■ The schematic for the BalloonSat Mini 3.
■ The schematic for a BalloonSat
Mini 2 with its camera relay.
Minis is the configuration of the third
I/O port. The Mini 3 has three I/O
channels, all capable of digitizing
sensor voltages at either eight or 10
bits of resolution. I recommend using
female receptacles for the first two
I/O ports and a three-pin header for
the third. That way, a servo can easily
connect to the Mini 3. However,
even with its three-pin header, a third
experiment can still be connected to
the Mini 3; it just needs a connector
identical to the ones used on servos.
The Mini 2 has two I/O channels
since its third I/O port operates
a camera via a reed relay. I
recommend using female receptacles
for both I/O ports, although there
isn't any reason one couldn't use a
male header instead. A modification
like that would make the Mini
suitable for one sensor, a servo, and
a camera. As you can see by their
schematics, the Minis are pretty
simple in design and have a low parts
count. That's because they make
heavy use of the capabilities built
into the PICAXE-08M.
There's nothing tricky about soldering the BalloonSat Minis together.
Since they are single-sided boards,
there's one jumper wire to install
on both designs. Check out the
diagrams for the placement of parts.
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