SD Card Image From Scratch


SD Image

First, download the a Raspbian Lite image from the RPi download page, and install on an SD card of 8GB or larger, following these instructions.

Only Raspbian is supported.  We test each new version soon after it is released, but be aware that if you use a release that is very new then you may well be the first person to try it with PITS!  Probably better to wait a few days.

The following instructions are for the latest version of Raspbian Lite (Buster - June 2019).

Raspbian Configuration

We recommend use of a B+ or V2 B Pi for setup and testing, though you could also use an A+ or Zero with a USB wired LAN adapter.  Wireless LAN is more tricky to set up so wired is preferred.  The V3 Pi is now also supported but is more work to configure (see below) *and* will get hot in flight.  The V4 Pi is untested and will get hotter.

Insert the SD card into your Pi, connect to your LAN, and apply power to the Pi.  Don't connect the PITS board yet.

The following steps can be done from a USB keyboard attached to the Pi, or an ssh session from another computer.  The latter is more difficult to set up but does mean that you can "cut and paste" the commands below. For WIndows users, we recommend "putty" as an easy to use ssh client.

Using either the keyboard or ssh, login using user “pi” and password “raspberry”, then type:

sudo raspi-config

You then need to set a few things, all under "Interfacing Options"::

  1. Interfacing Options --> Pi Camera --> YES OR (2022+) Enable Legacy Camera Support
  2. Interfacing Options --> SPI --> YES
  3. Interfacing Options --> I2C --> YES
  4. Interfacing Options --> Serial --> NO (login shell) and then YES (hardware)
  5. Interfacing Options --> 1-Wire --> YES

Then close raspi-config and allow it to reboot (you will be prompted for this).


Pi 3 (A+, B, B+) and Pi Zero W

You need to disable the bluetooth module, and map the freed serial port to the GPIO pins.  To do this, edit /boot/config.txt:

sudo nano /boot/config.txt

then go to the end of the file and add a new line containing this:


Exit the editor, saving your changes.

Now type this command:

sudo systemctl disable hciuart


sudo apt-get install git



Although PIGPIO driver and tools are included in Raspbian now, the dev files for compilation are not, so it still needs to be installed manually.

To install, type these commands in sequence:

sudo apt install python3-distutils
cd pigpio-master
sudo make install

The first make step takes some time to complete.


Wiring Pi

cd ~
git clone
cd WiringPi


Install SSDV Software

Now install the equally excellent SSDV (Slow Scan Digital Video) software from Phil Heron. This provides a command-line app which converts between JPG and SSDV formats. In our case we convert from JPG to SSDV and then transmit the resulting packets over the radio link. Install using this command:

cd ~
git clone
cd ssdv
sudo make install



This is only needed if you wish to use a USB webcam instead of the Pi camera.

sudo apt-get install fswebcam


Tracker Software

The PITS tracker software is on github, and can be installed as follows:

git clone
cd pits

The build process compiles and links the tracker program, creates a default configuration file, and sets the software up to start automatically when the Pi boots.



Shut down the Pi (sudo halt), remove power, connect the Pi camera (threading the cable through the slot in the PITS board) and then and connect the PITS board (click here if it's not obvious how to do that).  With the camera and PITS boards connected, apply power and wait for it to boot.

Once it has started (to the login prompt on the monitor) the tracker program and camera script will automatically start.  After a few seconds you will see the camera preview appear on the monitor, and this will repeat approx twice a minute.  Meanwhile the tracker software runs in the background.

You should see the red WARN light come on straightaway. This will stay on until the GPS receives lock, which first time could take 2 minutes or so. If after 5 minutes there is no lock, move the GPS antenna to a window, or outside. The receiver is very sensitive and you should get a lock anyway so long as it has sight of a window.

Once GPS lock has been established, the WARN LED will go out and the green OK light will flash.

At this point you should set up a radio receiver to decode the transmissions.

When you are done testing for now, you can login and then shutdown the Pi with "sudo halt".

If you want to see what the tracker is doing, then login to the Pi, then kill the tracker and restart it with:

sudo killall startup
sudo killall tracker
cd ~/pits/tracker
sudo ./tracker


Updating The Software

Periodically we update the software on github, and we do recommend that you always use the latest available.

To be informed of any updates, you need a github account, after which you can go to and "star" the repository.

Alternatively, follow on Twitter.

To download and build the latest software, perform these commands either at the Pi keyboard or in an ssh session:

cd ~/pits
git pull origin master
cd tracker


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