Automated Testing of P2's

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  • evanh wrote: »
    samuell wrote: »
    It was the wire that was making poor contact. The swap to the Analog Discovery forced me to swap the wire going to P62.
    The white wire could be broken inside the heat-shrink. Good time to resolve what is wrong with the wire so doesn't cause future issues.

    Wires can also be broken inside their own insulation, particularly with teflon or other high temp insulation. What happens during soldering the wire is that the solder wicks a millimeter or two up the copper strands under the insulation creating a solid copper/solder wire that any vibration can eventually break at the point where the solder ends. The resulting break can be a clean break that is relatively easy to find or an elusive one that that looks just fine whenever a probe is applied to the joint.
    In science there is no authority. There is only experiment.
    Life is unpredictable. Eat dessert first.
  • samuell wrote: »
    Update:

    Used an hefty USB charger module (my own creation), with a capacity of 2A per port, to supply power to the board. The current now goes entirely through the "P2 USB" port. The fact that the Vbus voltage is dropped seems to allow a condition where the "PC USB" port power switch (U502) is not off, fully on in part. Vbus now reads 4.89V and is within spec.

    However, the test still fails, as expected. I don't think that Vbus is a factor, but managed to exclude that, anyway. Maybe the clock generator is not strong enough to drive the pin through a 1K resistor?

    Kind regards, Samuel Lourenço

    Check the voltage out of that USB charger. I have found that many supposedly correct chargers still give me the lightning bolt up in the corner of my raspberry pi, indicating to low of voltage. Or perhaps add a really fat capacitor across the output.
    Particularly patient proactive practice positively predicates practically precise poly-processor Parallax Propeller programming paradigms.

    .
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