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Urgent help needed competition tomorrow

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  • Urgent help needed competition tomorrow

    I just can't solve this disconnection issue. It's always 1 of the 2 rev controllers and never the same one. When one does go missing from the bus its light goes solid green. I can't see anything in the manual about solid green. Please help as of right now we can't compete.

  • #2
    Once the app connects to the hub it should go green with blue flashes. Number of blue flashes equals the hub address.
    Green lasts for several seconds.

    Have you verified:

    1) That the two rev hubs have different addresses:
    2) Based on your app version, you may want to for the one attached to the phone to be a lower number (eg: master on phone = 2, slave = 3).



    • #3
      Hello Phil. We had our competition today and an army of first volunteers tried it all. Between our 2 teams and 10 rounds we had 2 battery disconnections from the friction lock rev connectors and 4 USB disconnections. This was with new cables and even brand new phones first let me try. They took log files to analyze and the even went through our code. It is not how you want months of work to end but at least the kids won all the rounds things worked correctly and they seemed like they had fun .


      • #4
        Hello Phil I know you are invovled with FIRST. I am a pretty good hardware designer during my day job. I believe implementing these will fix most problems.

        1) Place a SOM on the REV controller to take the place of the phone. By using a SOM you can upgrade the Android portion but just removing it and replacing it at a cheaper price than a phone. One I would recommend:

        2) All connectors should have a lock. The power connectors not locking is a huge oversight.

        3) Add this eeprom EEPROM to the robot controller

        This EEPROM is 30 cents and it will add NFC to the robot controller.

        4) Select a driver phone that has NFC. Through the NFC app pair the phone to the robot controller by writing all the phone parameters to the eeprom.

        5) Make the robot controller an always on wifi direct hotspot and once the FIRST app sync through NFC the WIFI direct pairing is done.

        6) All user interface functions and updates for both the robot controller and phone are done through the app.


        • #5

          The development of what you have recommended has been underway for several years.

          see. This was used by FIRST Global for the past two seasons.

          The current unit uses the snapdragon, but could not be deployed for FTC this year due to lack of availability of that board.

          Unfortunately FIRST it is between the two production sweet-spots.
          The required volume (5-8000 units per year) is too large for a development board like the 410, and too small for really large scale mass production (like a phone).

          They are working on alternatives, but this stuff takes time and resources.


          • #6
            I will agree that the Power connector choice seems flawed.

            Using a connector that is used in the high reliability are or RC planes and cars makes sense, but something got lost in the implementation.

            I have seen many REV modules that the power cord just falls out of. Replacing the cord makes no difference. The problem is on the Expansion Module.
            I feel that the pin spacing must be critical and the PCB just does not seem to be maintaining it ????

            On my systems I have resorted to squeezing the pins on the PCB receptacle together slightly (to increase the friction) and then we will hot glue them in place once we start competing.

            I am glad the power daisy chaining requirement has been removed.