How does capacitive sensing work? I don't mean how do I read the sensor... I know about touchRead(). I mean, how does it behave?
I've seen some examples which look for a value of 2000-3000 when someone touches a wire. Makes sense. But does the value drop over time if you continue to touch it, or does it remain relatively steady?
And what if I mounted the Teensy in a box, and then attached the wire to the box? I assume that it can sense the touch if it's metal. What about plastic?
Also, how would the sensor handle differentiating between the box and a touch? When I connect the Teensy to the box is the value gonna jump to X just from that, then up to X + 2-3K when a person touches it?
And if the box is sitting on a table wouldn't that be the same as a person touching it while standing on the ground? Do I have to insulate the box from the ground with rubber feet?
Which brings me back to the question of whether this touch interface can even work if my enclosure is plastic. Perhaps I need to stick a metal plate inside the enclosure to make it work like those PCBs with the touch pads they sell for capacitive sensing? I guess those are insulated, so you're not directly touching the metal.
My end goal here is to make a box that may be either metal or plastic that the user can touch to trigger one of several actions based on how long they touch it. And it has to work consistently, like one of those touch lamps. I can't tweak the values once the end user gets the device.
I've seen some examples which look for a value of 2000-3000 when someone touches a wire. Makes sense. But does the value drop over time if you continue to touch it, or does it remain relatively steady?
And what if I mounted the Teensy in a box, and then attached the wire to the box? I assume that it can sense the touch if it's metal. What about plastic?
Also, how would the sensor handle differentiating between the box and a touch? When I connect the Teensy to the box is the value gonna jump to X just from that, then up to X + 2-3K when a person touches it?
And if the box is sitting on a table wouldn't that be the same as a person touching it while standing on the ground? Do I have to insulate the box from the ground with rubber feet?
Which brings me back to the question of whether this touch interface can even work if my enclosure is plastic. Perhaps I need to stick a metal plate inside the enclosure to make it work like those PCBs with the touch pads they sell for capacitive sensing? I guess those are insulated, so you're not directly touching the metal.
My end goal here is to make a box that may be either metal or plastic that the user can touch to trigger one of several actions based on how long they touch it. And it has to work consistently, like one of those touch lamps. I can't tweak the values once the end user gets the device.