Hardware Reference
In-Depth Information
Whatever you choose needs to be large enough to house the Raspberry Pi, a battery
pack, your tracking device, and your camera(s), as well as any other parts you've
chosen to use as a part of the project. (You can see how space and weight can add
up!) The example payload in this hack includes the Raspberry Pi connected to:
• Video out to a 144 MHz Videolinx ham radio ATV (Amateur TV) transmitter and
small whip antenna
Trackuino
which contains a GPS, and a 300 milliwat HX-1
144.39 MHz APRS transmitter, and an Arduino for decoding and modulating the
GPS signal for the transmitter
• GY-80 I2C 9-Axis Magnetic Acceleration Gyroscope Module
• 5000 mAh USB cell phone backup battery
• USB WiFi adapter
• USB Y power cable to allow powering the WiFi directly from the battery and not
through the Raspberry Pi's weak USB power ports
• Raspberry Pi camera module
• Nikon Coolpix camera (controlled by gphoto)
The Trackuino is an Arduino-based APRS system that includes a high-altitude GPS
system and GPS antenna. The Arduino decodes the data from the GPS and then
modulates it to drive a 300 mW HX-1 transmitter, which then drives an 8 W Micro Amp
3 amplifier, which is then fed into a whip antenna. The amplifier isn't necessary once
your payload gets up high enough above the terrain, but it is helpful in locating the
payload when it's down on the ground and away from other ham radio APRS systems.
The Trackuino and Micro Amp3 are driven by eight AA lithium cell batteries (inde-
pendent of the 5000 mAh cell phone battery that powers the Raspberry Pi), which
will last 5+ hours. This separate power supply is helpful in the event that the Raspberry
Pi loses power before the payload is recovered.
The GPS signal of the Trackuino can also be routed to the Raspberry Pi so that it can
correlate the sensor data with the time stamp, altitude, and latitude and longitude
data from the GPS (you will need to disable the console port on the serial device before
doing this). The GY-80 module connects to the I2C pins and ground and 3.3 V power
signals from the Raspberry Pi.
For the Raspberry Pi battery, we suggest a 5,000 mAh cell phone backup battery. A
pack of this size can run the Pi, record sensor data, and power the camera for more
than five hours. They're lighter weight than nickel-cadmium (NiCd) batteries and can
be purchased for as little as $15. Another advantage of this as a battery pack for the
Raspberry Pi is that it has two built-in USB power outputs (one for the Raspberry Pi
and one for the USB WiFi Y cable), and a built-in power switch (which the Pi itself lacks).
