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Serial debug
Start with U4, the serial output buffer. This is connected to the 3 pin connector, that then connects to the DB9 connector, and on to your laptop.
Not sure how one formats text to line up in columns in this forum ...
IC U4 - serial in then serial out then connector
11 tx tx 14 tx 1 OK
12 rx rx 13 rx 2 or middle OK
gnd 12 gnd 3 OK
The signals are OK, now for power and ground
Vcc 16 = 5v, 15 = gnd - voltage between is ... -0.233V? This is wrong. First thing that is wrong ...
Check that we have 5V being generated.
Start at the regulator, LM7805 pin 1 is 12V from battery, pin 2 is gnd, pin 3 is 5V
OK - 10.97 for Vbat, 0V = gnd, 4.97V out
Turn the power off to the control board (the power board was already off)
Continuity for 5V, U1 LM7805 pin 3 = 5V to
U3 Atmega pin 7,20 OK
U4 HIN202 pin 16 OK
Continuity for ground U1 LM7805 pin 2 = 0V to
U3 Atmega 8, 22 OK
U4 HIN202 pin 15 Nope. This is a problem.
Resolder pin 15. Pin 16 actually does not have a nice solder cup either .. and the tip on my soldering iron is wide enough that when I touch 15 I also touch 16 .. so I resoldered both pins.
And there is success! I can now see the Cougar 1.11B message and the config command works. Troubleshooting the rest of it should be a bit easier now!
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