Monday, 27 February 2012

Light Canvas - LEDs 4: Progress!

Having important things to do can be really motivating - for other projects. I've household repairs to organise, but can't figure out an elegant way for it to be done - so I'm ignoring that for the moment, and have made some progress on the Light Canvas :-)

Subsequent to my last post on this project, I satisfied myself that the circuit was ok, and ordered a bunch of components, and took the opportunity of a OxHack session to  breadboard the control circuit, which I did - except for the minor point that the circuit didn't actually work... Oh well, it was a nice event, and good to meet some more hackers and see what they were up to - I need to get along to more of that sort of thing!

Many months later, I've a working breadboard with the 555 astable circuit producing a pulse width modulation varied from 0-100% depending on a potentiometer. The 555 PWM doesn't have enough power to drive the LEDs directly, so it's used to control a transistor which effectively amplifies the power of the PWM enough for the LEDs. W00t!

This happened by:
  1. Getting the 555 PWM working on a single LED directly,
  2. then on a panel of 5 (on a breadboard) via the transistor, then (the next day),
  3. making up 9 perfboard versions of the LED panel, powered via the LED.

Video evidence:

Next steps;
  1. Convert the 555 circuit from breadboard to perfboard.
  2. Modify the frame to house the circuit, controls, and wiring.
  3. Modify the frame so the back can be attached, and hung on the wall.
  4. Stretch the canvas onto the frame.
  5. Install the electronics in the frame, and put it all together.
  6. Put on wall and bask in its glow :-)