In a similar vein, I discovered and have started using the Tag-Connect TC2030-USB to program/troubleshoot my boards. While it's technically/originally intended as a way to do JTAG debugging, I am completely enamored with the ability to drop a footprint on my PCB and be able to connect to it without having to place a relatively expensive connector (or a connector at all) that I don't necessarily want users interacting with.
They're fine for one guy using them on the bench but they are a nightmare for mass production. The 50-mil pitch is annoying to make work with a bed-of-nails fixture, the clips are fundamentally incompatible with production lines, either robot or human, the parts are expensive, and the cycle life is not there.
I have had one too many arguments with firmware people who think these things are sufficient for production that I am just done with them by now. There are other ways to do it.
I've been doing a cheap DIY version of Tag-Connect for some STM32 projects (6-pin debug). I just put the holes for a pin header near the edge of the board, and use a pogo clip to connect [0]. (These are readily available on AliExpress in various sizes.)
i wonder how often you can plug/replug the connector in this case. how will the pcb material hold up? with my press-fit or clip-fit (is that a term?) 3d prints, ive noticed that 20 cycles can be sufficient to induce substantial 'loosening'.
That's cool but I am not sure how a customer of mine would feel if I shipped a board to them like that. (I could see trying it on a project for myself, though.)
The problem with USB-C connectors for hobby projects is that they are ass to solder by hand—I’m still looking for one that would use a larger pitch by shorting the four USB pin pairs for either orientation. If you’re shipping something to a customer, I think it’s fair to assume that you don’t really have that problem :)
Do you find the 6-pin charge-only Type-C connectors too small? Or the 16-pin 2.0-only ones? They seem reasonably hand-solder-friendly but I admit I've been fortunate enough to have the factory handling them for me.
Yeah, I find the 16-pin ones a little beyond my skill. They also feel silly—why can’t I have one with just six pins for D±, VBUS, GND, and CC1/2? I guess I could have a factory make a bunch of modules like that for me, but it definitely feels like a thing that should already exist.
(There are passive A-to-C adapters, so I see no reason why I couldn’t short pin pairs like that.)
In a similar vein, I discovered and have started using the Tag-Connect TC2030-USB to program/troubleshoot my boards. While it's technically/originally intended as a way to do JTAG debugging, I am completely enamored with the ability to drop a footprint on my PCB and be able to connect to it without having to place a relatively expensive connector (or a connector at all) that I don't necessarily want users interacting with.
https://www.tag-connect.com/solutions-target-devices/usb-ser...
They have FTDI versions as well, for those who want the full USB boot/reset treatment.
Also, they have another connector for attaching to castellated edges. I think it's just so clever.
I had good experience with carefully spaced holes in PCB and a 50 mil header, see https://jacdac.github.io/jacdac-docs/ddk/firmware/jac-connec...
They're fine for one guy using them on the bench but they are a nightmare for mass production. The 50-mil pitch is annoying to make work with a bed-of-nails fixture, the clips are fundamentally incompatible with production lines, either robot or human, the parts are expensive, and the cycle life is not there.
I have had one too many arguments with firmware people who think these things are sufficient for production that I am just done with them by now. There are other ways to do it.
I've been doing a cheap DIY version of Tag-Connect for some STM32 projects (6-pin debug). I just put the holes for a pin header near the edge of the board, and use a pogo clip to connect [0]. (These are readily available on AliExpress in various sizes.)
[0] https://www.adafruit.com/product/5433
Same, enamored and I’m not even the EE. Elegant, no cost on the product side, and I don’t have to take the board out of the case to access it.
I just use ordinary straight pin headers and stagered via holes. The board just has vias and the cable just has a plain pin header not even pogo pins.
What PCB thickness is optimal? The USB-C tongue on a shieldless part I use is ~0.7mm, which is a pretty thin PCB.
They say "use 0.6 mmm"
https://x.com/AnasYMalas/status/1982060711670067350
That is a very thin PCB. For anyone reading this, 1.6mm is standard.
+copper+ENIG is going to make that 0.7mm
i wonder how often you can plug/replug the connector in this case. how will the pcb material hold up? with my press-fit or clip-fit (is that a term?) 3d prints, ive noticed that 20 cycles can be sufficient to induce substantial 'loosening'.
Plug an OTG cable in and connect to that, so you don't repeat plug-unplug?
What about the force transferred by the connector wiggling? I think You'd need a very good mechanical design on the case to make it all work.
I don't think it's intended for thousands of mating cycles. It's a "free" standard programming/debugging/recovery/configuration interface.
That's cool but I am not sure how a customer of mine would feel if I shipped a board to them like that. (I could see trying it on a project for myself, though.)
The problem with USB-C connectors for hobby projects is that they are ass to solder by hand—I’m still looking for one that would use a larger pitch by shorting the four USB pin pairs for either orientation. If you’re shipping something to a customer, I think it’s fair to assume that you don’t really have that problem :)
Do you find the 6-pin charge-only Type-C connectors too small? Or the 16-pin 2.0-only ones? They seem reasonably hand-solder-friendly but I admit I've been fortunate enough to have the factory handling them for me.
Yeah, I find the 16-pin ones a little beyond my skill. They also feel silly—why can’t I have one with just six pins for D±, VBUS, GND, and CC1/2? I guess I could have a factory make a bunch of modules like that for me, but it definitely feels like a thing that should already exist.
(There are passive A-to-C adapters, so I see no reason why I couldn’t short pin pairs like that.)
If you're interested in other PCB edge connectors, here's an HDMI one I designed:
https://forum.kicad.info/t/hdmi-pcb-edge-connector-for-raspb...