Fix the circuit

The device is connecting automatically to the app when using a metronome in the app and vibrating even when charging. I made a mistake of charging it from USB port on my electric piano. Almost fried my piano because the device is discharging a lot of current through the charging pins. Please make sure to disable it while its charging, this may lead to a housfire, I'm almost certain it will pop the breakers if connected to a wall socket.

Hi Kamil, thanks for your report - it sounds scary. However, I can't quite make sense of it. If the Core (or Pulse) is vibrating it draws power from its battery. The battery is charged via the charging cable which is plugged into your USB port. Why / how would the device discharge current back to the piano? Are you sure such a mechanism is possible? Are you knowledgable in electrical engineering such that I should investigate this further with the electrical engineer of our PCB designer? Thank you. Since this is more of a bug report / technical issue, rather than a suggestion, I am archiving the ticket. Of course we will fix any issues without anyone voting on it.

Changed the status to "Archived"

You should look into that, because it would be fair to warn people not to charge it at piano. What is happening is likely very simple to explain. When device is charging current flows normally, but when it is vibrating, the controller sends PWM signals to the motor to spin, those are short bursts that cause it to spin, which then causes the motor to generate current (every motor is a generator and vibration happen in the inertia phase). Unless you designed it like a mobile phone with a separate rail and well thought out current smoothing this extra juice produced by the motor will land on the feeding rail causing all kinds of hickups at the piano that is probably happy to supply the USB standard voltage and not so thrilled about those spikes :) Unsolicited engineering advice in case I'm right: disable vibration while charging via a firmware tweak.

Thanks for the detailed explanation, I will review this with our engineers!

No problem, for all we know maybe I have a defective unit with some short. Good luck 🤞