Dogwood Apps Rasberry PI, User Manual

Page: 54 / 59

consumption down and to minimum, we need to ‘underclock’ the Pi by adding:
arm_freq=300
Hardware setup
Raspberry Pi camera
The Raspberry Pi camera is a 5 MP device and is connected to the CSI port of the
Raspberry Pi via a flexible flat cable.
We will be using Model-A as it consumes less power and can be housed into a small
enclosure. Once you have installed Raspbian on your SD card, insert it into the SD card
slot of your Raspberry Pi. Now connect your Pi with camera using CSI, monitor with
HDMI, keyboard and mouse with USB, and connect to power supply.
Allow your Pi to boot. We will now add capture script.
Capture script
The command /opt/vc/bin/raspistill is used to capture still images. You need to put this
simple script (script is taken from DesignSpark) to run raspistill in a loop:
ROLL=$(cat/var/tlcam/series)
SAVEDIR=/var/tlcam/stills
while [true]; do
filename=$ROLL-$(date -u +”%d%m%Y_%H%M-%S”).jpg
/opt/vc/bin/raspistill -o $SAVEDIR/$filename
sleep 4;
done;
Every time the Pi boots, above script is executed and it captures an image every ten
seconds (approx.).
The image file name comprises a number, determined by the variable $ROLL, which can