Small JTAG connector - Page 1
Forum section: electronics / general

author: stoyanoff
author_rank: Contributor
timestamp: October 31, 2020, 06:50:11 pm
content: Greetings! What type of connector do you use when you need to save space on the PCB? Usually the original JTAG connector is quite big and it has many unneccessary pins. So what connector do you expand to? Something small and easy to plug in/out?Thanks!

author: ataradov
author_rank: Super Contributor
timestamp: October 31, 2020, 09:34:42 pm
content: 10-pin (2x5) 0.05"/1.27mm not shrouded. It is small and has enough pins for everything. The connectors and cabled are cheap enough too.

author: Hideki
author_rank: Frequent Contributor
timestamp: October 31, 2020, 09:49:11 pm
content: A shrouded one likehttps://www.amphenol-icc.com/minitek127-2002122100010c4lf.htmlis easier to plug into, but the unshrouded ones do take up even less space.

author: stoyanoff
author_rank: Contributor
timestamp: November 01, 2020, 07:20:43 am
content: I have this type of expansion, but it`s too big. I was talking about something like dupont connector. I don`t like the duponts particularly, because they are little bit fastidious on pluging in/out. So can you offer something more suitable?

author: ataradov
author_rank: Super Contributor
timestamp: November 01, 2020, 07:25:47 am
content: I'm not sure what you mean by "big". 10-pin 1.27mm connector (like thishttps://www.aliexpress.com/item/32795241952.html) has the same area as 3 standard pins of 0.1" connector.You need to be more specific. If it is actually a full JTAG connector, then you need at least 6 pins, so no connector would be particularly tiny.

author: boB
author_rank: Frequent Contributor
timestamp: November 01, 2020, 07:52:50 am
content: We used a single in-line 50 mil (thousandths of an inch) with 9 pins on one product.Nice and small but not very durable.

author: tszaboo
author_rank: Super Contributor
timestamp: November 01, 2020, 08:00:21 am
content: https://www.tag-connect.comYou buy the cable and the adapter, it is 0 cost on the PCB and quite small.

author: cgroen
author_rank: Unknown
timestamp: November 01, 2020, 08:24:04 am
content: Quote from: NANDBlog on November 01, 2020, 08:00:21 amAgree, we use nothing but the Tag-connect here. We use the "no legs" version with the small clip on the back of the PCB when it needs to stay connected during development, for programming small batches, er just hold the probe to the boards while programming them. 0 cost for the PCB

author: Kjelt
author_rank: Super Contributor
timestamp: November 01, 2020, 08:42:12 am
content: Quote from: ataradov on October 31, 2020, 09:34:42 pmI second this but do mark the 1 pin or side of the connector on the pcb since the only downside is that it is symmetrical and you can connect it wrong potentially damaging the target.

author: ataradov
author_rank: Super Contributor
timestamp: November 01, 2020, 08:46:33 am
content: Quote from: Kjelt on November 01, 2020, 08:42:12 amYes, sure.But for a standard ARM Cortex debug connector layout is such that reversal does not really cause any damage to the target or debugger. Most the time when there is no marking, I just plug it in whatever random way and just check if it works.

author: ElektroQuark
author_rank: Unknown
timestamp: November 01, 2020, 09:54:58 am
content: I use this reference from SANTEC: FTSH-105-01-L-DV

author: Fred27
author_rank: Unknown
timestamp: November 01, 2020, 10:38:31 am
content: Quote from: ataradovI have found out the hard way that it can cause damage if you clumsily misalign it though.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 02, 2020, 04:22:09 am
content: Quote from: NANDBlog on November 01, 2020, 08:00:21 amYou lose the cable or break it...In addition, your entire PCB must be covered with immersion gold, HASL may suffer after a while, when you may need to connect.

author: stoyanoff
author_rank: Contributor
timestamp: November 02, 2020, 06:01:09 am
content: Thanks for the answers! I am using TI F280041C. So I agree with S. Petrukhin. this Tag connector looks nice, but in time it can cause problems i think. So I decided to make a simple bridge with ribon cable from the XDS110 output to HN terminal I`ll see how many pins. They will be in 1 row and I think they are going to take less space. I`ll try different approches here and see what is going to happen as a result.Thanks!

author: exmadscientist
author_rank: Frequent Contributor
timestamp: November 02, 2020, 06:46:07 am
content: The XDS connector series's cTI 20-pin connector is not arbitrarily pinned out. I'd advise you not to mess with it. It's already 0.050" pitch, so there isn't much space to be saved there. (Some, to be fair.) Most of your space savings will come from eliminating pins, and the best bets for that are the higher EMU pins and such, as they are only used by the more expensive processor lines. The extra grounds probably ought to stay, since the clock on these things can go pretty high.If you're using the older coarse-pitch 14-pin header, switching to the 20-pin would be smaller and slightly more expensive.

author: tszaboo
author_rank: Super Contributor
timestamp: November 02, 2020, 07:35:47 am
content: Quote from: S. Petrukhin on November 02, 2020, 04:22:09 amThen you buy another one? Same as with the regular JTAG cables. The surface finish doesnt really matter, it puts enough force on the probes to overcome this.

author: Fred27
author_rank: Unknown
timestamp: November 02, 2020, 08:23:40 am
content: I've used TagConnect with the cheapest boards from the usual Chinese board houses and not had a problem.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 02, 2020, 05:42:49 pm
content: Quote from: NANDBlog on November 02, 2020, 07:35:47 amIn Russia, this cable costs half the cost of a good programmer with WiFi and has a long delivery time.I bought these pins from my Chinese friends. They are very cheap compatible with holes for regular IDC studs. I think I'll make my own connector from them, which connects to the usual through hole for IDC. I don't like IDC studs just because they are difficult to mask when varnishing the PCB.

author: NorthGuy
author_rank: Super Contributor
timestamp: November 03, 2020, 02:08:05 am
content: Quote from: blueskull on November 03, 2020, 01:42:42 amI solder pogo pins through hole, using two identical boards spaced about 10 mm apart. I use them hand-held for programming, testing and such. You can even latch them under something to free your hands and do debugging.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 03, 2020, 02:24:03 am
content: Quote from: ElektroQuark on November 01, 2020, 09:54:58 amYeah. Have used that kind of stuff before, but I don't anymore. I'll favor the same in TH version if possible. Those SMD connectors break pretty easily.But pogo pins are frankly the best if available area is at a premium IMHO.

author: lucazader
author_rank: Regular Contributor
timestamp: November 03, 2020, 07:33:45 am
content: At work we have switched over to using a small 10-way FFC connector. Pipe out the SWD pins as well as a debug uart and some other useful signals in a "standard to our company" way.Works for us and usually you can slip the ffc cable out of a fully assembled product if one needs to.Cables are dirt cheap, as are the connectors.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 03, 2020, 08:05:16 am
content: Quote from: blueskull on November 03, 2020, 01:42:42 amGuys in China do everything instantly and sell on Aliexpress. But the clothespin is inconvenient for the board installed in the case.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 03, 2020, 08:10:17 am
content: Quote from: lucazader on November 03, 2020, 07:33:45 amGood solution. But these cables are short and weak. If only used from the printer head. And you probably made an adapter from this tape to the IDC output of the programmer?

author: lucazader
author_rank: Regular Contributor
timestamp: November 03, 2020, 08:54:01 am
content: Quote from: S. Petrukhin on November 03, 2020, 08:10:17 amWeak, not really. A cable usually last for around a year of daily use, even being slightly crushed between housing parting lines doesn't really affect their overall longevityAnd since they are soo cheap, we just buy 50 or so at a time so it doesn't really matter if the cables occasionally break.Short, also not really, you can get them in many different lengths, we often get around 30-50cm ones.But yes we also have an adapter board that has the standard 10 pin arm connector, along with 2.54mm headers and other things we find useful. super easy to put together and just requires a very quick turn around 2 layer board from a cheap pcb manufacturer.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 03, 2020, 09:28:52 am
content: Quote from: lucazader on November 03, 2020, 08:54:01 amYes, you have a convenient system for your needs.But I decided to abandon even the FPC for connecting the circuit boards. They have a very small pitch / gap. My devices work in an aggressive environment and there are cases of damage to the case, moisture ingress. The board is varnished and does not suffer, but FPC get electrochemical corrosion very quickly - they like to collect drops on themselves. The 2.54 mm gap on the IDC is not so dangerous and the thickness of the pins will not allow corrosion to destroy them. Even bare holes for IDC are more stable - drops of moisture can not stretch between them as a solid bridge.

author: MarkR42
author_rank: Regular Contributor
timestamp: November 12, 2020, 10:02:54 am
content: I'm a bit late to this thread...If you can put the connection at the edge of a PCB, use the amazing soicbitehttps://github.com/SimonMerrett/SOICbitewhich has a BOM cost of $0 and the test-clip is very cheap indeed.It works reliably for me (not for JTAG, for other protocols) and has 8 connections, enough for a typical jtag.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: November 12, 2020, 09:18:33 pm
content: Quote from: S. Petrukhin on November 03, 2020, 08:05:16 amOoh, they also have the "Goldilocks" 1.5 mm pitch clips! Metric and large enough to comfortably route a trace between neighbouring through-holes.https://www.aliexpress.com/item/1005001419056138.html(note: new seller, no feedback)https://www.aliexpress.com/item/4000852156565.html

author: aandrew
author_rank: Frequent Contributor
timestamp: November 13, 2020, 12:33:15 am
content: 0.050" 2x5 is the way to go. shrouded or non, depending on size.Stay the hell away from that garbage tag-connect. If you want to actually debug with one of those you either have to use the retainer clip, which works loose over time and drives you mad with frustration, or you use the one with the plastic "clip" feature that needs four gigantic holes around the copper pads to grab on to, negating any advantage over the absolutely bog-standard 2x5, 0.050" header. Save your money and avoid that bullshit.If you really want a zero PCB cost solution, use something like isptouch (https://github.com/daspilker/ISPtouch,unfortunately the page showing the pic has gone 404 but luckily web archive has it:https://web.archive.org/web/20170719050318/http://www.daniel-spilker.com/blog/2011/04/25/isptouch-for-avr-microcontrollers/)Don't give tag-connect your money. it's a non-solution to a problem.

author: ataradov
author_rank: Super Contributor
timestamp: November 13, 2020, 12:42:33 am
content: I don't understand what people are doing with their boards. Why do you need this monstrosity with clips? How do you kill your connectors?When I work on a project, the debugger is plugged in once and stays plugged in for days and weeks. I'd rather have a small flexible cable plugged into a real connector than this clip with pogo pins that gets in a way or everything. Just imagine the nightmare of having to scope probe around that thing.And for more small-batch production I just use a hand-made pogo adapter. This one is for 0.1" spacing. And the board just have pads. It is easy enough to hold it for a couple of seconds while target is programmed.JPEG failed to attach, so PNG instead.

author: Syntax Error
author_rank: Frequent Contributor
timestamp: November 13, 2020, 10:03:39 pm
content: For anyone still left playing at home, you can make a cheap-n-dirty Jtag/SPI probe from an IDC header and 1mm diameter P100 pogo pins. First, you need to chase out the square holes of the plastic connector with a 0.9mm drill. Then just simply push the pins home. The pins stay held in place. The header can be 6, 8, 10, 12, 20 pins, or whatever. Easy.Pictured, this header was used to land on a row of Mips ejtag solder domes on a router PCB.

author: Kjelt
author_rank: Super Contributor
timestamp: November 29, 2020, 07:38:55 pm
content: Just for information:https://www.allaboutcircuits.com/technical-articles/jtag-connectors-and-interfaces/

author: gmb42
author_rank: Frequent Contributor
timestamp: November 30, 2020, 04:05:37 pm
content: Via Hackaday, another attempt at an edge connector variant:Debug Edge.

author: poorchava
author_rank: Super Contributor
timestamp: November 30, 2020, 07:01:00 pm
content: I use Wurth Elektronik SKEDD IDC connectors. Not small, but I can design a board in such a way, that the debug port is sticking out and is then cut off or broken off in production.Another option that I use is just incorporating it into bed of nails tester and forgetting about the connector altogether.

author: ajb
author_rank: Super Contributor
timestamp: November 30, 2020, 07:29:00 pm
content: Quote from: poorchava on November 30, 2020, 07:01:00 pmYes, I've settled on doing test points as 1.5mm round pads on a 2mm grid, which is a pretty good compromise of density and accessibility. The signals I will want regular access to for development go along one edge so I can solder on a 2mm header, and I use a 2mm stacking header to marshal flying leads into one thing I can plug and unplug from the board easily. I have a handful of squid adapters for SWD, UART, etc that have contacts suitable for the 2mm headers so it's easy to put together a debug harness.That said, I'll still place a 50mil 2x5 SWD header where I can. I've been using a three-hole 100mil header pattern with some kinked pin connectors I made for debug UART, but starting with my next board I think I'll put debug UART signals on a couple of the spare pins on the SWD header.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 05, 2020, 03:11:23 am
content: Quote from: gmb42 on November 30, 2020, 04:05:37 pmNote that edge connectors generally have relatively high insertion force. Also,the 1 mm pitch edge connectorlinked to fromthe Hackaday articleis rated for all offive cycles!Pogo pins are hard to beat for this application.

author: rvalente
author_rank: Frequent Contributor
timestamp: December 14, 2020, 08:45:05 pm
content: I was looking for 2x5 50mil headers on digikey and they are THAT expensive?TMS-105-02-G-Dhttps://br.mouser.com/ProductDetail/Samtec/TMS-105-02-G-D?qs=0lQeLiL1qyaWqHDjJyuw0g%3D%3D$1.17 is little to much for such a simple mass produced thing

author: ataradov
author_rank: Super Contributor
timestamp: December 14, 2020, 08:47:05 pm
content: All connectors on DK and such are overpriced.Direct from China will give you much better prices. And connectors are not that high tech to screw up.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 15, 2020, 09:30:59 am
content: Quote from: poorchava on November 30, 2020, 07:01:00 pmHow long have you been using them? How many connections can they withstand?I ordered a sample pn 490107670612 - it looks very good.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 19, 2020, 11:37:48 pm
content: Wurth Elektronik SKEDD IDC came to me. A very good connector, definitely. Gold-plated contacts of an interesting shape. But I am sure that this connector cannot be used as a basis for test connections and programming. The pins are very tight in the holes, this is not designed for multiple connections - they will simply tear the metallization at the edges of the hole. Once or twice, I think, normally, no more.But i immediately tried to cross the snake and the hedgehog: installed pogo pins. It didn't work out. First, pogo pins of the E format didn't fit-their heads stick out, and the connector should sit close. Pogo pins of the F format with the absence of a head also did not fit - plastic guides have a fixing protrusion and it is very weak, 8 pogo pins push out the connector with their springs.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 06, 2021, 09:44:28 am
content: I like the model of the tag-connect connectors but am offended by their price.If you put test pads on your PCB and some aligning holes similar to the tag-connect idea and the holes are on a 4.54mm grid then you can easily make a test adapter from two pieces of matrix board, a few pogo pins and some stiff wires to align it through the holes.

author: IDEngineer
author_rank: Super Contributor
timestamp: January 10, 2021, 05:01:06 pm
content: I don't understand all the hate for Tag-Connect. We've been using them for years here, both for R&D and Production. They last almost forever, and if you use the "legless" versions they consume very little space on the board. Yes, they cost a few bucks, but as noted they last a very long time (I don't remember ever discarding one) so it's basically a one-time tooling cost. We just purchased two more of a particular version of the "legged" variety and I think they were $36 from DigiKey. Normally we order direct from Tag-Connect but we had an R&D order going in to DigiKey anyway so it was just easier and likely faster.I do concede that the retaining clips for the "legless" versions wear out with repeated insertion cycles. We've never discarded one that I know of but we do have one of the original metal ones whose retention is starting to weaken. That said, I still use it every day (which is how I know about its status) and it's still working for my needs. I can imagine discarding it in a few more months but they cost what, $5? For 5+ years of daily R&D use that's not bad.Yes, we could make something similar on our own. But for $36 over a lifespan of at least five years, why bother? That's not a good use of personnel time.

author: gussy
author_rank: Contributor
timestamp: January 11, 2021, 04:43:50 am
content: Try using the legless version on a product where you can't get the retainer behind the PCBA, or getting a TagConnect cable quickly anywhere in AsiaI've watched a firmware team endlessly fumble with all kinds of contraptions involving rubber bands, tape and weights, to try and get their tag-connects to stay seated. Obviously if you can't use the retainer, you should use the comically large version with the legs that always snap off, but the previous EE was set on tag-connect and didn't have space for the holes (and the legs always snap off anyway).After I joined and watched them struggle for a few months, then with the next revision of our boards I switched back to the standard 1.27mm pitch SWD connector, and every firmware engineer there thanked me.Support from TagConnect is also quite terrible. It looks like someone came up with the idea 12 years ago then checked out and now it's their retirement income stream. The website looks like it hasn't been updated in years and is a mess to navigate. Want to download some footprints? Surely a company that makes connectors supplies footprints? Of course they do, in a zip file called "CHECK_CAREFULLY_AGAINST_TAG-CONNECT_SPEC_AND_USE_AT_YOUR_OWN_RISK.zip" inside another folder named "CHECK CAREFULLY AGAINST TAG-CONNECT SPEC AND USE AT YOUR OWN RISK". Want an Altium footprint? Sure, just choose one of the ~12 different implementations inside that zip folder, but remember to use them at your own risk. Should you use the "TC2050-IDC" folder, or maybe the "TC2050-IDC probably better" folder? What a joke. I understand that providing footprints for every CAD package is hard, but this is a core part of their business and would take not very much time or money to come up with an official footprint library for all these CAD packages.Like others have said, the idea is good, but the implementation is outdated and needs work. The complacency of TagConnect makes me wonder why some alternative with good worldwide distribution, simple verified footprints and a cheaper price point hasn't been created? Probably because most people designing high-volume products just use the standard connectors

author: IDEngineer
author_rank: Super Contributor
timestamp: January 11, 2021, 07:11:24 am
content: With all due respect, that is diametrically opposite of my experience with them. I've had a few questions along the way and when I've called them I've ended up talking with the folks actually designing their products, in some cases even being sent prototype drawings of not-yet-released products. We're a small company and don't buy that much so it's not like we get special treatment.I'm sorry you're having such bad experience with them but I feel like I need to say it's not always like that. I can't explain the difference but what you're describing sounds nothing like the company I've dealt with. I guess YMMV.

author: gussy
author_rank: Contributor
timestamp: January 11, 2021, 07:52:28 am
content: Of course. These are just my own experiences and I'm sure others like yourself have had nothing but good experiences. Like you say YMMV. For what it's worth, I was a huge fan of the product for personal projects until I started using it in production on high volume products, then I got burnt and saw others frustrated with them on a daily basis.My comments about support mostly surround the laughable zip file of footprints they provide. Providing 12 to 15 different Altium footprints for the same connector and going as far as to label one as "probably better" is unacceptable IMO. It would be better if they provided no footprints instead of the confusion that is offered up. They're running a business, I assume/hope they make good margin on their products, they could hire some contractors to create verified footprints in every CAD package they can think of and I doubt it would cost very much. Not doing so and providing these crowdsourced unverified footprints just makes the whole outfit look unprofessional.In our case at work we likely saved (insignificant amounts of) money by moving away from tag-connect. $40-50 per cable plus a spare or two for 10 firmware+test engineers every 6 months buys you a lot of 2x5 pin headers.

author: tszaboo
author_rank: Super Contributor
timestamp: January 11, 2021, 11:32:19 pm
content: TagConnect is a small family business. Yes, it costs more than making the cables, because they live by selling these. Feel free to copy it and market it, I'm sure its not rocket science, see how your business goes.They dont have Altium, probably the footprint was someone's own contribution, free of charge. You can order it from Digikey. It works, we programmed thousands of boards with one cable without replacing it. What else do you want? If you dont like it, simple, there are other connectors.

author: jnz
author_rank: Frequent Contributor
timestamp: January 12, 2021, 09:19:52 am
content: Another tag connect here. Just do it, be cool like us.

author: fcb
author_rank: Super Contributor
timestamp: January 12, 2021, 09:50:42 am
content: We've been using TagConnect since it was introduced. Bloody brilliant. Still using the original TagConnect cables, and have done countless designs for us and clients using them. Zero problems. Zilch.We use both the latched (for development and if we've got space) and latchless designs (usually for production and tight boards). As for cost - irrelevant, they've got to eat too. Never damaged an electrical pin, stainless guide pin or latch-leg.

author: Bassman59
author_rank: Super Contributor
timestamp: January 13, 2021, 11:08:29 pm
content: Quote from: gussy on January 11, 2021, 07:52:28 amHow hard is it to make a footprint in your preferred EDA package?

author: IDEngineer
author_rank: Super Contributor
timestamp: January 13, 2021, 11:39:01 pm
content: Can't be that hard. Our PCB Designer did it in about five minutes. When we first started looking into these connectors and I asked him about getting the footprint he said "Already finished."EDIT: And to be honest, creating footprints is just a part of the business these days. There are plenty of "standard" footprints out there but manufacturers seem to feel no loyalty to them. We just got burned by that again on our last board... the spec sheet description claimed it was a "standard 8-SOIC" so our designer just grabbed that footprint from the library, but when the boards got to the pick-and-place guys they said "Umm, this isn't a standard". And they were right. We have a new policy now, we review ALL footprints no matter what the spec sheets claim. Just another part of doing business. So having to create a footprint for a program/debug connector is really a non-event.

author: Bassman59
author_rank: Super Contributor
timestamp: January 13, 2021, 11:51:56 pm
content: Quote from: IDEngineer on January 13, 2021, 11:39:01 pmI should say that I just did a small board with the legged TagConnect. One of the Kicad librarians had created a series of TagConnect footprints, one for each size (2030, 2050, 2070) with the legs, and one set without. There's also one for the 2050 that has a keep-out on the bottom layer for their funny retaining clip thing. I checked the 2050 I used against the data sheet drawing and saw that it matched, and the board works.I think next time I'll go with the no-legs version and get the bottom clip. The legs break too easily, which is my only complaint.

author: IDEngineer
author_rank: Super Contributor
timestamp: January 13, 2021, 11:54:57 pm
content: Yeah, we favor the legless version most of the time. But I just spec'd the legged version on our most recent board, ironically because things are tight and getting the connector in and out will be a PITA. This way once it's snapped in, it will stay until we intentionally remove it. It's also a board that gets installed into a potting box with corner screws so accessing the back for a retaining clip will not be convenient. The legged version was the perfect solution.

author: gussy
author_rank: Contributor
timestamp: January 14, 2021, 01:52:31 am
content: Quote from: Bassman59 on January 13, 2021, 11:08:29 pmIt's not hard? I make all my footprints regardless, but the problem is what's provided is worse than useful, it's confusing. Yes I'm sure they don't have Altium and every other CAD package, but they probably also don't draw their own copper wires or make their own injection molding tooling in-house, but they pay someone to do it, because they're a business. How much would it cost for a few hours of a contractors time to make an official verified footprint for a dozen of the most popular CAD packages? I'd say less than $1k even at US rates. Is there not enough margin to invest in high quality documentation and supporting footprints? That's my point.To be clear I'm not saying theyhaveto supply footprints, lots of connector vendors don't, but if they do supply something it should be verified and correct. Imagine if Molex supplied 15 Altium footprints for a connector and labeled some as "probably better"FWIW someone further up the thread said they didn't understand the hate for TagConnect. I'm just answering the question of why some people don't like it. It's clear some people here like it, and I can think of at least a dozen collogues who don't like it. YMMV, use whatever works for you.

author: jnz
author_rank: Frequent Contributor
timestamp: January 14, 2021, 04:49:58 am
content: The tag connect footprint is extremely easy. The hard part I’ve found is if you are using the leg version, that unless you go tiny with your vias and traces that you may have a tough time routing the 10 pin version in some scenarios.... fan it out a little before you start.

author: Bassman59
author_rank: Super Contributor
timestamp: January 14, 2021, 06:45:55 pm
content: Quote from: jnz on January 14, 2021, 04:49:58 amTrue! The thing I just did with the legged 2050 was an SiLabs micro with the C2 interface, so it used pins in the middle of the connector. Getting around the leg holes is a challenge because of their size.

author: bson
author_rank: Unknown
timestamp: January 15, 2021, 07:59:31 pm
content: Quote from: IDEngineer on January 13, 2021, 11:39:01 pmYeah, agreed. What I do is print the footprint at 1:1 on a laser printer and check under a microscope with the actual part. Nothing makes one feel dumber than getting a board and finding out a footprint isn't right!The laser printer is surprisingly accurate dimensionally, and works well down to 0.5mm pitch parts. The worst offenders are custom shape QFNs, with oddities like specifying distance from the package center to outside the last pad and the space between pads but the pad width itself needs calculation. Human math is always error prone and making a mistake when juggling dimensions is surprisingly easy. It only takes a minute or two to actually check though.

author: poorchava
author_rank: Super Contributor
timestamp: January 18, 2021, 08:02:52 pm
content: I hate the 1.27 pitch connectors. Expensive, easy to damage, cables are expensive from normal sources (not AliExpress).I use Wurth Elektronik's SKEDD. For STM32 a 6 pin fits nicely with STLink that is found on Nucleo boards. I work mainly power electronics nowadays, so debug probes are largely a consumable item.For C2000 i just use bigger variety of SKEDD.If space is at premium, then a few cias for poppins are enough. You can solder magnet wire to them for development.

author: ajb
author_rank: Super Contributor
timestamp: January 21, 2021, 03:44:04 am
content: Quote from: poorchava on January 18, 2021, 08:02:52 pmI've started just buying the bare cable and connectors. $7 for 10ft/~3m of cable and about a buck each for the connectors, and I can make any length/orientation I want. All of the 50mil IDC connectors I've seen have pretty close guides for the cable so they're very easy to install. The connectors can work loose over time, apparently due to the latches that hold the connector closed around the cable wearing, so I've tried a dab of super glue on the ends of the latches on a recent set of cables as an experiment, we'll see what happens over time. I haven't had a cable fail due to anything else, and I tend to abuse them a fair bitcable:https://www.digikey.com/en/products/detail/3m/3756-10-100/5308218connectors:https://www.digikey.com/en/products/detail/cnc-tech/3230-10-0101-00/3883465

author: gussy
author_rank: Contributor
timestamp: January 22, 2021, 12:00:56 am
content: Quote from: poorchava on January 18, 2021, 08:02:52 pmIt depends on what your idea of expensive is, but these are relatively economical and easy to source at $2.95https://www.digikey.com/en/products/detail/adafruit-industries-llc/1675/6827142Almost as cheap as building your own cables with the links above, though if you need custom lengths then building your own is a good option.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 17, 2021, 10:39:12 am
content: Let's update the topic bit.Friends, I found a good connector. It is similar in principle to the Tags-Connector and Wurth Elektronik ASKED IDC: it is attached to the bare holes in the board, but unlike the others, it has retainers.Not thin plastic teeth hold it on the board, which will eventually be wiped off, but there is a retainer.I chose 8 pins (2x4), there are 2 rows of options from 2 to 8 pins each (4-16 in total).Called: PCB direct plug, Push-in spring connection, Patch: 3.5 mmType: SDHC 1.5/4-PV-3.5Number of contacts: 2 rows in each 4Catalog code: 1848668https://www.phoenixcontact.com/online/portal/ru?uri=pxc-oc-itemdetail:pid=1848668

author: tszaboo
author_rank: Super Contributor
timestamp: February 17, 2021, 03:19:26 pm
content: Quote from: S. Petrukhin on February 17, 2021, 10:39:12 amSmall connector: 21mmx 17mm x 13mm.You know, we used to have this joke:"- Why isn't there any microelectronics production in russia?- It doesnt fit through the factory door."

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 17, 2021, 05:00:05 pm
content: Quote from: NANDBlog on February 17, 2021, 03:19:26 pmYes, it is quite bulky and is unacceptable for compact devices. But for my industrial design, it is quite applicable, not much more than the usual IDC. I will try to use it in the next device.

author: harerod
author_rank: Frequent Contributor
timestamp: February 17, 2021, 07:58:47 pm
content: Quote from: Bassman59 on January 14, 2021, 07:45:55 pm>Quote from: jnz on January 14, 2021, 05:49:58 amTrue! The thing I just did with the legged 2050 was an SiLabs micro with the C2 interface, so it used pins in the middle of the connector. Getting around the leg holes is a challenge because of their size.* * * *I've been using the TC2050-IDC for years and on dozens of designs. For the escape routing I use 150µm traces. The distance between the guide holes and those traces violates my normal design rules, but I have never had any issues programming a controller.Since the programming interface is used during initial programming, advanced trouble shooting and for development, the reliability of those traces is not that critical.I find the TagConnect a great solution that doesn't incur a per board cost. Not having a header (a.k.a. antenna) on the board is a nice bonus regarding EMC.I have been using the same TC2050-IDC-cable for years, no stability problems. Applications are mostly JTAG, low current power supply, serial interfaces, etc..My customers' manufacturing operatives seem to break the clamps on occasion. Therefore, when programming only, the TC2050-IDC-NL, which is being held down during communication, is a good option. When handled correctly, there is minimal wear on the TagConnect.For fully automated mass production a board would feature additional pins, which are contacted by a bed of nails type test adapter.