I have a very basic circuit with an homemade FSR (made from IC insulating foam) and a LED.
The LED is supposed to emit light with an intensity controlled by the pressure applied on the FSR. The circuit behaves as expected except that the LED is also lit when no pressure is applied but an object is close to the circuit. So there is obviously some EMI/RFI problem here. The data from the sensor also shows there is some cyclic noise in the data.
You can see the circuit below. There is a video to show the problem here:
So what should I do to solve this ? I have some Linqstat film. Should I wrap the circuit with it ? Put the circuit in a metallic box ?
Would it help if I’d connect the metallic plate which is under the breadboard to the Arduino’s ground ? Or is it automatically connected yet ?
Should I use an opto-electric isolation between the Arduino’s 5V pin and the circuit ?
Any help would be highly appreciated.