Hello, I use a very old Linux based box for test drivers, it provides multiple buffered DIO to convenient screw terminals on the case. I want to replace it with something modern, and looking at rPi. However, access to the (unbuffered) pin header on the CPU board looks untidy, none of the cases I’ve looked at clearly support it.
I can lash up some buffering, and at a pinch install the Pi in a larger case, but would be interested in any suggestions on what might be doable while still using the housings provided. An alternative might be a DIO board with USB interface if one exists – but there needs to be a convenient way of interfacing the USB to my (C++) software.
Any suggestions welcome.
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Hi Bruce.
I have a rig similar so I’m keen to help.
I’m struggling to imagine your exact rig, and so I can’t quite make sense of your requirements.
Could you shoot through a photo so I can orientate myself to the task? 
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Hi Johnny, Thanks for reverting. Here’s a photo of what I’m using now, it’s about 15 years old and becoming problematical OS-wise.
What I want doesn’t particularly have to be physically like it, and as I mentioned I can buy a plastic box, mount the rPi in it along with some breakout boards for buffering, and some terminals on the back. But there are advantages in using a rPi-specific enclosure in terms of the front panel USBs & al, with a ribbon cable from the 2-way pin header to a separate interface device. It’s just a pity that actually accessing the pin header with the board in any of its native boxes appears to be troublesome. I’ve read about people cutting slots in the top, but if you have a fan I guess that’s not feasible either. I wonder whether access to the header was poorly considered as part of the initial design, they obviously wanted the processor box to be as compact as possible. Or maybe I’m missing something in what the header is intended for.
This topic isn’t worth sweating on guys, I was just wondering if anyone had come up with a whiz bang arrangement. I have a couple of solutions in mind, just that they are a bit untidy.
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Bruce right from version 1 the Raspberry Pi was made for connecting things, so I’m surprised you see it as untidy.
I think you are really after one or more of the RasPi HATs. There are lots of existing add-on (Hardware Attached on Top) boards to make interfacing easier for different types of devices … but looking at Core’s Raspberry Pi option in their “Shop” menu I can see where you got that impression 
So much focus on all the different RasPi models, bundles and cases … and all the useful interesting add-ons tucked away at the end under “other Categories”.
Generally I would recommend the (40-pin Raspberry Pi GPIO Breakout | Buy in Australia | CE04441 | Core Electronics)] and a solderless breadboard, or https://core-electronics.com.au/prototyping-kit-for-raspberry-pi.html for starting to play with GPIO signals … but it sounds like you’re well past that stage 
Have a look at the Model B Plates and Hats section for connecting things like PWM servos, ADC, motor controllers, even AI. Pi Zero Hats also work but are physically smaller. Possibly you’re after more general board like Pi-EzConnect Terminal Block Breakout HAT | Buy in Australia | ADA2711 | Adafruit | Core Electronics or Expander Pi | Buy in Australia | CE07491 | Core Electronics.
This reminds me of the GertBoard which I bought with my first Raspberry Pi model 1B (but never used). If you would like it I am happy to post within Australia.
As for enclosures, I agree. It seems most HAT manufacturers have decided that theirs should be the only add-on anyone will need, and so they do not use stackable headers. Similarly the majority of cases don’t allow for add-on boards, or are designed for only their particular HAT. There are however some which are more flexible.
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Thanks for the very informative response Don. Yes, I did miss the HAT page. I’ll check out your suggestions, highly likely that one of them will fit the bill.
And thanks for the offer of the board, but I’m targetting a midrange Pi5. I have too many old boards languishing in drawers already :-/.
Regards
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