Starting the Rover with a Button

When autonomous driving competitions, typically the Rover must be handed to the judges at time of race and no more modifications or remote connections can be made to the Rover. Competitors must simply turn on their vehicle, set it down on the track and press START. But how can this be done given that we require to use roverctl to start and stop pipelines?

Niels Dijkstra

Teaching assistant

Max Gallup

Hardware Lead, Project Administrator

info

This page contains only relevant information for students wanting to participate in the NXP Competition. This tutorial assumes you are able to connect to the rover and copy or move files on it. For more details read connecting to the rover.

For this we provide a mechanism that let's you declare a pipeline in a file and even select up to three different service.yaml configurations by pressing the button on the Rover. For example, your race-logic must all be in a custom service called "controller" and you want to select between two different top-speed settings. For this you will have have two different copies of your original service.yaml in files called profile1.yaml and profile2.yaml with fast and slow values for your top-speed. Then, at the time of racing, you will be able to choose between the two profiles by pressing the button. Since the rules of the NXP-Cup allow you to try again after a failed attempt, it might be wise to choose a slower speed setting for a second try so that you increase chances of completing the lap.

In short, after turning on the Rover, you will be able to select up to three different "profiles" which are just copies of a single service.yaml for the controller service. And after selecting the profile, you finally confirm your choice with another button press and the Rover will start racing.

race.yaml

In order for the rover to know which pipeline you are running, you must specify it in a file named exactly /home/debix/race.yaml. You specify a list of services in the form "author/service/version". Example:

pipeline:
  - vu-ase/imaging/1.2.1
  - vu-ase/actuator/1.3.0
  - your_team/controller/1.0.0

Then, since there is a service in this pipeline called "controller", we can specify anywhere between 1 and 3 profiles in the root of our controller's directory. These files must be named profile1.yaml, profile2.yaml and profile3.yaml. For example, the controller's file layout might look something like this:

/controller
    ├── /src
        ├── main
    ├── service.yaml
    ├── profile1.yaml
    ├── profile2.yaml
    ├── profile3.yaml
    ├── other files...

The original service.yaml will be overwritten

Important: since the content of the profile.yaml files will be copied into the service.yaml when starting, so don't save any important configurations in the original service.yaml. Save all your configs in the profileX.yaml files.

For example, if you select the first profile then the contents of profile1.yaml will be copied into service.yaml.

Selecting a profile

Once the Rover has booted up a light will appear to the left of the screen. Press the button to the left of the screen and notice how the light will move from one spot to the right, wrapping back around. The initial LED indicates that profile one is selected. The middle LED indicates that the second profile is selected and the third LED selects profile three. Once your selection is made, hold down the button until the rover starts beeping. If no problems arise, your pipeline will start in seconds.

Enabling it

The button pressing menu is done by a program saved on the Rover called /home/debix/ase/bin/boot.py. You can test the process by running the script directly on the Rover.

rover03 $ python3 /home/debix/ase/bin/boot.py

To enable this script on boot, we need to tell the debix to run this script after the kernel has fully initialized. To do this, append the command to the file /home/debix/ase/bin/system-start. The following command does exactly that:

rover03 $ echo "python3 /home/debix/ase/bin/boot.py" >> /home/debix/ase/bin/system-start

Troubleshooting

If it fails to start a pipeline, it will start beeping. If beeping starts before you can select a profile, race.yaml is likely missing from the rover. If this is the case, consider ssh-ing into the rover and fix the problem:

rover03 $ cat /home/debix/race.yaml

If the rover starts beeping after selecting your profile, it likely means one of the following: Either your profile was not found, you don't have a service called controller or there was an issue in your race.yaml. If the error is not clear, you can test the boot procedure manually by running the boot.py command on the rover.

Finally, if your rover does not start a pipeline but also does not start beeping, this could mean your binaries were not set up (correctly). Try running your pipeline once by using roverctl, as this should hopefully resolve your issue.