The tilt maze console
This device is a battery-operated, gravity driven implementation
of Andreas tilt puzzles. As it is tilted, mercury switches
detect the tilt and, on a matrix of 10x10 cells, LEDs appear
to "roll" from cell to cell exactly as they would do
under gravity and according to the rules of Andreas tilt
puzzles. The package measures approximately 17cm by 10cm by 4cm.
The LED matrix is overlaid with a grid printed on transparent
film, allowing walls to be positioned through which rolling LEDs
cannot pass. The layout of the grid is communicated via a user
keypad by typing a code number printed on the overlay. The unit
can be pre-programmed with details of up to 100 of these grids,
and a further 5 grids can be defined and saved using interactive
puzzle editors, also operated via the keypad.
In addition to the LEDs that represent rolling balls, one
or more additional flashing LEDs, representing "targets",
may be present. These targets do not move when the device is
tilted, they remain in the same place. If however a ball rolls
over a target, the target is extinguished. The grid may also
have one or more cells marked so as to indicate the presence
of a "hole". When an LED rolls over such a hole, it
disappears from play. An internal sounder provides audible feedback
by clicking as the LEDs roll from cell to cell, and bleeping
and chirping as targets are extinguished.
The usual objective is simply to extinguish all targets, but
puzzles with alternative objectives are equally possible, such
as extinguishing all "rollers" by dropping them through
For the technically curious...
Internally, the device is comprised of a 4MHz PIC microcontroller
which contains 8K words of flash PROM and 368 bytes of RAM. The
100 LEDs are organised as a multiplex of 4 columns of 25 rows.
The 4 columns are strobed in software by a 2mS clock, providing
a complete repaint every 8mS, equivalent to a 125Hz refresh so
there is no visible flicker. The four mercury switches and the
the 4x3 keypad combined to form a single 4x4 matrix, polled by
Battery life was obviously a major design consideration. Powered
by four alkaline AAs, it has been found that in practice typically
15-20 hours play is possible without any noticeable deterioration
in brightness, and up to 40 hours before the LEDs become excessively
dim. For simplicity of operation, and to avoid the use of potentially
unreliable cheap mechanical switches, switching On and Off is
performed via keypad sequences. When "off", the PIC
is actually placed in low-power sleep mode, drawing only a few
microamps, presenting a drain which is negligible compared to
the batteries shelf-life.
I experimented with the possibility of using the LED matrix
to provide scrolling text for user messages, with a custom character
generator tailored to the 10x10 display. This was not particularly
successful as it turned out to be a bit like trying to read a
newspaper through a microscope! From longer distances (10 to
30 feet), the scrolling text was highly legible despite the limited
display size. I have not developed this aspect any further other
than to add a novelty feature - you can turn the unit on either
side, or upside down, and a scrolling banner reading "Roll-Play,
from clickmazes.com..." automatically self-rights itself
and so always reads horizontally.
Further development, if I can ever find the time, may centre
around some kind of animated display on the LEDs, accompanied
by appropriate bleeps and jingles, to provide the "reward"
when a puzzle is solved.
console design &
implementation Bill Mitchell 2001