Not too sure where this one should go as I am looking for a product (not asking about a specific product)
Normally most of the things I work with have a easy to find connection, with the most common being the 2.54mm pitch header pins and Dupont style connectors. this is fine as I can make up a cable to match what ever I need.
I am working on a project where the FPGA is on a module board with most of the I/O pins exposed via 1.27mm 2 row headers. As such Im looking for options to allow me to best get a connector to that back to my controller. I can crimp a 2.54mm connector for the microcontroller side, but I cant seem to find much in the way of a 1.27mm crimp kit with “connectors” and housings.
I see there are some ribbon cable to idc style connecters at 1.27mm, but due to the overhang at each end, its not very well suited to connect to a group of pins half way only the header. I could make that work if I only solder in the header pins for that group of I/O pins, but it does not seem like its the right idea?
So now Im looking for ideas.
- Is there a crimp kit for the 1.27mm and housings ?
- I may be able to get away with some 1.27mm IDC headers, but this will most likely have some over hang at the board edge.
any other ideas ?
This is the board (for reference) where the header pins are not yet soldered, allowing me to focuses on the pins I want to use.
I only need two sets of pins connected.
1 will cover 2x4 to supply 5v to that board
The other will be 4-6 Pins which I can really map to any free I/O pins.
thanks for you ideas and thoughts.
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@Michael99645
What a sweet board.
I’d skip the hunt for a Dupont-style but smaller crimp system. They do exist in the wider connector world, but 1.27 mm crimp housings/contacts are usually much less hobby-friendly and not nearly as common as 2.54 mm parts.
Like you said, the most practical option looks like using the 1.27 mm header as a board-level connector, then breaking it out immediately to something easier. For a 2x5 footprint, a SWD 2x5 1.27mm breakout board or a 10-pin 2x5 1.27mm IDC cable / 300mm version is usually the least painful path.
Will you be planning to reuse this board for a lot of projects? If time permits, a smaller adapter board might be worthwhile, but I cant imagine pulling this beast out of all those headers will be particularly easy.
All in all, it looks like this board was developed for a carrier board, where all of the high-speed DDR and PMIC has been handled.
Liam
Thanks Liam
I think you may be right…
The project is really one where the key purpose wont change (i.e. the way it integrates with the world) but the code it is running will.
I will be using a micro-controller to control what happens. It will send the FPGA “config” to the fpga chips volatile memory over jtag (which is working from my controller). Then the controller will send the job details to each board and monitor progress.
The bigger design will support up to 16 of these boards.
I will be using the Atry A7-200 version of the FPGA and these ready to use boards are cheaper then buying the chip itself with everything ready to go as is; just need to work out the best way to connect to it.
My connections will be:
2mm Jtag header to a form of JTAG MUX (for uploading the job config)
1.27mm x 4 pins (they are design for grouping) 5V DC in.
1.27mm x 4 pins for ground.
4 1.27mm jumpers. for setting a board ID.
then 6-8 Pin for my comms.
The boards will just be computing things, not interacting with anything else (i.e. data in computer result out) and I wanted that compute to be scalable.
Hope that kinda makes sense.
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Hi Michael
This could be some search. Especially as there seem to be heaps of “standards” out there. Like every manufacturer does its own thing. Searching through individual manufacturers offerings could me a monumental task.
The best I can think of would be Element 14 who have a pretty good filtering system to narrow the search, closely followed by RS Components. Using these filters you seem to get what you ask for. Not a mixture of items that the vendor THINKS you might want or need. Not like some vendors I can think of.
You don’t have to purchase. I sometimes use these sites to get an idea of what is out there and most importantly EXACTLY what the object is called so i can do a wider search for a vendor (the postage for 1 or 2 items can be prohibitive but the good delivery times can offset this). Years ago it was often thought that if Element 14 (previously Farnell) did not have an item it didn’t exist.
Cheers Bob
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Thanks Rob. yeah, I use Element 14, Digikey and others all the time.
I was really looking for a high level though of people to pick a direction.
I like my tools, but in this case it may be simpler just to find a match set of 1.27mm threw hole bits to solder in where I want them (as I wont be using most of the pins, so it wont really matter if it overlaps one or two each side.
then as already pointed out, just get the ready made lead to suit.
Im roughing in a PCB design to hold the “break out” connectors for the jtag and comms, so I can just add the some connecter to each side i think.
Just making sure Im not over looking something really simple…
Thanks again for the feed back.
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