The PiRyte Multi-S is our first offering of a model railroad interface board for the Raspberry Pi.
This do everyting board allows the Rasberry Pi to sense active low conditions from such inputs as switch closures and occupancy detectors. Additionally, The PiRtye Multi-S controls Tortoise type stall motors from as well as relays, LEDs, etc...
Each PiRyte Multi-S can control up to eight Tortoise style switch motors, eight open collector outputs, and reads 16 active low inputs. Up to eight PiRyte Multi-S interface boards can be stacked together with one Raspberry Pi to provide tons of I/O capability.
Why Create this I/O Extender Board?
I created this board because I wanted a great way to control various parts of my model railroad, such as switch machines and signal lights with a Raspberry Pi. I also wanted something robust, extendable and easy to work with without necessarily getting lost in a pile of wires. After doing a lot of research, I just wasn't finding anything that match these criteria.
What is Special about the PiRyte Multi-S?
There are several things that makes this board special. First off, it is stack able and easy to mount to a solid framework. It seems a lot of the I/O extender boards I found just kind of flop around in space, which is okay if you're not serious about having something function consistently long term.
Also, I decided to use RJ45 and RJ50 style connectors. This provides quick connect/disconnect capabilities in case you ever need to reconfigure your hardware or troubleshoot something. I did not want to spend time and create confusion by needing to screw/unscrew dozens of wires just to swap out boards. Instead I rely on Cat5 and 10p10c cabling to run my signals to breakout boards, thus taking a more distributed approach to wiring. I also feel that cables are more secure and less prone to damage than individual wires.
Finally, I added an additional stacking header to route power from board to board therefore eliminating the need to daisy chain power wires from one board to another. The stacking header will route all the voltages commonly found on ATX style power supplies: 3.3VDC, 5VDC, 12VDC, -12VDC, and Ground.