C code to access a ublox EVK-7P and log position data. It contains a partial implementation of the UBX protocol because of number of the more advanced configruation options are not available through the NMEA protocol.
I have used this code to perform some measurements on the accuracy of GPS under various conditions. For this I used to ublox EVK-7P GPS/GNSS Evaluation kit (GNSS receiver). Ublox provides software to read data from the GNSS receiver however this runs under Windows. Did not like carrying a laptop around so I started looking for a smaller solution.
This resulted in the following setup:
It consists of a RaspberryPi running custom software to configure the reciever and to log the position data from the GNSS receiver. The GPS reciever and powerbank to power both the RaspberryPi and GNSS receiver.
Everything is started when power is applied to the RaspberryPi. After this the following happens:
- The Pi boots and automatically starts the monitor program.
- The monitor program will run for an hour and store the results in a log file.
- After this the RaspberryPi will automatically shutdown so the power can be removed safely.
On the RaspberryPi, under the pi account create a directory GNSS.
Then copy everything from the src directory from this repository to this
directory. Run
make
This should create the executable mon.
To be able to automallically start the monitor program when the Pi is started up add the following line to the crontab of root
@reboot /home/pi/GNSS/start_experiment.sh
using
sudo su
crontab -e