What I had in mind is really quite different. Perhaps we should start a public discussion?
As I’ve said in the STM32 Dev thread, there is no intention of using the nucleo boards beyond development and I’m looking for something more flexible that I can attach any CT to any ADC channel. There fore the morpho connectors are somewhat wasted when jump wires can be moved around.
We are also not planning on using the voltage dividers for the midrail, instead we want an op amp derived midrail. Although I might be tempted to still include the footprint and holes for the voltage dividers in case the opamp thing doesn’t pan out or even to facilitate a side by side comparison.
The shield is really quite dated now and it doesn’t have any protection for the ADC inputs so we would need to include clamping diodes and 1k protection resisters too on each input.
Also we had determined that the AC voltage divider needs to be a much lower impedance so we can sample the VT much much faster allowing us to have more genuine V samples rather than calculating/interpolating V values from a more sparsely sampled voltage.
To have ample CT sockets is far more important than the size or shape, 8 CT’s just isn’t enough, we are currently debating if 15 or 18 or whether we should provide more for room for expansion over that.
On the production units we do not intend having all the ADC channels on every device, but perhaps a basic 6ish channel device and then some slave IO board that stack on top and use the same processor.
It’s still very early days, hence wanting a flexible proto board type thing rather than a fixed design.
[edit - there is also an error built into the shield that we wouldn’t want to carry forward. The 3.5mm sockets ground the midrail when there is no CT plugged in, the intended behavior should be to short the adc input to the midrail, ie “zero” the CT signal. This is obviously mandatory to remedy if a common opamp midrail is to be used.