Jump to content

LEDs as input devices


RoyalScam
 Share

Recommended Posts

OK Boxers! I won't even pretend that I understand micro controllers at this point, but I'm pretty sure that this may be the next big thing since the lighted push button switch.  I somehow stumbled onto this doc and thought that someone here with better chops than I might find this as fascinating as I did.  I didn't know that an LED in it's reversed biased state can actually be used as a photodiode, according to this doc a device can be made using the LED as both an indicator and input device.

I believe that this is being used in this video;

http://video.google.com/videoplay?docid=-6431755676396318073

And the paper describing the circuit is here;

http://www.merl.com/reports/docs/TR2003-35.pdf

Whaddya think, Sirs?

RoyalScam

Link to comment
Share on other sites

Well, poop.  I should've known it's been seen before.  Nice dream though.  Besides, Forrest Mims was cited in the article and it reminded me of all the great things I learned because of him, back when I was a geeky kid with a Library card.

Scam

Link to comment
Share on other sites

Search the forum, there already is a thread about this. As far as I can remember, the problem was using it in a matrix and scan all the LEDs in a reasonable time.

that's correct... mind you, it wasn't done in ASM, but in BASIC... so, if someone were to do it properly, and/or perhaps use a certain fancy new 32 micro powered dev board, maybe they would have more luck.... Hypothetically if I were to know someone in that situation I would tell them good luck from you ;) Wink, nudge, etc.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...