Checkout Procedure
Lower Half Elex (LHE) Board, Coastal Profiling Float

2021-06-11	ECM	(from 2019 notes)

1.  Batt5V, Joint4V7

set JP2/3 	ForceOff
set JP4, JP5	Open (LEDs off)
Connect 0-36V supply to Batt P1 input

Ramp supply to 6V
Verify Batt5V = 5.0V and Joint4V7  ~4.7V, I(in) ~60uA

Set JP2/3	ForceOn
Ramp supply to 28V
Verify I(in) ~160uA
Ramp to 40V briefly (a few seconds, TVS will get hot), check I(in) < 200uA below 36V