GrowHat screen doesn't work due to missing ltr559 module


I can’t get the GrowHat screen to work, likely because of a missing module.

When running:

I get:
Traceback (most recent call last):
File “/home/jmcmillon/Pimoroni/growhat/examples/”, line 10, in
import ltr559
ModuleNotFoundError: No module named ‘ltr559’

pip install ltr559

Throws the following error:

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
python3-xyz, where xyz is the package you are trying to

If you wish to install a non-Debian-packaged Python package,
create a virtual environment using python3 -m venv path/to/venv.
Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
sure you have python3-full installed.

What’s the best way to get this module installed?


Bookworm has changed how Python modules need installed. You can find more information about how to work with it or around it in this thread: St7789 install error with Bookworm?

Pimoroni needs to update its GrowHat instructions at

and its code referenced by
curl -sSL | bash
to either make their code work under bookworm,
or to warn users to use previous bullseye instead.

The new Python Virtual Environment is (for me anyway) a PITA. At the moment I’m running Legacy on anything that isn’t a Pi 5. It just makes life easier on this old brain.
Pimoroni is playing catchup in terms of installers and instructions etc.

I think you have to keep in mind how large their codebase is, and the size of changes that appeared with Bookworm.

In the meantime, there are procedures for persuading the Grow Hat to play nicely :)