Alchitry Cu problems

[prophoss]

So I did this thing... I got a the Alchitry Cu https://alchitry.com/boards/cu thinking that it would be a good dev board that I could learn on with better documentation than my cheap Chinese dev board. It can be used with open source tool chain as well.  The problem is that the I/O pins are no exactly what I had expected. It seems that the only way to add peripherals is to buy their IO board. So that is another $30 or so. Does anybody have any ides how to use the headers as they are? Is there a simpler option? 

[asmi]

They provide a schematic for the board, so open it up to see what's what.

[prophoss]

I looked at the pinout so I know what attaches to where. What I’m wondering is how do I attach a sensor to a pin? The bank has a different design I’ve not seen before.

[asmi]

The bank has a different design I’ve not seen before.

Not sure I understand the question. What do you mean "bank has a different design"?

[prophoss]

If you look at a picture of the board there are 4 banks of pins. These are the IO pins. The design is not the typical male to female pin. I was wonder how these work? How do you attach things to them?

[rstofer]

I think you have to come up with the matching connector.  I suspect it will be board-mount so you may need to build some kind of adapter if you want to wind up with standard headers.

You might read the home page and find:

By adding stackable expansion boards similar to shields or HATs called "Elements," the Alchitry Cu is able to expand its own hardware capabilities by adding prototyping spaces, buttons, LEDs, and more!

This is not what I would consider a 'friendly' board.

If you look at the pictures you will find the board is built by Sparkfun and if you search their site, you will find the matching connectors

https://www.sparkfun.com/search/results?term=alchitry

Pay attention to the board-to-board connector because all of the board mounted connectors are female and this requires a double male connector.

[asmi]

If you look at a picture of the board there are 4 banks of pins. These are the IO pins. The design is not the typical male to female pin. I was wonder how these work? How do you attach things to them?

They look like a standard high-speed connectors to me. Find out mating part number and make yourself a board if you want. They opted for high-speed connector in order to leave possibility of connecting something high-speed, but if all you want is a bunch of flying leads, you will need to either make or buy a breakout. This is still better than just using 0.1" headers because they preclude high-speed. I design most of my boards using similar connectors for the same reason - for low speed flying leads, additional connector is not a problem, but the reverse it not true.

[SiliconWizard]

If you wanted to easily connect stuff to a board for experimenting/quick prototyping, then it's definitely not the right board for you. Sorry, but should have looked obvious when you ordered it. Yes those are high-density connectors. While you can find matching connectors, those are fine-pitch SMD and I don't see how you could avoid making your own board (or buying a ready-made one).

[prophoss]

Ok, that sort of helps. What can I connect to this type of connector? For instance a screen? Maybe using a flat cable? This is very new to me. Could someone give me an example to go by?

[rstofer]

I think you have two choices:

Build a PCB with the matching connector(s) located at exactly the right spacing (and that may be difficult) or
Buy one of the Sparkfun boards that seems appropriate and go from there.

Personally, I would not recommend this board given the oddball connectors.  They may simplify high frequency signaling but they are a mess for prototyping most everything else.  Unless you can use the Sparkfun boards...

https://www.sparkfun.com/products/16524
https://www.sparkfun.com/products/16581

Note that the prototype board should stack directly and leave female socket exposed for further stacking

Tutorials
https://learn.sparkfun.com/tutorials/tags/fpga

[asmi]

Actually I think this board has greater long-term potential once you move past the stage of blinking LEDs and will want to explore connecting something more high-performance. But you will have to start making your own daughter boards with custom peripherals - that's when this board design will really begin to shine. That said, FPGA on that board is not very large, so maybe at that point you will have to move to a larger device.