The Magic of Pogo Pins: Building a Custom Programming Fixture!

[@Peter_S_]

I've built many fixtures and used them in mass production of commercial products. I always used Harwin pins and they worked great, but they do get slightly flakey after several thousand cycles. I only use pins with sleeves which allow you to replace the actual pogo part. I made PCBs to hold the sleeves and used a pair of boards stacked with a 1/4" standoff in between.

[@AllTradesZach]

Good info, I also believe their 10,000 cycle rating is a little optimistic. They have a tendency to stick if they're dirty or abused. But that's still more cycles than pretty much any other connector.

[@gesoocreesto6374]

may I ask, what kind of product did you put these on?

[@Peter_S_]

@@gesoocreesto6374 I only put programming pads on the bottom of the PCBs for use in manufacture and the programming/test jigs contain the pogo pins. I've never used pins in a product design. In production, the jigs with pogos (made from laser cut acrylic and PCBs) were used for providing power, testing analog values, testing digital values, and programming microcontrollers which were stuffed as blank parts to avoid Digikey's $0.25 per chip programming fee and first article delays.

[@bigjd2k]

Coda pins, last forever… and are socketed when they finally go!

[@dumle29]

@@AllTradesZach We mainly use POGO-25 from everett charles for our stuff. sleved as @peter_S_ mentioned. They're rated for 1 million mechanical cycles.

[@jercos]

A fascinating historical example was the board stacks used in Cray supercomputers... each PCB was loaded with chips and pogo pins, and dozens of boards were stacked with spacers, interconnecting them all in 3D.

[@BLOCKsignallingUK]

If you make the contact points on your test pcb to be holes the size of the pogo pins, then use pogo pins with heads larger than the hole they fit in, then you automatically have pogo pin jig with the pins in exactly the right place to line up. If you use two unpopulated boards to accept your pogo pins you can have a very heavy duty connector. I have some where when thay are applied to the board a ground is detected on one pin and this automartically triggers the programmer.

[@cesarqueti]

I think this is the first video I've watched of your channel. I didn't know what to expect... I thought you would talk about pins and pogo pins, but man I'm stunned with the overall process to make an automated testing and programming jig. The modularity of the assembly for further grow is great.

[@cburgess5294]

As someone with a small Electronics business, I use pogo pins to build test jigs regularly and even use them in some of the products I sell. You can get them with 1.2mm conical tips that mate with the standard .9mm through-holes. No need for exposing test points.

[@TheWufgeng]

I work as a test engineer for series production testing. Mainly for functional testing, but we othen use test needles for connecting to test points on the PCB. These needles a commonly used in the business for electrical testing like ICT. Those needles come in many different shapes and can be a bit pricey. They are maDe to Be easely replaceable without soldering as these can wear out when talking about mass production. The hardest here actually is making the fixtures that must be made in precision to reliable connect to each test point. There can be up to hundrets of spring loaded needles on one fixture. It is basically its own engineering field.

[@jeremiahrex]

Looks really good! Some thoughts I had while watching. If you export a STEP file of your product PCB, you can import it into the Kicad project of your tester PCB to verify correct positioning. The datasheet for the pins will also call out how far the pins need to be depressed to function correctly. Too little and you don't get enough pressure from the internal spring, too much and they'll push through plating on the contact pads. I work with a company to design the mechanical fixtures and they regularly hit the 10k cycle rating. For fixtures that will see more than 10k devices total we usually use simple standoffs to set the distance. For medium to high volume products there is a special carrier plate made of Delrin that holds the pin bodies because it's easier to service. Not necessary for single digit thousands.

[@makerspace533]

They have been around for a very long time. Fifty years ago (hard to believe it's been that long) I was designing and building production test gear for calculator production. Some of the board testers would run 25,000 cycles per day. Pogo pins can be used in a special socket that makes swapping out the pin very quick and easy.

[@user-xb5zu6zu7j]

As always, excellent video, inspires me to try it!

[@md.mostafakhan4529]

Back in the golden era of Nokia, many phones had to be flashed using cables/connectors that used pogo pins for connections.

[@savagesarethebest7251]

I was really fascinated by this as a kid, I even found "DOS" ported to some model of Nokia and you had to type "CALL 0..9" 🤣 I am unsure if it just was a joke or not.

[@kayakMike1000]

I recall this.

[@PatrickHoodDaniel]

Great video!! I've been wanting to use pogo pins for testing circuits for a while now. Programming the microcontroller is a very good use for pogo pins.

[@AlexanderBurgers]

Another alternative solution for the low end, there's the pogo pin 'clothes pin' clamp. It connects pogo pins to what would be the footprint for a programming header, but without having to solder the header to the board. Not quite as compact as only pads, or as comprehensive as the full pogopin jig, but if the product already had the header footprint anyway to connect JTAG/SWD/ISP/etc.. it's a good solution. Similar to TagConnect (just cheaper).

[@MatthewWilson-n6r]

Tag-Connect is another great option that is free on the PCB side

[@AllTradesZach]

Looks like it requires a little larger footprint, but that's a good suggestion for an off the shelf solution.

[@AuthGate]

...and horrendously expensive on the connector side. :-(

[@pe5erbarnes]

Wurth sell something equivalent, but with much cheaper connectors

[@AuthGate]

@@pe5erbarnes You are right. I use their 6 pin 490107670612 connector on most of my boards. It does require a little more PCB space than the Tag-Connect system, but is significantly cheaper. Just note that need to use slightly larger PCB holes for temporary connections. The documentation sheet provides the information.

[@satibel]

Well, it's basically just pogo pins with extra steps

[@zyeborm]

robert fenerac(sp?) just had a video on this exact topic including a range of test suites and things. Worth a watch

[@pRoFlT]

pogo pins are great. I've built sooo many fixtures with pogo pins for manufacturing. Getting engineering to ad test points is such a pain though. I've used phenolic board and Delrin to hold them for small fixtures. Even did 3d SLA fixture for temp fixtures. i like crowns the best. balls i've never used. much easy with spike crown or bowl for large through hole pin connections. solder process sometimes leave a little residue on boards. so spike or crowns can most of the time push through that layer and make a better connection.

[@theSquashSH]

Looks awesome, would be sweet to use this connector style for charging some little LED projects I have.

[@pjforde1978]

This is actually... really great, Zach! You've inspired me. I do my programming via USB but it is tedious for all of the reasons that you specified. I've been intimidated to commit to designing a more integrated testing rig as well, but it's easy to perceive things through the lens of doing everything by hand when you're working with samples vs production. I'm also actively trying to level up my Fusion skills, and one of the hardest things is to find intermediate projects that aren't superficial tutorials. Any chance you'd consider sharing your .f3d?

[@AllTradesZach]

I could be convinced... I will say though, I've used pretty much every CAD software out there and Fusion is my least favorite. I'm just sticking with it at this point because it is free for hobbyists (although they've steadily taken away features) and I have a lot of models in it. I could rant about what I hate about Fusion (the mating of parts in assemblies, the convoluted feature tracking system that seems to randomly shut off requiring me to remodel parts, etc.) but I'll save you the time. I think trying out FreeCad is in my near future.

[@pjforde1978]

@@AllTradesZach I started with SolidWorks but decided that navigating a Kafka-esque multi-variate licensing hell including forced interactions with literal zero value add resellers was not how I wanted to spend my life. Whereas FreeCAD is worth what you pay for it. Fusion is not without issues, but I kind of love the workflow. FreeCAD's UI/UX feels like it was created in a university lab by people who hate users having good experiences. One thing I find genuinely strange is people hating sophisticated software tools because they aren't free. I work on OSS tools myself, but when it comes to a professional tool, I kind of want people who are paid to focus on it to be steering the ship. I'm trying to imagine any other sphere of life where you would demand that your electrician wire your house for free. You wouldn't want that person near your mains box, so why would you want to design a spaceship in something people only did as a hobby?

[@ncx94]

Very nice project! Funny, I'm also working on a custom "universal" test/programming board at the moment! Maybe something we could bring together?

[@fgregerfeaxcwfeffece]

Most common types of plastic only start to get really soft around 300C. So there is a decent chance your solder temperature is a good bit lower. Still for fume reasons I would not put a lot of them in the oven depending on the ventilation in your space. I checked reflow oven temps 220-250C for 120-240 seconds Okay, that's probably fine if you don't intensely sniff it the entire time.

[@osmanpasha_diy]

There are also much longer pins P100, P75, P50 which can be soldered through-hole and are much, much cheaper (couple bucks per hundred).

[@malachilandis9542]

So cool to see a video about something I used to do at work. The company I was with would do lots of automotive parts, things like the boards in the dashboard display. I was mainly on the mechanical side of things. We had a standard test fixture design which we would make G10 inserts for rather than PCBs, so we would use the pogo pins from QA and wire them all to a connector at the back of the fixture. Is this something you do a lot at work or something you've figured out yourself? I am new to your channel. One other interesting thing from production electronics is wave solder pallets, though that is probably outside of the realm of hobbyist electronics.

[@kurtandlazanneilander724]

Is that a homemade reflow oven I caught a glimpse of? Do you have any info you could give on how you made it?

[@cdyoutoob]

Looks like Controleo3 from Whizoo.

[@AllTradesZach]

It is indeed a Controleo3. Not the cheapest thing in the world, the kit is ~$300, but it works fairly well. Pretty accurate on the heating, could probably get it better with some PID tuning. My biggest complaint is that the cool down isn't well controlled, I wish there was some active cooling.

[@kurtandlazanneilander724]

@@AllTradesZach @cdyoutoob thanks for the info! I'll look into that.

[@pjforde1978]

@@AllTradesZach interesting! any hot takes on Controleo3 vs ReflowMaster?

[@AllTradesZach]

Hmm, first I've heard of the ReflowMaster. Looking into it, it looks like the ReflowMaster is basically just the controller, perhaps with thermocouples. The Controleo3 is a full kit - insulation, SSRs, tape, silicone, an aluminum tray, and extra heating element, wire - even a band-aid (which I did end up using). The insulation and whatnot could really add up if purchased separately as well as the time to track down all the parts. Plus the instructions are reasonably thorough. Ultimately, I wanted a reflow oven that worked, not another project, and the Controleo3 seems to fit that (after 4 hours of assembly). I might be doing the ReflowMaster an injustice though, as I've said, I haven't extensively researched it.

[@sNEAKYnIGHTmUPPET]

why do I get the feeling that there is a video missing before this one? That is a whole new PCB Zach! C'mon, you're developing without us? I thought we all had something good going on here; Teamwork

[@AllTradesZach]

I know, I know, I'm sorry... In my defense I'm rolling through revisions faster than I though possible. What do you do after 'Z' for rev letters?

[@michaelcummings7246]

​@@AllTradesZachI use semantic versioning on my hardware just like I do for software it's just easier. 0.0.1 - 0.0.42 ... for the win in most of my projects😉😂

[@ComplicatedStuff]

Put the pads on a 2.54mm grid, so you can make the fixture pcb with the pins on an experimental board.

[@taisenification]

Where do you buy your pogo pins and can you find them for a reasonable price?

[@v1ncen715]

I recently bought a product that unfortunately came with a charger that has pogo pins with magnet. I need to replace this with a fixed connection.What 's the best way to fix it with attaching cable instead? Can I solder wires directly to the flat contactors that are supposed to have the pogo pins pressed against?

[@ShopperPlug]

8:38 - how did you make that oven?

[@AllTradesZach]

It is a Controleo 3 kit. Scroll through the comments, I talked about it in more detail in another thread!

[@ShopperPlug]

@@AllTradesZach Nice.

[@NamasenITN]

Are you aware or other shapes and aspect ratios for similar spring contacts? I struggle to find those in an existing equipment where the spring-part is a small segment and not a tiny ball. Thanks for any suggestion or help.

[@AllTradesZach]

I'm not entirely sure what you mean by "small segment" - just a cylinder? I do see flat faced ones and cone shaped ones on DigiKey, where I got these. Fuzz buttons are another option that can be used similarly.

[@MidhunM94]

Nice Work! What material is used for 3D printing the Fixture? Is it ESD safe?

[@AllTradesZach]

Yeah, it's ESD safe pet-g. It prints really well, but is a bit pricey. I'm considering trying out conductive pla in the future. Of course "ESD safe" is only as safe as the weakest link and I'm often lazy in other areas, but...

[@Aquileoxd3986]

What about the OTA programming?

[@papukaiffa]

You'd need initial program to access OTA feature anyway.. so why double program it?

[@Kysen10]

I just use Tag Connect for programming my STM32 boards

[@saumyacow4435]

So why, if you look a typical electronics supplier (like Mouser) do pogo pins cost upwards of a dollar and regular connectors half that much?

[@FranzTaffner]

What do you have in mind as a software framework for running the tests and shall everything run on the stm?

[@TheRailroad99]

Test engineer here... Depends on your needs. Stand alone testers/programmers can work great for little / cheap boards. Put the board in, it runs a few seconds, then shows / sounds PASS / FAIL. For larger and more expensive Boards with big production runs a full functional tester is often the best solution. It mostly consists of the adapter, some heavy duty 19 inch rack test equipment (Multimeters, scopes, multiplexers) and a PC running specialized software. It gives a full diagnostic of the board, programs it (including serial numbers etc.) and saves the results into a database or ERP system. Most commonly National Instrument's software is used for this (TestStand, LabView, or CVI (which is C with easy GUI functionality)). However at that point it's just a case of PC software preferences. I write most of my test software in C/CVI, others use LabView or Python. TestStand is expensive, but if you can afford it, it does all of the "framework" bits for you ( running test sequences, scanning serial numbers, database logging), you just provide functions that will execute for the test steps. For massive boards ICT is often the best as it can find very specific failures. Flying probe is another option if the production runs aren't that big.

[@satibel]

​@@TheRailroad99another good thing about flying probe is that you can test all the pins without including like 200 pogo pins on the test board.

[@Subgunman]

Built many programming cables using cut off from speaker microphones where the cord set failed. Cheaper to sell the customer a new microphone. I extract the pins and save them for various uses other than programming cables.

[@game-f-un-limitedgamer8958]

Turns out the lower LED response was better for tests 😂

[@xymaryai8283]

i've never used them for this use case, but most other places i've encountered them, in end user and repair contexts, they've had issues that infuriated me. my current wireless earbuds use a particularly bad design that the predecessors didn't, meaning i can't trust them to charge for when i need them. after a string of other failures with earbuds, its quite annoying that such expensive sets have so many issues, and incorrectly used pogo pins might be the final straw for me to somehow find wired noise cancelling earbuds, or just fix my over-ear headphones.

[@MinZhang-b4m]

Wow I didn't realize I had these in my headphones too. Never had an issue with my first pair I use daily since 2021, Galaxy buds+ still have the 11hr battery too. Might be a design problem with your headphones, mine are perfectly spaced and never had an issue.

[@mph8759]

4:10 it is my first time watching!

[@CarlosRuiz-cn6wh]

What kind of solder stencil fixture is that? Is it custom made with micropositioners?

[@AllTradesZach]

I designed and printed it myself using an xyzr stage. There's a whole video on it! The stage adjustment is great, but the 3d printed frame isn't quite stiff enough, so I might reprint it at some point.

[@jrstf]

I hadn't heard of pogo pin targets before. Unfortunately the cost of targets seems to nearly match pins making the cost of pogo pins at least 5 times that of using a standard connector.

[@AllTradesZach]

The solder cup ones make a lot of sense if you're building a custom pogo connector, but otherwise I agree. PCB pads work for most applications though.

[@OnreinKalfje]

It would help me if you show pictures of what you are talking about, especially in the intro

[@danielbuckman2727]

Awesome 👍

[@GameDesignerJDG]

Great video! I'm now a convert to pogo pins and a new subscriber. But I have a major complaint. Please don't purposefully play a loud tone in a KZbin video. 13:06 I get why you're doing it IRL, and I get that it's probably edited to be way quieter than it actually was, but it should be as quiet as someone whispering, if audible at all. It should *never* be louder than the person who's talking (since the person listening needs to have the volume be at a level that that person can be heard at), and you should double check that it isn't louder to people with better hearing than you. We lose our ability to hear regular high pitched tones like that first as we age. That genuinely hurt, so I'd be very grateful if you didn't do it again.

[@AllTradesZach]

Thank you for the constructive criticism, I'm still quite new at this so any input I can get will help make my content better! If I use a tone like that in the future I'll be sure to quiet it way down.

[@GameDesignerJDG]

@@AllTradesZach Thanks a tonne! It's rare to listen to some random stranger's feedback.

[@kellyaderwa1696]

I subscribed before you asked me to.

[@Abdullu]

13:06 that 440 Hz tone is rather 7494 Hz

[@maxhouseman3129]

You have a lot of non 90 degree traces/junctions in your layout. That could be a potential acid trap, a place where acid during the PCB manufacturing could remain and then destroy your trace slowly over time. For the second LED I would use a small plastic fiber or light pipe, cause your black housing will most probably absorb most of the light even with this strip of mirror tape. Would be also nice to design test equipment that is capable of measuring all parameters without the need of external devices. But as I understood it, that’s your plan for the future.

[@AllTradesZach]

I've not experienced the acid trap issue before, I'll look into that. The active area on the photodiode is very large, so the reflective film actually works well. I've thought about resin printing light guides though. That is indeed the next video, we'll see how well it works!

[@ianchan2624]

Im only using pogo pins is for the single connector to multiple items. They're kinda pricey

[@dieselphiend]

You can get these puppies in 30 ampere.

[@amandahugankiss4110]

no shit? nice.

[@maxhouseman3129]

There exist pins that are rated for over 300 A.

[@dieselphiend]

@@maxhouseman3129 Pogo pins? Are you sure you aren't thinking of bullet connectors?

[@amandahugankiss4110]

@@maxhouseman3129 what would be the use case for a beast such as that?

[@itmepro2389]

Quick charge reusable EMP 🤷‍♂️​@@amandahugankiss4110

[@Schjoenz]

Pogos are illegal in the Philippines.

[@therollo9]

No, not that POGO 😂

[@GimmilFactory]

You said pogo so many times that all I can think of is System of a Down...

[@TatharNuar]

My mouse has an array of 16 of them on the side.

[@InsipidProgrammer]

They're just expensive is all...

[@LoenieMovies]

All nice and well, but aren't you wearing your shirt inside out?

[@kayakMike1000]

Large scale... Bed o' nails.

[@billyjoe3309]

Two words: Native USB

[@FloridaRCFlyer]

Hey Zach, could you post your videos on Odysee as well? Many electronics channels are already on Odysee. Thanks!

[@laurynhoch8915]

I have an idea for a wine rack, DM me

[@bobby9568]

Shizzle channel!

[@D9ID9I]

The problem with people is that everything new is actually forgotten old.

[@omranshahrour7291]

There’s nothing professional and useful about displays in YT, We’d appreciate designing LED display from scratch or doodling with some products and controlling circuits to show images and vids

[@FranzTaffner]

What do you have in mind as a software framework for running the tests and shall everything run on the stm?

[@AllTradesZach]

Probably just bare metal C. I hope to run everything on the STM, but I'm not sure how programming is going to work yet.