• Hi,

    I'm working a small project just for fun. I'd like to open an electronic lock through BLE using MDBT42Q.
    The unlocking action is triggered by closing circuit between ground and another wire.
    I have though I would be able to connect these two wires to some PINs in MDBT42Q brakeout and open circuit between them programatically.

    However it doesn't seem to work like this.

    Can anyway give me a hint of what is the best way to interact with such circuit from MDBT42Q?

    Thank you,
    Marek Kowalski

  • Sat 2020.05.02

    Well Hello Marek @user112057 and welcome to the Espruino community. Thank you for your interest.

    It is likely (hardware) a pull-up/pull-down issue, not enough drive current, both circuits lacking a common ground or (software) the pin mode is incorrect. There isn't enough detail provided for me to make suggestions, but uploading the schematic, lock datasheet, link to tutorial if any and the current attempted code would provide some insight as there are too many combinations to just guess.

    Might get some ideas here:



  • Thank you Robin for your response. Let me elaborate.

    I have a 3rd party circuit (an intercom). I can take a wire and short two connectors on this circuit and this triggers the unlocking action. I would like to trigger the same behavior using MDBT42Q. I was hoping I would solder two wires to two GPIO pins on the breakout board of MDBT42Q and connect them to these connectors on the intercom circuit. Than I was hoping I would issue a command and MDBT42Q would open circuit between these PINs therefore shorting the connectors and opening the lock.

    Am I explaining this right?


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