Simple question with switch


I was creating a remote control to my wireless remote car and I decided use a radio (remote control) that I was gonna integrate with my arduino to read the buttons state and potentiometer. My radio is this:

I started simple: in the right and left top of the radio there are 2 switches. Simple switches. I opened the radio and I took some photos to you see it. Attached.

You see there are 3 solder points from this switch, I think the manufacter solded 2 legs together, that’s why I dont have 4 legs.

So, I connected the GND from my arduino to one of the solder points and I connected my arduino PIN 2 (which is in INPUT_PULLUP mode) to another solder point. Then I read the state of the PIN 2.

Initially, when nothing is connected my arduino reads 1 (HIGH) of course, cause it’s INPUT_PULLUP. Now I connect the jumper from PIN 2 to one of the solder points and the GND jumper to other solder point. Then I read it in my arduino, it says 0. I am not pressing the switch, it reads 0 without pressing. So I moved to the third point (C) and read the state of it and it was also 0. I tried changing the sold points I was connecting my jumpers and it always reads 0 even if I am not pressing the button! I wanted to read 1 and when I press the button it should read 0, but it always reads 0 even if I not press the button, it does not matter any of the two points (A, B and C) I connect.

What is going on?



We don't know what else is in the circuit.... You've go a switch, but you don't have a switch alone... It would probably act like a switch if you unsolder it from the board.

The pictures show that points A and C are also connected to each other, probably GND (as it is a large surface). Point B is the only that is visibly isolated from the other points. As DVDdoug already said, the rest of the electronics of that remote are doing something, you can't just put some other signal to it and expect it to work. Measure voltage levels of these buttons while the remote is active and pressing the button and releasing it. Perhaps you can work out some solution after that.