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Limit Switch Troubleshooting

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  • Chris_nunes
    A dysfunctional limit switch is a dangerous thing for these gliders.
    Let me guess, the buoyancy engine plunger gets to the switch and just keeps running and makes an uncomfortable noise while you scramble to hit the power switch? If that is true, (not the first time) then the button is not doing its job. That means it is not working mechanically and/or electrically.(assumption: Firmware = SeaGlideV1_0.ino or SeaGlideV0_9noIR.ino)

    Mechanically speaking, sometimes the button is not seated right in the Servo Mount, so when the plunger comes in contact, the button will jam sideways and not actually switch. To test this, I would run the buoyancy engine dissembled and manually click the button to stop the servo and change RGB color into coast.(no plunger). If the button does nothing, check electrical.

    Electrically, in order for the button to do its job, it has to complete a path from the Pin 11 on the Arduino Pro Mini to the negative side of the battery (gnd). Anywhere in that path could be the problem (don't be overwhelmed its a small path). I would try some steps:
    1. Test the conductivity of the switch with a multi meter if available. (the beep when the leads touch mode) This will verify the switch makes a connection when actuated. (not broken)
      1. If the switch is covered in hot glue try it at the 2 connections to the circuit board. i have seen these connections broken a bunch.
    2. Make sure the rainbow wires are soldered to the circuit board, and that the wires have not broken from handling (very common)
    3. Make sure the pins on the circuit board and pins on the Arduino are well soldered and mated to each other properly (feels far fetched since the servo works, but it is the end of the journey for the button signal)
    4. If that dose not work re flash the firmware and try again.
    5. Post what happened because that was all of my guesses
    Good Luck, and remember, debugging is the best part!

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  • Harrell27CI
    started a topic Limit Switch Troubleshooting

    Limit Switch Troubleshooting

    I have a group who is having trouble with their limit switch not working.
    We loaded the program onto the Arduino and went to test it. When the plunger reaches the limit switch, it doesn't register and allow the program to enter the coast phase.
    I thought that maybe the switch was bad so we removed it and the rainbow wires and reinstalled a new switch. Any idea of what else I can try?
    I am not an engineer and have very little experience with this.
    Any feedback would be greatly appreciated! Thanks!

    Last edited by Harrell27CI; 04-04-2019, 02:54 PM.