The tracker configuration is done via a small text file on the “boot” partition of the SD card. This partition is a normal FAT (Windows) partition so it can be edited by placing the SD card in the SD card reader of any Windows PC or Mac. Alternatively it can be edited from the Pi.

From Windows

Open the SD card from Computer, where it appears as a drive letter (e.g. E:) labelled “boot”. You will see something like:


Open the pisky.txt entry, which will look (depending on version) something like this sample:


You can change the values (within limits – see restrictions below) but do not change anything else.

  • payload – This is the name of the flight, as shown on the live map. Keep it to no more than 6 characters if you are going to transmit images
  • disable_monitor – Set to “Y” to disable the monitor outputs, saving approx 20mA @ 3.3V. Do NOT use if you use a monitor connected to the Pi!
  • frequency – Used to set the radio transmission frequency, in MHz.
  • camera – Set to 1 to enable the camera transmissions, or 0 to disable them. With either setting the camera will still be used for hi-res stored images (assuming a camera is connected). Only the Pi cameras (standard or Noir) are supported
  • low_width/height – the dimensions of images taken at low altitude. It’s best to keep the same aspect ratio (1.333), and both values must be multiples of 16.
  • high – altitude above which the system uses the high_ settings instead of low_. in other words, it allows the tracker to take larger images once airborne
  • image_packets – This is the number of image packets sent for each telemetry packet. “4″ provides a good compromise between image throughput and the delay between telemetry updates
  • enable_bmp085 - Omit the line, or set to "N" or "No", to disable use of a BMP085 or BMP180 pressure sensor.  Set to "Y" or "Yes" to enable.  This device is not included on the board.  Instead the board has I2C connections (Vcc/GND/SDA/SCL) for connection to an external BMP085/180 device.  See this page for details.
  • logging - this controls what gets logged to the SD card.  Options are "GPS" and "Telemetry", and create gps.txt  (positions from GPS) and telemetry.txt (radio telemetry sentences).
  • enable_bmp085 - Enabled the code for the BMP085/180 pressure/temperature sensors.
  • external_temperature - Sets which DS18B20 is used for external temperature measurement.
  • info_messages - sets the number information messages sent over the radio when the program starts.  Default (i.e. line missing or commented out) is 4 for baud rates of 300 or higher, and 2 for lower baud rates.


From RPi Terminal

Edit using this command (or replace “vi” with “nano” if you prefer that):

sudo vi /boot/pisky.txt


Deleting Images / Log Files

Create the file /boot/clear.txt, either from the Pi (sudo vi /boot/clear.txt) or by inserting the SD card in a PC.  The contents of the file do not matter.

Next time the tracker program is started, the image files and log files will be deleted, as will the clear.txt file itself.  i.e. it's a one-shot use.  This prevents the images from being deleted again if the Pi is accidentally rebooted.

The deleted files are:

  • SSDV images (/home/pi/pits/tracker/download/*.jpg)
  • Full-size images (home/pi/pits/tracker/keep/*.jpg)
  • GPS log file (home/pi/pits/tracker/gps.txt)
  • Telemetry log file (home/pi/pits/tracker/telemetry.txt)


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