Common Problems - esa-prl/ExoMy GitHub Wiki

Here is a compilation of commonly occuring problems. It is not complete and should be extended as the project progresses.

In case, the problem is not solved by checking here and in the other parts of the wiki consier submitting an issue or ask your question on Discord.

I have no WiFi!

It might be, that you installed the Raspberry Pi with four metal standoffs instead of three as recommended here. The metal from the standoff and screw will drasticily reduce the performance of the wifi antenna. A plastic or nylon standoff and screw is fine however.

My motors don't move.

Make sure the motors switch is turned on.

My rover doesn't start.

• Make sure the battery is charged.
• When turned on the red (power) LED of the Raspberry Pi should be stable and the green (SD card activity) LED should be blinking irregularly.
• Try connecting a screen and see if the Raspberry Pi works. Restart after connecting a screen.

Nothing appears on the display.

The HDMI cable has to be connected to the Raspberry Pi before bootup in order for it to display the desktop.

Rainbow Colored Screen

If you only see a rainbow colored screen, the Raspberry Pi got stuck in the boot process. Best option is to flash the SD card again.

ROS cant find files

Try sourcing the ROS development environment again with source devel/setup.bash. This command should be executed in the exomy_ws. That's needed when a new terminal is started.

Possible Python-Error Message

If you get an error message: bash: python: command not found add a 3 to python:

python3 config_motor_pins.py

This applies to then to all python commands. Replace "python" in the command by "python3". This wiki describes multiple setups and software versions, so it is possible that in a newer version, Python 3 instead of Python 2 is used.

Useful Terminal Commands

Command	Description
rm [file name]	Removes the given file, add -rf to remove a folder
cd [destination]	Changes to the given folder, leave destination empty to jump to root folder
ls	Shows the files within the current folder.