The 8 sequence LEDs represent 8 time slots that
can hold sounds. When one of the LEDs is lit, if a
sound is triggered using one of the shapes, it will
be repeated each time that LED lights up.
Each of the 4 shapes represents a different
sound. When you press a shape, the sequencer
will remember what slot number ( 1– 8) you were
up to and which sound was triggered, and it will
play that shape’s sound each time that slot is
cycled through. This lets you build up a sequence
of sounds one at a time, up to a maximum of
8 in the sequence.
You can change the sequenced sounds by
pressing a different shape during any time slot,
overwriting the previous choice. Individual sounds
can be cleared from the sequence by pressing
the same shape during that slot, a bit like a toggle
switch. Or you can clear the entire sequence from
memory and start from scratch by turning the
R-Tronic off and on again.
This project is just asking to be hacked. The
programming for the Picaxe microcontroller is in
BASIC, so you can easily edit the file R-Tronic
8-Bit.bas to change the sound effects for each
shape. You could also associate additional sounds
for when more than one shape is pressed at the
same place in the sequence. And the wooden
case simply holds the electronics, so you can be
as creative with it as you want.
Photograph by Sam Murphy
The shape pegs on my R-Tronic are interchangeable and fit into each other’s slots. The sticker is
just a guide, and it’s actually the position rather
than the shape that determines the sound. For
kids older than 1 or 2, it would be great to make a
version of the R-Tronic that only triggers a sound
when the shape matches the sticker underneath.
Keyed peg holes with matching peg shapes are an
obvious way to do this.
Watch a short video of the R-Tronic in action at