100 Nicolas Collins
Chapter 26: LCD Art
You will need:
- A toy with an LCD screen.
- Some test leads.
- 9 volt battery and battery hook-up clip.
- Hookup wire.
- A basic oscillator circuit from Chapter 18 or 20.
- Hand tools, soldering iron and electrical tape.
A lot of handheld toys and games incorporate small LCD screens. Find the
contact points between the circuit board and the screen and try listening to them
-- sometime they produce very nice, rich chords. But here are a couple of purely
visual hacks, natural bi-products of your toy experiments.
In many cases the LCD only contributes “foreground action” to the game; often a
simple printed cardboard sheet provides the backdrop. If you feel creative with
a pen and paper you can often transform the game with an alternative
background of your own wicked imagination -- what would Mr. Potato-Head’s
nose look like on a......
Moreover, when the screen is removed from the circuit its visual elements can
sometimes be turned on and off with simple connections of voltages, either
directly from a battery or from an oscillator. Start by tinning the tips of the red
and black power lines from a 9 volt battery clip, so they have a stiff, sharp points
-- you can also solder sewing pins to the wires for stronger, sharper contacts.
Locate the connections to the LCD -- usually these are tiny points embedded in a
rubber-like strip at either end of the glass. Press the + lead against one
connection and the ground wire to another. Keep trying different pairs of points
while watching the screen -- at some point an LCD element should become
visible. Make a note of the location of the contacts and keep exploring. If you
find a set of images that you like you can find a way to make the connections
permanent -- usually by wedging and taping wires or pins against the contact
strips.
You can animate the images by using the outputs of oscillators, instead of battery
leads, to drive the LCD elements. Take one lead from the ground of an
oscillator’s circuit running at a low speed (tick-tock range) and one from the
oscillators output. Find good connections as you did above, but now you can
adjust the oscillator speed to cause the LCD elements to turn on and off, creating
your own animation.
The small LCD screens bear a certain resemblance to old Daguerreotypes, and
have a certain charm as modern miniatures. The screens can be combined with
new backdrops (as above) or left in their rather ghostly, mostly transparent state
as tiny digital stained glass windows.