Capacitive touch - trapping a long press?

[HankMcSpank]

You might be able to use some code for a long press in a regular pushbutton and convert it to what you need. Robert

Hi Robert, unfortunately, I don't think that would be possible.

With a regular button/switch press using interrupts, firstly an interrupt happens (ie when the switch is pressed), then in the interrupt routine the rogram just rechecks after a short while to see if the same condition is held.

But with capacitive touch, you have to exit the interrupt routine in order to get the next 'timebase' (the timebase here being 'time' between a timer based based interrupt - & is used to count the output from the CPS module), in other words you can't hang around in the interrupt routine to see if the condition has held.

[cncmachineguy]

HI Hank. Here I go with my counters again. Once you detect a "press", the pressed condition becomes the "normal" Then you are really checking for "unpress". Check the time between the 2, and determine if it was a long press short press or whatever. So the counter is used to count the time while waiting for the release.

[rsocor01]

I was thinking of some logic outside the interrrupt routine, in the main program. In the interrupt routine you find the variables Last_High_Reading and Current_Reading. Even though the main program is stuck in a loop, it will still be going to the interrupt routine. I was thinking of something like this,

Cnt = 0
REPEAT 'Main program will be in this loop until sensor is released.
Cnt = Cnt + 1
Pause 2
If Cnt > 500 then RETURN 'A long press was detected. Exit sub-routine.
UNTIL Current_Reading > 0.8*Last_High_Reading

[HankMcSpank]

Thanks guys....I'll give both of those ideas some serious consideration as I hadn't considered either.