Flexible GPIO routing Arduino shield

Question

I want to make a combined MIDI In/Out/Thru + MDX Output shield, so I can order/design just one shield for all my needs.

It is intended to use the shield for Arduino Mega which has 4 UARTs, and I want to stack multiple of these on top of each other, and use jumpers to select which UART pins will be used for MIDI In/Out (1 UART = 1 MIDI In + MIDI Out).

For the DMX part, I could do the same, not thought about that yet, I probably need one DMX output, so I just use the DMX output of one shield and not use the others (maybe not even solder the components for it).

Also, maybe in the future I want to move to Arduino Due, which is 3.3V, and I might need an alternative routing for some components.

What is the best way to create this flexibility (especially for the UART pin selection)?

I was thinking about the following two solutions:

• Solder pin headers and use jumpers to make the correct connections; because the device will be transported a lot, I might glue the jumpers.
• Solder pin headers and I solder small wires as jumpers (like permanent wires).
• Use resistors to make the connections, 0 ohm like a jumper, and do not solder the other connections.
• Dip switches.

But maybe there are better solutions I didn't think about.

Answer 1

For robust connections like this I like to use normal pin headers, but instead of using push-on jumpers I make wire-wrap connections. A good wire-wrap connection is very reliable.

The disadvantage is that you need to have a wire-wrapping tool and the special wire used with it. As an old timer I happen to have that on hand anyway.