Comments on: Touch Sensing Building Blocks I

By: c.moore

c.moore — Tue, 14 Aug 2007 07:22:53 +0000

Sir, would it be ok if I replicated a summary of this process on my forums?

http://nuigroup.com/forums/

By: tmpvar

tmpvar — Sun, 31 Dec 2006 00:40:47 +0000

Excellent, excellent, and cool… I just tried the laser -> red led, and I had no idea. THE POWER OF THE LED :-P

By: justDIY

justDIY — Tue, 08 Aug 2006 11:54:52 +0000

to use the leds as binary sensors/switches, there are two ways … the first involves still using the ADC, along with accumulators in software … the second is to use the schmitt trigger inputs on the uC … the ST inputs are sensitive enough (high enough impedance?) to register the tiny tiny current an LED produces via the photovoltaic effect … so an LED thats being lit registers as a logic high, a dark led = low.

this makes it super easy, problem is, most pics have very few ST inputs, some models don’t have any…

By: Cobalto Iridium

Cobalto Iridium — Tue, 08 Aug 2006 00:52:27 +0000

…. by the way… in order to avoid the lighting issues… What about modulating the ‘lighting’ LEDs?, So, you can declare a valid ’1′ or ’0′ only when a pulse train has been detected by the ‘sensing’ leds, it will take more than 1ms to detect a valid state regardless the light conditions but it could be worthwhile the exercise….

Just my 2cents…

Cobalto…

By: Cobalto Iridium

Cobalto Iridium — Mon, 07 Aug 2006 21:26:29 +0000

…. I’ve followed this LED sensing stuff for quite a while and I just wonder if it is possible to handle the sensing LEDs just as a binary switches thus avoiding the need for an ADC logic [ of course, some pre-conditioning will be needed ].

In my line of thought, I’ll try to add this LED sensing [ on/off ] into some audio gear that I do in order to digitally select the audio source, volume [ just up/down kind of control ] with an array of 4 LEDs per indicator/switch covered by a glass… in any case WOW..!!! it is remarkable what you have done…!!!

Greetings from Mexico….!