Testing Outdoors
The following section assumes you are using Piksi Multi.
If you have already surveyed the Base Station location and it is placed on the exact same spot, you can skip the section "Base Station Survey". Otherwise there are two ways to sample the base station location:
- Piksi console autosurvey, or
- ROS launch file geodetic survey.
In any case, make sure you configure the settings of the Piksi Multi that act as base station correctly: see page Settings Base Station
Attach Piksi of the Base Station to your PC and open Piksi Console. Go to "Settings -> surveyed position", click to any field in this section and then click the button on the top right corner "Auto Survey". The last 1000 GPS points will be used to compute the position of the Base Station.
After that, make sure the four fields in "surveyed position" (broadcast, surveyed lat, surveyed lon, surveyed alt) "make sense".
Attach Piksi of the Base Station to your PC and launch
roslaunch piksi_multi_rtk_ros geodetic_survey.launch number_of_desired_fixes:=3000
This will wait for 3000 samples of SPP (Single Point Position) from Piski, average them and compute the final position of the base station. Moreover it will write the sampled position (latitude, longitude and altitude) in the Piksi settings and save them to flash. A log file with sampled position is written in the folder log_surveyes.
Once you have surveyed the position of your base station you can start Piksi to the device that will act as base station. Attach Piksi to your PC, log in with ssh, start Piksi driver in base mode and let it run:
roslaunch piksi_multi_rtk_gps piksi_multi_base_station.launch
Tip: you can use the application "screen" and its detach mode. See example below.
ssh <username>@<base_station_ip>
screen
roslaunch piksi_multi_rtk_ros piksi_multi_rover.launch
You can detach from the window using "Ctrl-a", "d". You can close the ssh session and the ROS driver will still run.
When you want to stop it
ssh <username>@<base_station_ip>
screen -r # re-attach to previous session of screen
Stop the node and close screen by typing "Ctrl-a", "k", "y".
Once you started piksi_multi_base_station.launch you can power Piksi on your rover/robot.
roslaunch piksi_multi_rtk_ros piksi_multi_rover.launch
You can use rqt_gps_rtk_plugin (on your PC, not onboard the rover!) to check the status of your fix (remember to set ROS_MASTER_URI and ROS_IP on your PC, or to use node manager).
roslaunch rqt_gps_rtk_plugin gui.launch