1 2 3 4 5 6 7 8 9 10 11 12 13 14
Fig. M: Schematic diagram for the time-delay controller
circuit. (Download a larger version at makezine.com/15/
diyimaging_remote.) Fig. N: Schematic diagram for the
off-the-shelf BASIC Stamp board, courtesy of Parallax;
the PIC microcontroller is second from right.
Fig. O: The circuit board in the enclosure with all
the switches connected.
I used a DPDT for the microcontroller’s power and
to disconnect the radio’s call button from P1 when
the controller is off. I also used an SPDT switch to
disconnect the transistor’s base from the speaker,
and ground it instead, when I don’t want the controller to detect a signal. Then the SPST switch can
disconnect the camera’s ground from the relays
when I don’t want the controller to be able to take
a picture. These last 2 switches aren’t needed, but
they can be handy when troubleshooting.
8. Program the microcontroller.
Connect the serial adapter to the 3-pin header
(shown at right), and use a BASIC Stamp editor
(free at parallax.com) to write and download the
microcontroller’s code (from makezine.com/15/diy
imaging_remote). Be sure that the “<<” symbol on
the adapter lines up with the grounded VSS pin.
Use a scrap of foam to hold the battery in place,
and seal the enclosure.
My radio has a detachable belt clip, which I hot-glued to the enclosure. I added a Gorillapod tripod
(see page 151), and I’m all set!
9. Go long!
To take your long-distance self-portrait, aim the
camera and turn on the controller and its radio.
Then take a second radio, tuned to the same
channel, and go get into the frame. When you’re in
position, press the call button. Once you hear the
acknowledgment tone, you’ll have about 8 seconds
before the picture is taken. A second tone will let
you know when the cycle is complete.
If you plan to leave the setup unattended for a
while, add a note with an explanation and a phone
number, so that no one calls in the bomb squad!
Tom Rodgers is a physics teacher and robotics coach in
Virginia Beach, Va. He has been a MAKE subscriber since
before the first issue was published.