sprite_tm

37 Articles

Minimalist LED Light Detecting Candle

November 5, 2008 by 17 Comments

[youtube=http://www.youtube.com/watch?v=sPe5RtUOOdc]

Our flickering LED circuit combined two known circuit, and certainly wasn’t graceful because of it. [sprite_tm] saw quite a few areas where the circuit could be reduced. He ended up taking it down to just two LEDs, a battery, and an ATtiny13. The first step was getting rid of the current limiting resistors. The datasheet shows that with a 3V supply the AVR will limit the current well below the maximum current. The light sensor was removed next. [sprite_tm] referenced an earlier post on sensing with LEDs. He measures the voltage across one of the LEDs while it is off to see how much light is hitting it. The current draw while on is 10mA and 50uA while off.

Optical Mouse Based Scanner

January 7, 2006 by 41 Comments

Ever wonder what your desk surface looks like up close? No. No one has. Not even [Sprite_tm], but upon disassembling his optical mouse and discovering its 18×18 CCD he decided to put it to use (well, a different use). The optical chip outputs serial information to the USB chip in the mouse. [Sprite_tm] wired the optical chip to a parallel port and wrote a simple program to interpret the data. Not really useful, but it does generate some interesting pictures. Program provided, natch.