1d. Insert the 22μF capacitor through the 2 PCB holes indicated
by (+) and (–), and solder it in place. Be sure to watch polarity;
the stripe on the cap goes on the (–) side.
1e. Insert the relay into the PCB at the forward edge so that the
single switch terminal dangles off the side of the board and the
other 3 pins run through holes. The bottom left pin should run
through the hole that’s 3 up from the bottom of the board and
2 from the left.
1f. Insert the 1N4001 diode into the through-holes that connect
to the relay coil terminals so that its body drapes over the top of
the relay. This diode protects the PICAXE from back electromotive
force when the relay is de-energized. Using jumper wires, connect one of the relay coil terminals to the PCB ground pin and
the other to PICAXE output 2 (pin 5 on the chip).
1g. Solder about 1' of 18- to 20-gauge wire to each of the relay
switch terminals. Use wire cutters to cut a 2-pin length from
the male breakaway headers, and solder the 2 pins to the wires’
other ends. Cover the solder joints with heat-shrink tubing or
electrical tape to prevent shorts and to add strength.
2. PROGRAM THE TRIGGERING
2a. Download and install Revolution Education’s free AXEpad software from
2b. Download the BASIC file
Camera_Timer.bas from makezine.
com/24/ballooncam, then open it up in AXEpad.
This simple, 14-line routine waits 20 seconds from the time
of initial power-up to give time to replace the pill bottle cap,
takes one picture to confirm that it’s running, waits another
20 seconds to let the balloon rise, then begins snapping pictures
every 2 seconds. You can modify this to suit your needs.
2c. To load this code into your Proto Board, connect the PICAXE
programming cable between your computer and the board’s programming jack, then click the Program button in AXEpad, in the