Valve position reporting

[mdbartos]

For the sake of record-keeping, valve should report -1 * (received position) instead of just -1 when acknowledging a command.

[bpwong-um]

That can be done here

perfect-cell/perfect-cell.cydsn/valve.c

Line 189 in d1ec711

readings[*array_ix] = -1;

We'll have to include a special case for when the desired position is 0

[mdbartos]

Actually, on second thought we should probably just report the moved-to position as a separate measurement. achieved_position or something like that.

[bpwong-um]

The latest firmware transmits the current valve position, which let's us continuously track the position whether it was remotely-triggered or moved manually