MADEONEARTH
Form and Functions
David Jones really liked his old Casio CFX-400
scientific calculator watch. As a professional
electronics design engineer, he appreciated the
greater functionality it had over other calculator
watches, which typically support only the four basic
functions. He was saddened when his 20-year-old
Casio finally bit the dust, so when he looked around
and realized there was no one making scientific
calculator watches anymore, he decided to make
his own.
He calls it the μ Watch (“Micro Watch”). His goals
were to make a scientific calculator watch that was
good-looking and practical, and could be assembled
from off-the-shelf parts.
“I could have designed a custom case for it, and
used custom parts to get the size down and make
it look like a store-bought watch, but there was no
fun in that! Using off-the-shelf parts was a real challenge and in the end was the most satisfying aspect
of the project,” Jones recalls.
A resident of Sydney, Jones has been publishing
projects in Australian electronics magazines since
he was 15. Besides his μ Watch, he’s designed and
built his own solar air heater called the Solar Sponge,
and written an interactive exercise program that runs
on iPods and other MP3 players. He also likes to get
involved with serious home renovation projects.
Jones has released his μ Watch source code under
the GPL to encourage third-party development, and
he sells kits for those interested in building one. He
includes a complete schematic and detailed photos
on his website.
And the μ Watch isn’t limited to being just a scientific calculator. Its programming port, universal
I/O port, and optional infrared remote interface let
you connect it to almost anything. “With the two-line LCD, full keypad, and 16-bit microprocessor, it’s
really a powerful general-purpose computing and
control platform,” Jones points out.
If you want a μ Watch that controls your TV, plays
games, or commands other user-designed devices,
just add some software. —Bruce Stewart
>> Build Your Own: calcwatch.com
Photograph by David L. Jones
20 Make: Volume 15
