as an autodidact.

[@shaocaholica]

He can sing too

[@Cybernetic_Systems]

Great video, I really enjoyed seeing your thought process manifested.
One idea that I’ve seen and used myself, is to incorporate a micro-switch into the PCB mount, so that when a board is fully seated, it’s depressed and then triggers a relay to turn on power and run the tests. It saves a lot of time vs a foot pedal IME.

[@romansholyak2332]

James , short comment regarding PCBA testing - try to not test them on any foam material, especially when you press buttons, you apply stress into PCBA , which can damage some components ( ceramics caps and glass diode's are most critical in this case ) . It can pass your test , but fail later on when this PCBA will be installed into lathe , where more vibration can finally damage components , which have cracks already.
Also you have V-cut on the panel - this can also add some failures , in case you test boards before separation as de-penalization is manual.
Maybe will be better to de-panelize them first and then test it on some printed fixture ( if you have material with resistance from 1 to 10 GOhm - it will be ideal for this from ESD point ). Anyway - it`s a great joy to see that someone test PCBA similar to production facilities !

[@newmonengineering]

Great designs. For the CF conductive issue, you could always just add a small piece of tape onto the end of the paperclip to insulate it. I use this trick sometimes when working with pcb. Excellent ideas and work. Keep it up.

[@robertsternlieb5532]

CrowdStrike might be looking for a testing manager 😂 Never will I ever do most of the things in your videos, but you do them so well and make the videos so interesting so I continue to come back for more. Very impressive.

[@medicallyunexplainedsymptoms]

For testing the 7-segment displays I always vary the pattern, such as alternating the on/off. That way you can spot any duff segments etc.

[@decee1157]

I love the concept of being able to make a simplified testjig. I have wanted to experiment with simplified jigs for awhile but never gotten a PCB that was simple enough but have enough challenging tests to do.
Some things that came to mind while watching the video. When making a PCB think about how you wanna test it and then put testpoints on the PCB because then you can automate the whole process and eliminate the worst thing which is human errors like looking at LEDS and such. I highly recommend having a relay to power on the device so you can systematically test the device when you are ready and not when the board gets plugged in.
When you then make your jig together with a DUT filled with testpoints, just make all testpoints available on the fixture, then you can always make a new bodge that connect the testpoint you didn't want to use initially.

[@karljay7473]

This is awesome.

[@briandodds]

How do you know all the segments in the displays are good it they are not all lit?

[@Chromevulcan]

Next to the incredible projects that you put out, these explanations are my favorite things about your channel.

[@billgilbride7972]

Micro computers are just too cool and you've capitalized on their capabilities, shared your knowledge about the project and how to put it all together. You definitely stand in front, on the side, underneath and yes behind. You definitely stand behind your product by not taking for granted third party involvement. Even good intentions need to be monitored. Heck you can be the one who got a bad batch of something or other. So thanks for checking them out and removing all doubt that delivered product has passed its QC Inspector #54 !!

[@IgnazKevenaar]

Love the red lens added in post. Works surprisingly well.

[@DemolitionManDemolishes]

Looking at your routing of 3v3 and 5v pins, are you working for Apple by any chance? Louis Rossmann would like to chat with you 😁

[@thoughtstream9591]

I think you could detect ground being connected there by eliminate the foot pedel operation. To do it you need a second pogo pin that hits the board under test's ground plane. Then put a very weak pullup on that pin and also connect it to one of theTI chip's input pins. It should be high until ground pin is connected well enough to pull it to ground. At that point the TI could turn on power to the board using a relay. Should get you a safe auto tester without the foot switch.

[@paulmace7910]

I know to the initiates to the sacred art of electronics this is pretty routine but to us mere mortals it is pure magic. It would be interesting to see the design process of how to use a simple microprocessor to do some simple task. I love electronics but have no idea how one goes about designing something at the breadboard level to do anything beyond switches and LED’s. I think some of your audience may be interested in how one goes about doing this amazing work.

[@TradeWorks_Construction]

You got better QC than most large scale production outfits that cost millions just to setup. I guess that’s the difference between large scale production and manageable batch production, at least for people or corporations that care about the quality they put their name on.
While I’m not one to bad mouth modern day QC in economical scaling while still enjoying the severely discounted price, I do hope that more companies can take a lesson from this kind of approach and offer a product that is slightly more expensive but demonstrates a level of reliability head and shoulders above its competitors such that most modern consumer would find it hard to justify saving a few dollars to buy its untested mass produced counterpart.
However for that to become viable a more robust system of product rating that users can trust would need to be implemented, it’s something that I’ve wanted to implement for a long time as our current model to easily blends issues with the manufacturer, seller and shipper together and assumes the same product produced today is identical to what it was 5 years ago.

[@VladekR]

Laziness is a motor of invention 👍👍👍👍👍👍

[@AlexMusayev]

Thank you for the video! Workflow automation is one of my favorite engineering areas because it can provide very apparent benefits, such as higher product reliability and time savings. An the important part is that it makes your work incredibly satisfying 🚀I know those are obvious facts, but anyway. Automation FTW!

[@BloodyMobile]

6:45 it's incredible how delicate and tiny those things are, that finger holding them looks like a beach ball in comparison to the size they /look/ like on video.

[@int2str]

Fantastic video, great info! I've been meaning to make some test jigs for my boards and really appreciate this run-down. Great eye on detail as always - well done!

[@jlamoree]

This is really valuable information. Thank you for sharing these techniques. I need to make a fixture to hold a board with a tiny Atmel chip for programming.

[@neosenshi]

I really like the little pcbs. We use 5 pin headers at work for programming. Something like that would have made programming fixtures easier to build. We ended up getting an ICT company to make some for us.

[@buildtestbuild]

Fantastic video! I appreciate you sharing these ideas, planning on making some test fixtures as well, so very timely.

[@minilathemayhem]

I'm not sure why I've never thought of using 3D printing for PCB testing jigs before. It's an obvious use for it, really. Also realized it would actually be really nice for making jigs to align PCBs with solder paste stencils.

[@MinnesotaHomesteading]

We use printed jigs for solder paste. Incredibly awesome for 2 sided boards.

[@Graham_Wideman]

@@MinnesotaHomesteading I assume you mean that your 3d printed jigs help align a conventional stainless steel solder paste stencil, right? Cuz I've tried 3D printing the stencil itself, and the result was not pretty!

[@MinnesotaHomesteading]

@@Graham_Wideman yes, correct

[@AJMansfield1]

9:30 For testing a full panel of ELS boards all at once: Have the tester come from the top rather than the bottom, and make it a hand-held item you plug down on to each board in sequence. (That would also let you test the LEDs automatically, with LDRs at the bottom of printed aperture tubes pointed at where each LED should be.)

[@plb53apr06]

A subject near and dear to my heart. Very good discourse on test fixtures.
The only thing I would like to have seen is how you extract the positions of the pogo pin holes from the original board and put them into the test fixture design so they align. Similarly for the 3D printed design for pogo alignment. I suppose it was just manually copying the x, y position and translating to a different origin but would love see some sort of automated extraction.

[@RNMSC]

All 3 boards are using standard 1/10" spaced connectors that he's using to set up the pogo pins with. Set up the array needed for the IDC/Dupont connector being interfaced with, then get the spacing from mounting holes or board edges being used for alignment, for where to place the array of pogo pins, (* Since he's designed them himself, he can extract that information off the files used to generate the Gerbel files for the people manufacturing the boards) and design your fixture around those constraints and proper holes for the pogo pins to fit through, as part of the 3d print for holding things together. This is also demonstrated with the second and third fixtures which connect to the testing setup with regular dupont connectors in a 3x4 and 3x5 array setup.
Note that not all boards on the market use 1/10 spacing for contacts. I have a couple of Wifi Connected USB switches that have their UART interface on 1.27 mm pads. (I'm not sure if that's spacing, or the size of the padd, 1.27 mm or 1/20 of an inch, a bit tight. The ESPHome page for the device notes that one of the devs simply used two standard dupont spacing boards, one on the front of the board, the other on the back, offset half the 1/10" (2.54 mm) spacing to connect the other set of pins. Be sure you have the mount set u right, eh? Otherwise you have ground and voltage on a gpio and data pin, which isn't likely to work out well.) Another simplu used needles pressed into dupont connectors, and may also have pinned the board from both sides, but could have 3d printed a fixture to hold the needles so that they plugged in correctly, with handy reminders of which end was ground.

[@Graham_Wideman]

ECAD software like Kicad outputs a list of hole positions in the drill file for the PCB manufacturer. So you can take the PCB file of the original board (the board to be tested), delete all the components and vias you don't want to test, leaving just the ones you want to test. Then output the list of hole positions. But that seems way more work than necessary. Instead, you can just use some variation of copying the board-to-be-tested (or an image thereof) and use it directly in the PCB design of the test fixture. No numbers needed. Once you complete the PCB of the test fixture, you can export it as a STEP file into the MCAD package and design the mechanical fixture around it.

[@usualneko8894]

Hi James! I seen that you use reinforcement filaments a lot. You mentioned in this video that CF-filament may cause issues with connections, so you want to try glass fiber filled filaments in next time. But, is that extra rigidity is needed in many case? I mean, i use "basic" materials like PLA\PETG all the way and basicaly no have issue at all. You use this materials in sort of enclosures, so and i. Yes, some time i need some tweaks like adding some additition layers, or make through holes (for extra internal "outer" layers), maybe some ribbs, but thats all. But this "filled" stuff have thtoughout entire volume, including outside layer, a small chunks of carbon fibers or glass, thats can easyly stuck in skin and clothing. What happend (and can it) when this particles will end up in body, eyes, lungs? You drop wery good video about electrical condactivity of reinforced matterials, may be you did some researches about interraction this particles with body? Because publicatons that i found does not inspire to use material like this in every day without strongest reasons. Thanks a lot!

[@colinrhodes643]

Wow! This is next level. Great work James.

[@andyd777]

Awesome video. Look forward to commencing an ELS project with your products and videos

[@jimruddy6083]

Wow! An incredible amount of design and redesign work wen into these test fixtures. I wonder if current EE curriculums cover this? I know they didn't back in the dark ages when microprocessors were just beginning.

[@DustanWebb]

A DIGISPARK! I have some of them too!

[@jeanbarbier9448]

Hello James,
As a side note I went back to the ELS project to see what EEPROM was planned (and can still be enabled in the firmware it seems).
It was an AT25080B like, an SPI model which is far less common than I2C ones.
It seems however to be again fairly inexpensive, less than 0,50€ (VAT included) by Mouser in France...
That said, a very interesting set of test jigs (I did industrial testing in a far past)...
Cheers

[@bradgeary3467]

cant wait for second axis! My unit, thanks to your hard work and QC has run ABSOLUTELY flawlessly in my Ebox. had placed an order for ELS4 pro but there was issue with billing address and in that time I decided to run your system with fingers crossed you (or someone) make available a second axis ability. no idea if most the hardware would even support 2axis but one can hope and dream :)-

[@simple_fred]

Did anybody suggest gating the test initialization on logic low on an alternative ground pin with a 10ms to arc pair. In short, use a ground on the logic bus as an input with a weak pull-up resistor on an input. After you debounce the input with a delay, you can trigger the power circuit using an enable pin.

[@Graham_Wideman]

"with a 10ms to arc pair." What does that phrase mean?

[@simple_fred]

@@Graham_Wideman that is an example of auto-incorrect. In my past at a semi fab, we paired “ground” inputs, but where one of them was an input. Either applying a negative voltage or pulsing a voltage, triggered a diagnostic procedure. My suggestion was to run a small current through the pcb with a small delay before executing your test program. Let’s say you have power ground and digital ground, but digital ground is also an lnput. Positive power is withheld until the active low circuit to digital ground is maintained beyond the time threshold relative to power ground.

[@Graham_Wideman]

@@simple_fred " we paired “ground” inputs, but where one of them was an input. " ???

[@simple_fred]

Oh poop I am worried that I am still being unclear. You can use a ground circuit as an input to detect the presence of a DUT (device under test)…

[@simple_fred]

@@Graham_Wideman it’s been a decade or so since I moved on from that fab in Sunnyvale, but the trick was to offset one ground plane from other to signal to the die that it was in a bootstrap mode and than the prom functions were engaged to hone the internal variables. The key is that the tester would monitor the current between the ground planes before triggering the programming.

[@pecilijevelicanstveni4973]

Every video reminds me why you are my absolute favorite! Extraordinary!

[@mikemike7001]

The little microcontroller board is a Digispark, with an ATtiny85 and a 78M05 regulator. Digistump, the original manufacturer, is no longer in business, but Digispark clones are readily available.

[@envisionelectronics]

The tester stops due to ESD. Add TVS diodes to the open ports.

[@kl1nk0r]

Your microcontroller probably crashes due to the inrush current when connecting the connector to the LED/Button board. Some current limiting circuit (or IC) in between will probably enough.

[@beachboardfan9544]

Would you go through your design process or share some of the sources you've used to learn about IC design?

[@kurtbilinski1723]

I'm hesitant to mention it - because I'm not sure what I'd do myself - but the static display board test misses doesn't test many of the segments. Maybe have one segment "run around" each digit?

[@jordanporter2308]

I’ve watched for a while now like 18 months or so
And I just came home from a night out and thought hmm it would be nice to wind down with a video
And I found myself humming to the entry jingle 👍

[@Graham_Wideman]

OK fellow Clough fans. Reading this comment -- Bot or Not?

[@jordanporter2308]

Not
Thanks for inquiring tho

[@ThatRobHuman]

@@Graham_Wideman why are you in everyone's comments asking if they are a bot... and getting it wrong more often than not?

[@marclevitt8191]

⁠@@ThatRobHumanI like the rhyme. 😊

[@Graham_Wideman]

@@ThatRobHuman Not _everyone's_ comments. Just a select few that don't make any direct reference to the video. Why? Because as we interact with the comments, we're also under some pressure to refine our ability to detect which comments are from bots, in the face of AI becoming more prevalent and seemingly capable of generating plausibly-human comments. So I make some guesses and poke for some feedback. (I see you agreed with me on another one, which looks to have been deleted now.)

[@jstro-hobbytech]

I don't always agree with you, James. But damn if I don't love how you operate and lament the lack of like-minded people. Respect and thanks for the great content.
I etch my own custom boards from time to time. What's the best way (in your experience) to diy plated through holes? Only if you've done it yourself before. I'm not a fan of contributing to the gdp of China so I avoid their board houses as much as I can. I bought a bottle of mg chemicals liquid tin at a great price once and waste not want not right. Haha. I do consulting for a local repair guy for psu repair as a hobby and I'd love to add plated through holes to add extra mechanical strength for edge cases.
The led and key boards are shit. I donated a bunch to a local non-profit for a course they put on and they were mostly shit. I grew up extremely poor and waste kills me. Most pads on blank prototyping pcbs from china fall off if you look at them the wrong way. I use vector brand veroboard for prototyping from digikey. Busboard systems isn't bad either if amazon has it on sale.
Take care brother and continued success.

[@Graham_Wideman]

"best way (in your experience) to diy plated through holes?" The best way is to just order PCBs online. Then you can have solder mask and silkscreen and a result that's respectable enough to show off. Making your double-sided PCBs gives a poor result and is pretty much pointless in this day and age. Unless your hobby interest and enjoyment is in the actual making of PCBs with no regret about the time spent and primitive results, and you're not so interested in the electronics.
"Most pads on blank prototyping pcbs from china fall off if you look at them the wrong way." Really? I must have used hundreds, from different generic brands, and have never had pads "fall off". I can't deny that you may have encountered some, but usually, pads detaching is usually a sign of overheating the pads and abuse during desoldering.

[@Clough42]

Thanks for your comment. I have etched a few PCBs in my day using presensitized boards, spray photo resist, and even toner transfer. The results were always mediocre at best. I was thinking about getting geared up to give it another go about ten years ago, but by that time, OSH Park was up and running and the quality of the boards you can get and the pricing make home etching impractical, unless you have a simple project and need it today.
I haven't had any issues with lifted pads unless they're mechanically stressed or overheated. I run 100% lead free solder and use a temperature controlled iron and I can't remember the last time I had that happen.
I respect your desire to avoid going to China for PCBs. I think OSH Park is still manufacturing in the US, and there may be others.

[@jstro-hobbytech]

@Graham_Wideman the shipping time isn't worth it and I'm 40 and retired and have all the time in the world. You do you brother. I actually have a pcb order for something different right now but keep your opinion to yourself man if you're gonna be snide.

[@jstro-hobbytech]

@Graham_Wideman and I was talking about cheap perfboard ya dummy. I've been soldering for like 30 years, I'm not an idiot. Somethings just arrived not worth the effort or shipping when I have all the chemicals here. It's not a matter of money. Ask your mother.

[@jstro-hobbytech]

@Clough42 I always forget about osh. I paint fr4 and etch thr paint off with my laser if I'm in a hurry. I was talking about Chinesium perfboard and soldering kits when speaking of lifting pads. I should've specified as it activated part of the peanut gallery. Thanks man.

[@holgerlauer]

Thanks a lot for sharing all these information.
Alsolutely PRO 👍 as usual

[@chrisj4570g]

There’s a less than zero percent chance I’d ever need this info.
But if I did, I have this info. Which is good.

[@anniebooo]

Thank you!

[@ChatNoirLe]

Ah, itsy bitsy power boards, you've reminded me I never tested the quiescent on a couple of mine, even though that was a spec I wanted...
Are the boards cleaned, residue can add a bit of parasitic?

[@madguernseyboy]

Do you sell the display boards without the other ELS parts (red screen 3d printed parts etc) I am very interested in getting a few!

[@Tome4kkkk]

Wow, I mainly know you from machining videos :) What kind of workshop-oriented electronics do you sell the most? OT: Any recommendation for an open-source oscilloscope project that is actually useful? I assume there will be no analog ones...

[@GeorgeGraves]

$30 eprom? What ya takin' 'bout Willis? Are you using eproms made of unobatinium? That's a jellybean part.

[@mfx1]

Why not use a simple/cheap 5v tolerant micro to run the tests, there's no real reason the boards have to be tested using the target platform.

[@Graham_Wideman]

James is in a rather testy mood today.

[@marclevitt8191]

Don’t test him. He can get testy. “ Testes, teases , one, two,….. three?” Beavis and Butt-head

[@MinnesotaHomesteading]

I would remove (or black out) the eeprom led. It is easier than you think for the brain to get used to ignoring the red indicator, then it misses genuine failures.
Also, in a revision, consider separating the revolving LEDs further apart. Again, the mind gets lazy.

[@Kmnri]

Impressive ideas, may borrow some of them fo myself :D

[@ingmarm8858]

Very nice!

[@muzzdeni28]

Just in time for my lunchtime viewing.

[@boldford]

Although not a great saving I'm surprised you retained all eight press buttons on your spin of the Key & LED boards.

[@Speedgaming802]

cool!!!

[@opieshomeshop]

*_I just realized that your entire existence is way over my head._* 🤣👣👣👣👣👣👣👣👣👣👣👣👣👣👣👣👣👣

[@joell439]

👍😎👍

[@jamesdstallard8743]

Can I buy them in the UK yet? 🥲