@OP
More interesting info. That indicates that the central point in the Y connection is available. That cancels the need for a djungle of equations. Apply +voltage to the centre, some resistors and use 3 analog input to read....
@OP
More interesting info. That indicates that the central point in the Y connection is available. That cancels the need for a djungle of equations. Apply +voltage to the centre, some resistors and use 3 analog input to read....