Author Topic: Tag-Connect Edge-Connect  (Read 3919 times)

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Offline julianhigginson

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Re: Tag-Connect Edge-Connect
« Reply #25 on: April 03, 2019, 06:51:12 am »
I like that peg idea! it's pretty cool. What do you use for the pogo pin spacing? (I guess it's that light blue plastic bit ? what's that?)

But I'm not really sure this is a suitable solution if you're a development contractor - sitting down to build these on contracting rate time, and needing to explain to other people (client maybe, or any other subcontractors they engaged) how to use it and how to build their own.. hourly rate for all of that and you could buy a big box of tag-connect cables, I think. :-)

Also, since you have holes in the PCB already for this approach, you could probably do almost as well with a plain long pin header run through the holes and pushed at an angle... use the weight of the PCB to hold it in place.
 

Online IDEngineer

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Re: Tag-Connect Edge-Connect
« Reply #26 on: April 07, 2019, 02:32:24 pm »
We use a LOT of Tag Connect's traditional connectors in production here. Very happy with them. Clever idea, well executed.

We looked very seriously at using that EC style, I even had a nice conversation with the owner/inventor at the company, but ultimately abandoned it. We sent their spec sheet to several PCB shops that we use and every one warned of cost and QC concerns. My interpretation of that was they had just given themselves an "out" if things went wrong down the road... "We warned you, but you insisted, and now here we are."

What I'd like to see (but haven't shared with them yet) is an inline version of their standard connector. Instead of two rows of pins and contacts, just a single row. This would give you a long, narrow form factor that would fit better in a lot of PCB layouts than their present, more squarish footprint.
 

Offline SiliconWizard

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Re: Tag-Connect Edge-Connect
« Reply #27 on: April 07, 2019, 06:47:20 pm »
What do you use for the pogo pin spacing? (I guess it's that light blue plastic bit ? what's that?)

It's probably just based on something like that:
https://www.ebay.com/itm/Spring-Loaded-Pogo-Pins-Receptacles-for-Jtag/250546684662
https://www.ebay.com/itm/Spring-Loaded-Pogo-Pin-Adapter-for-Jtag-cable-pitch-0-1-2-54mm/260430819053

you can find many variants of those on eBay, Aliexpress, etc. I have a few and that's handy.
 
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Offline bson

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Re: Tag-Connect Edge-Connect
« Reply #28 on: April 07, 2019, 08:25:51 pm »
We use a LOT of Tag Connect's traditional connectors in production here. Very happy with them. Clever idea, well executed.
I created an adapter that goes from the 10-pin .050" Cortex-M connector to RJ12 for TC2030 - for SWD/SWV only.  I've been thinking of extending this to a small box that detects VCC on the target, lights a LED on the enclosure, and either after a brief timeout to ensure a good connection (like maybe 500-750ms), or when a button is pushed, issues a text message on a USB VCP connection to let a USB host know it's plugged in.  The host can then run a programming command, or grab a complete system state dump for post-mortem.  This would permit using the legless TC2030-NL without the little gripper for programming - just push it in and hold it there, wait for the adapter box LED to come on, the host to begin programming, verification, test, and done.  Disconnect and power off; ship it!  Something to program small volumes, maybe in the 100s, that just about anyone can handle.  Glitched or had a problem?  Just do it again.
 

Online IDEngineer

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Re: Tag-Connect Edge-Connect
« Reply #29 on: April 07, 2019, 09:40:35 pm »
I created an adapter that goes from the 10-pin .050" Cortex-M connector to RJ12 for TC2030 - for SWD/SWV only.  I've been thinking of extending this to a small box that detects VCC on the target, lights a LED on the enclosure, and either after a brief timeout to ensure a good connection (like maybe 500-750ms), or when a button is pushed, issues a text message on a USB VCP connection to let a USB host know it's plugged in.  The host can then run a programming command, or grab a complete system state dump for post-mortem.  This would permit using the legless TC2030-NL without the little gripper for programming - just push it in and hold it there, wait for the adapter box LED to come on, the host to begin programming, verification, test, and done.  Disconnect and power off; ship it!  Something to program small volumes, maybe in the 100s, that just about anyone can handle.
We toured a manufacturing facility in Shenzhen China that had built something like that in-house. They panelized multiple PCB's, and after stuffing but before they separated them they put them into this fixture that had X-Y control with a programming connector on it. The operator pushed a single button, and the X-Y moved the connector around the panel to each of the footprints. When it lowered and made contact, it detected the voltage on the pins and triggered the programmer. It moved around, picked up all boards on that panel, and then signaled it was done. It felt like a bit more automation than was necessary (given the low labor costs there) but they did a nice job of it... definitely homebrew but worked great.
 

Offline KL27x

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Re: Tag-Connect Edge-Connect
« Reply #30 on: April 07, 2019, 10:18:54 pm »
^I custom programmed a CNC machine to do that. i programmed thousands of boards with it. I gave the firmware a "wookie wiggle" option, for the time I accidentally ordered boards with paste layer on the ICSP pads, so that the serrated pins would dig through the flux residue and/or oxide layer.

Quote
When it lowered and made contact, it detected the voltage on the pins and triggered the programmer.
I just programmed mine to start flashing after lowering the Z axis. And it moves to the next position after receiving a programming verify, so on error it stops and waits for human intervention. I actually made my own controller from scratch. Just a micro and transistors to move the steppers in a grid/array, adjustable for number of rows and columns, X and Y travel, an input for programming verify, and an output to trigger the programmer. There is a start button and a clear/home/abort.

But ultimately, if just doing ICSP (not board/assembly diagnostics) I found it is much easier to flash the bare chips. Except for stupid QFP's, it is much easier and compact to handle chips than panels of boards. This means you can load a crapton of chips at a time, vs loading a CNC machine with panels of say 12-30 boards, every 5 or 10 minutes, all day. And there is less tolerance stacking to bother about if you can design a machine mechanism to program bare chips vs boards. You don't need optical correction or whatnot. I flash my own DIP gullwing down to SOP and even QFN chips. The latter is a bugger to get dialed in, initially, but once that is over, I have never had to fidget with the mechanism, again. It requires some extensive setup time to add a new chip or even pinout to the system, but it's good for medium volume use without paying 10 cents per for the privilege and allowing bulk purchases of blank chips vs trying to figure out how many flashed chips to order to get the best price without getting stuck with too many leftover... or discovering a bug or otherwise requiring a firmware update the day your flashed chips arrive. I can just reflash the flashed chips.

This is convenient for me to the point I have ordered boards completely assembled except for the micros. And I hand solder just the flashed micros to the board. This is obviously a bit more work than just flashing assembled boards, but it avoids customs fee of importing microcontrollers from China.

i still put the ICSP header on the PCB, in case of firmware tweaks post-assembly. But I have retired the CNC machine method of programming boards. Too fidgety due to pcb tolerances unless you make the pads rather large. I've pretty much settled on 0.05" pitch pads (same as Tag Connect), and I like to keep it that way for now.
« Last Edit: April 08, 2019, 02:03:58 am by KL27x »
 

Offline PCB.Wiz

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Re: Tag-Connect Edge-Connect
« Reply #31 on: April 08, 2019, 12:58:35 am »
Why use overpriced tag-connect crap when you can just:

.. use a clothes peg (and pogo pins).
Yes, nice example :)
 


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