LENSFor this project, I picked up a few cigar
boxes at a local tobacco shop, but then I
stumbled across a stunner of a cigar box at
one of my favourite thrift shops. It was
clearly a few decades old, worn enough to
have a lot of character, and it had a hinged
lid, which is rare in wooden cigar boxes. I
paid $2.50 for it.
The other aesthetic
I was dead-set on with
this project was lighting
it with pink LEDs. Several
years ago, I saw a video
of a drone synthesizer
somewhere online. Its
case was made of acrylic,
and it was lit internally by pink LEDs. I had
never seen pink LEDs before, and I marked
them down in my brain as something
to use in a project someday. I found a
hundred of them for $6 on Amazon and
placed an order.
I rounded out my supplies for the project
with a sheet of acrylic, some potentiometers
and knobs, a tiny mono amplifier that runs
on 6–12 volts, and assorted bits from my
collection of junk, including a small speaker
and a limit switch.
THE GUTS
The first thing I needed to do was assemble
the guts of the synth. I didn’t want to
sacrifice an entire Arduino Nano to the
project, so I opted to use a knock-off Nano,
which resulted in some complications down
the line. One of the things that drive the price
of an Arduino is the use of an FTDI chip forUSB-to-serial communications. The knock-off
Nanos cost less, in part because they use a
cheaper alternative, the CH340 chip. The
CH340 chip behaves in basically the same
way as an FTDI chip, but with one crucial
disadvantage for me – Mac computers don’t
come with a CH340 driver. This should be a
simple fix: just download and install the
appropriate driver, but one must be careful:
there are versions of the CH340 driver
floating around the internet that have a bug
that causes a kernel panic in Macs.Unfortunately, I installed a copy of the buggy
driver on my computer, and I lost a day of
progress while fixing the problems it caused.
After getting the driver issues sorted
out, I slightly modified the Mozzi sketch I
downloaded from Instructables and loaded
it onto the knock-off Nano. Then I soldered
the Nano to a small piece of perfboard to
give myself more room to
wire things up. I selected
five of the analogue input
pins (A0–A4) and wired
each to the wiper leg of
a potentiometer. Each
potentiometer was also
connected to ground and
the 5 V pin of the Nano.
I soldered the small amplifier to the
perfboard as well, and then wired its input
pin to digital pin 9 of the Nano, which is
where Mozzi outputs audio. To power the
amplifier, I connected its supply voltage pin
to Vin on the Nano, and then tied their
grounds together. Hooking up a speaker
was as simple as sticking its leads into the
screw terminals on the amplifier and
tightening them down. I soldered a pair of
the pink LEDs to current-limiting resistorsI didn’t want to sacrifice an entire
Arduino Nano to the project,
so I opted to use a knock-off Nano
Left
Clamping and
gluing the
supports for
the acrylic