Made a couple versions of my MCP board. One holds 2 MCP23017, the other holds 4. While both are pretty space efficient, I am leaning towards the 2 chip version, since it will go together quicker, and I can test it sooner.
The 4 chip version will make it so I only need 2 of them, but the extra wiring involved make it more complicated. 2 chip version will be easier to wire up, test and might make it easier to find where to put the circuit boards on the chess board.
Draft 2: 2 MCP23017's
Draft 3: 4 MCP23017's
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