The main 8 valves all work fine, but now trying with an expansion board and things are a bit funny.
1) If I start with the expansion board connected, the unit seems to thing it’s an AC unit rather than DC? None of the valves work then, presumably because the DC pre-charge/common side circuitry isn’t being operated. Could well be an hardware problem, but wondering whether this provides any clues on where to look… scratching my head a bit as it’s a relatively simple board and can’t see anything obviously wrong.
2) I’ve built the first version of the expansion board (using older I2C expansion board), and just want to check if there are any errata there. For instance, I noticed that RT1-8 on the main board are 1k, but RT1-16 are 220 ohm on the expansion board (I’ve tried with 1k as well just for good measure, but doesn’t seem to fix anything).