On 2016-03-14 12:06, bruno suarez wrote:
Hello,
For a stratospheric balloon project, I usea raspberry Rasbian Jessie and
a USB GPS receiver.
Everything is OK with gpsd and my GPS receiver.
When I plug everything works correctly, gpsd start on the correct port
/dev/ttyUSB0.
However, I want to make sure that everything works properly during 2/3
hours to extremely cold temperature
What is the easiest way to automatically control the operation of GPSD
and relaunch it(on the same port detected ) if it is stopped or if it is
in error.
Thank you for your answers and tips
Cordially
Bruno
First, pack your payload with heaters. You can use chemical heat packs
from a pharmacy that are normally used for heating muscles and joints
(these are the plastic bags that you smash to mix the chemicals and they
get warm.) In an insulated container you should stay within your
operating limits of the Pi (the lower limit is approximately -20 Celsius).
After that, just set up a script that watches for data coming from gpsd
and, if there is no data, issue a kill for the PID of gpsd and restart
it. Since gpsd can support more than one connection you can get data
for your recording/telemetry program and have a completely separate
program running to watch for a loss of communication.
Also make sure to enable the watchdog timer in the Pi so that it will
reboot if the whole system fails. Make sure gpsd will start at boot as
well as your data logging/telemetry program and the monitoring script.