First off, I wanted something to keep the equipment dry and at the same time be able to run the power cables as necessary. At first, I thought about using a cheap toolbox and cutting out holes for the power ports and switches. One other thing that I was going to have to do was to figure out some sort of seal around the lid and some way to waterproof the connections going into the toolbox. However, after thinking about it, I decided that this was too much work on my part for what I was getting. I wanted something that I could buy and quickly setup as necessary since I was going to need a couple of these. So I settled on the idea of a DriBox which is a plastic box that has openings for power cables so that you can put say a power strip in it and plug cables into it. The cables are put into slots in the box that have grommets that fit around the power cables when the lid is put back on. It is not completely waterproof, but you can run a hose on it and it does keep the contents dry.
Next, I figured that I could take the electronics and put them on a piece of Plexiglas with standoffs that could be screwed into the Plexiglas along with some "feet" on the other side. That way, I could put everything together, check it out and then put it into the box quickly. That would save a lot of time for repairs. I could also re-purpose the electronics to another project later by simply removing the Plexiglas board from the DriBox and unscrewing the power lines. I also chose to put the 16 port io extenders on a full size Adafruit perma-proto board with connectors pointing up so that this could be reused as well. Prototyping of the whole circuit can be done on a regular breadboard and then moved over to the perma-proto board because the connections are identical. There is even space on the board for the connector to the Raspberry Pi.
The next post will have a circuit diagram for the 16 port extension. I might even invest in a RPi hat that has the same characteristics if I can find one.
