Activate Induction Hob by Arduino

Discussion in 'General Electronics Chat' started by Pivato, Apr 14, 2016.

  1. Pivato

    Thread Starter New Member

    Apr 14, 2016

    This is my first question in this forum, I hope you guys can help me figure out a solution to my problem. I´ve spent a few days trying to solve this and could not find a stable solution.

    What I am trying to accomplish is a Induction Hob controlled by Arduino. I've already did that with a portable Induction Hob and a Bechoff PLC: I soldered a 100 nFarad capacitor to the capacitive buttons and connected it to a relay that shorts it to the Ground, simulating the finger pressing in the button. It works pretty well, and I could do some automatic programs for my hob, It will turn on the hob, select the function and control the power (by "pressing" the + and - power button according to the feedback from a temperature sensor) and turn off at the end.
    Now I am trying to do the same with a more powerful Induction Cooker. I am using an EGO interface and Power Module. This is the control interface of my Induction Cooker, which controls the Power Module:

    So, what I want to do is basically the same: Connect each button to a relay which will be controlled by an Arduino, simulating the finger pressing. Below each those black pads there is a layer covered by solder, which I believe will sense the change in the capacitance caused by the finger pressing.

    I tried several different approaches: Connect a capacitor to the layer and then short it to the Ground (Basically what I did in the other project) and it didn't work. Short the capacitor to VCC, no success. Short directly to GND or VCC, and it doesn't work.
    I tried also to add some resistors and it didn't work as well.

    It seems that the black pads have a resistance of about 1 MOhm. I tried to glue a wire to it and short it to GND or VCC, and it doesn't work, but if I touch the wire with my finger it will work.

    What could be done to simulate the finger pressing with a relay?
    Sometimes it worked, but it was not stable: If the wire was bended the other way it would not work anymore.

    Thank you very much for taking your time to help me with my project!