New to the website. I am having some wiring issues with my OpenROV 2.6. I have observed a constellation of symptoms that hopefully makes the issue specific. Would greatly appreciate any help on this, it is my first solo electronics project.
I check the voltages on the 25-pin connector, all perfect (12 V for both power supplies, 5 V on the tether). These are always perfect.
My ESCs receive voltage (12V) on their 2 electrodes, I can tell by testing the backside of the board. However, they display a constant red LED and do not respond to holding down the "set" button.
I get good voltages at several points on the controller board (D11, J12, J17) but get no voltage for the checkpoints at the center of the controller board (where the comm board connects).
In J6, where the BBB connects, I get 0.8V between pins 1 and 3, and nothing else.
I can power on the BBB and view the webcam when I plug the topside adapter's powercord into the BBB (powering it directly) so I don't think it is a BBB issue.
While none of the 25-pins seem to short when I test with multimeter, I do see that the motor A/B/C pins all seem to be connected (shorted?). Is this normal? It seems like they all touch each other within the bell of the motor and it would be very hard to prevent that with the shrink tubing.
Lastly, I noticed that sometimes when I power up, or toggle an ESC on/off switch, or accidentally touch two parts of the board with a multimeter probe, the ESC lights shut off and 25-pin voltage, when measured from the pin nubs on the back of the controllerboard, sinks from 12V to 2V. If I unplug the 25-pin and test it directly, it is 12 V, but plugging it in causes a sink to 2V. The 2V measurement on the back of the board persists even while the 25-pin plug is unplugged (capacitors discharging slowly)? Usually if I wait awhile, I can re-plug the 25-pin and go back to normal 12V and solid red ESC lights. Maybe an intermittent short?
So to recap the observable symptoms:
1) Solid red ESCs unresponsive to set button
2) Normal voltages around perimeter of board
3) But no voltage for Comm board pins
4) And only 0.8V for BBB pins (between 1 and 3)
5) Motor A/B/Cs seem to be shorted within the motors
I have seen prior posts indicating this can be a polarity issue, I have tried switching the polarity to no avail and have measured many times.
I have also seen that connecting J17 to J18 can force power to the BBB. I do not have a J18 on this board.
Thanks very much for any help!