Most of my tests have been done on the breadboard or free air connections between boards. This works with a few components on the desk but when it gets to the point that one wants to test any kind of integration between components it becomes difficult to keep an overview and more importantly making sure one does not create shorts or bad connections. I use lab power supplies, which ultimately is not a problem for shorts because the lab supplies handle that nicely by limiting the current or cutting the voltage. Nevertheless a more solid setup was needed.
I had a clear perspex sheet laying around and I mounted all the components I need for testing on this sheet with connectors accessible. I can hook up additional sensors, have all voltages created on board and only need one 12V power connection.
By now I have connected all the boards to power and just waiting on a few more plugs and short Cat5 cables. I have my own cable and modular connectors, but I cannot be bothered to make 8 short Ethernet cables when I can but one for a single $. Crimping modular connectors is a pain, making sure all cables are inserted properly is quite daunting and this times 16 is not a nice prospect.
I have tested each of the signal types I need to support and can now start with the integration test of the components.
I am still waiting on the CAN bus shields for the Arduinos though, but I expect them any day.