LED "capacitance" won't get lower

[skimask]

I have not yet dealed with this kind of touch sensors but have an idea for flotulopex: Use all 7 segments, or at least some of them, to measure the ambient light instead of the dot only. I think you will get more reliable data.
When I have the time I'd love to experiment on this.
Ioannis

There ya go...you could use some of the lit segments along with the dot. At least you'd get a better average. And some of the light from other lit segment bouncing off your finger might help the other 'sensing segments' give you better numbers.

[flotulopex]

I did so already (using all segments).

There's no big difference with using the dot-point only.

I spent around 20 hours on making tests with different LED configurations and finally, I think the best way to handle "compensation" would be to influence the LED's capacitance.

But up to now, nobody could give me a hint on how to achieve this...

[skimask]

I did so already (using all segments). There's no big difference with using the dot-point only. I spent around 20 hours on making tests with different LED configurations and finally, I think the best way to handle "compensation" would be to influence the LED's capacitance. But up to now, nobody could give me a hint on how to achieve this...

If, in fact, it is achievable...which I don't think it is. Sure you can change the 'charge voltage', but it'll still discharge at the same rate. You can change load resistance, which will also affect your charge time.
Maybe you might need a different type of display, maybe a different color?
How about some sort of constant overhead light (front lighting?)...
You've got a neat idea...and I'm thinking...still...and it hurts

[Ioannis]

skimask's keyword is "rate". That won't change with voltage only.

Given the voltage and the load on the capacitance of the LED the rate will always be the same.

Only by changing the load presented to the LED will change the rate. And now it came to me an idea. Why not put a second pin of a PIC in parallel to increase the load when you want and then set it at tristate again? May be and a third one?

Ioannis