hi, I designed a simple 4 pole touch key using ttp223 IC. I encountered two problems when using it. sometimes when I touch a key, another random key switches. and sometimes when I reset power, a key switches to a condition and never switches back after touching. I attached the 1 pole circuit and the power circuit. about the component with the picture of LED I should say that its a PCB pad connected to the third pin of ttp223 and two back to back LEDs are placed under it and a light guide which distributes light is placed over the LEDs. and a 4 mm glass is placed over the light guides. in the power circuit, I used a 220 to 5v small SMPS. the relays are 5v dc and 120v ac.
what do you think the problem is?.
I found that there is something called snubber circuit which is a resistor series with a capacitor parallel with the contact pins of relay for suppressing excessive noise and also there is an option of optocoupler for isolation and suppressing noise. are these useful in my case?
thanks in advance