Well,

I see we all have been reading and viewing the same documents and medias already.

I've tried this with lots of different LEDs (IR, simple colored red/ambre/green/yellow/blue/white, 7seg and even a bicolor one) and they ALL work. Of course, I get different results but it works always.

Since the way to "measure" the LED with a PIC is to calculate it's discharging time (state change), to make it work fast, I want to REDUCE the "RC time".

So, if now I'm counting around 4000 counts (see post #1) until the LED goes from state "1" to state "0", I want to speed-up things with lowering this value and make it become something around 100.

How can I reach this?

Depending on the surrounding luminosity, the scanning/counting process can vary from a few milliseconds to seconds.

As mentionned in lots of articles, the surrounding luminosity affects tremendously the discharge time of the LED and compensation is mandatory.

In my mind, the only way to compensate the longer discharging time due to surrounding darkness is to reduce the voltage applied to the LEDs.

Is there another way?