Looking for high cortex swd connector - Page 1
Forum section: electronics / projects

author: Jeroen3
author_rank: Super Contributor
timestamp: July 25, 2017, 09:37:34 am
content: I'm looking for anhighCortex SWD connector, it has to protrude the +/- 5mm of potting. For those unfamiliar, the cortex debug connector is a 2x5 pin 1.27mm pitch IDC style connector.I have found so far, normal use: FTSH-105-01-L-DV-K, which I particularly like because it is very compact. See image attached.And the high version I have found do not offer shrouding, thus are subject to wrong insertion. eg: FW-05-03-L-D-235-100I asked Samtec about a raised FTSH, but they can only do a raised SHF as custom part. Which is twice as wide and $$$, for a part used <10 times.An ideal solution would be to not have the cortex debug connector at all, and just use pogo pins to flash an initial bootloader. But, there is no bootloader yet.Plus, if the bootloader fails, it will literally be a brick until you have dug out the potting. Too expensive gamble (now). (low quantity, high value products)Who has the connector I want?

author: mikerj
author_rank: Super Contributor
timestamp: July 25, 2017, 10:03:09 am
content: The Cortex debug header should be keyed by removing pin 7 and having a blanking pin in the female half, so there should be no problems with getting the insertion wrong.

author: ataradov
author_rank: Super Contributor
timestamp: July 25, 2017, 04:56:32 pm
content: And the wrong insertion does not really damage anything anyway, so I don't see the problem. Keying is not a thing, since none of the debuggers I've seen have key pin blocked in the connector.

author: Jeroen3
author_rank: Super Contributor
timestamp: July 26, 2017, 05:30:46 am
content: You're right about keying. But the programmers just use generic cables that do not have keying. This can be fixed of course.

author: ataradov
author_rank: Super Contributor
timestamp: July 26, 2017, 05:34:41 am
content: Depending on your quantities, you can also try to use shrouded connectors. They are hermetical, except for the key hole on the side. If your volumes are not too high, you can cover this hole with a piece of tape or something like that. This way your connector will be flush with the potting.Like this:http://www.ebay.com/itm/50Pcs-1-27mm-Pitch-2x5Pin-10-Pin-Straight-Male-Shrouded-Box-Header-IDC-Connector/172311876365.They are 4.5 mm tall.Or just bring out 3 pins (or all of them if you want) on a 0.1" connector.

author: Jeroen3
author_rank: Super Contributor
timestamp: July 26, 2017, 06:45:19 am
content: We have found one manufacturor of raised 2.54mm 2x5 IDC. It's on the 8 bit products.But this box header is large, I'd hoped to find a smaller one.I think I have to go with the unshrouded connector. Because indeed, as you've mentioned, connecting it reversed does not cause damage.

author: krho
author_rank: Regular Contributor
timestamp: July 26, 2017, 03:54:24 pm
content: Tag connect?

author: ataradov
author_rank: Super Contributor
timestamp: July 26, 2017, 04:03:48 pm
content: Quote from: krho on July 26, 2017, 03:54:24 pmWhat it is going to do in this case? The board is potted. Tag connect here is even more useless than it normally is.

author: Kjelt
author_rank: Super Contributor
timestamp: July 26, 2017, 05:44:21 pm
content: Just thinking out of the box, if it is low quantity you could think of- mount a female connector and insert a double row male (extender) before potting- mount a so called P&P guide these plasticks stick on top of the male pins so the p&p machine can handle the parts. Pot the pcb and just before the potting material becomes too hard remove the placing guide and your pins are in the clear. Perhaps you need to create special guides that cover the pins from all sides.- use a custom connector that is heigh enough and build converter cable for the programmers. In my company we had a lot of pcb edge connectors since they cost no money, it was a PITA because for reprogramming we had to file off the solder mask from the pcbsnot recommended.

author: Jeroen3
author_rank: Super Contributor
timestamp: July 27, 2017, 06:20:21 am
content: The potting compound has a wicking effect (capillary action), any female boxheader must be hermetically sealed on the bottom.These do not exist.Years of experience has discovered that you cannot rely on the potting company to do such manual actions reliably.You have to deliver the product mold-ready otherwise you will get malformed products == lost revenue.A tag connect or edge connector could work during initial testing and rely on the bootloader later on.There is no bootloader. I have even considered an edge connector protrude from the potting on the side, but this is only possible with rubber molds, but the edges of rubber molded products look awful, uneven and wavy.

author: ataradov
author_rank: Super Contributor
timestamp: July 27, 2017, 06:22:27 am
content: I still don't see why you can't put male connectors. Pick long 0.1" male connectors (they do exist) and you will be done.

author: ataradov
author_rank: Super Contributor
timestamp: July 27, 2017, 06:23:47 am
content: Also, is there already existing interface to the device? SWD pins can be safely combined with GPIO pins in a lot of cases.

author: Jeroen3
author_rank: Super Contributor
timestamp: July 27, 2017, 07:02:39 am
content: These are long male connectors. FW-05-03-L-D-235-100

author: krho
author_rank: Regular Contributor
timestamp: July 27, 2017, 04:29:34 pm
content: Quote from: ataradov on July 26, 2017, 04:03:48 pmSorry non native speaker and have missed the potting in the OP post.

author: colorado.rob
author_rank: Frequent Contributor
timestamp: July 27, 2017, 05:24:14 pm
content: It seems to me that you just put in test pads that can be reached via pogo pin and wall off the area before potting with a small, 3D-printed part. In effect, that's all a tall connector is doing for you -- walling off the potting from the SWD.