labthings-picamera2 0.0.1.dev1

Picamera2 support for LabThings-FastAPI

labthings-picamera2

A LabThings-FastAPI Thing for working with picamera2

This package defines a Thing using labthings-fastapi that exposes an HTTP interface to the Raspberry Pi camera, using picamera2. This includes autogenerated OpenAPI documentation viewed with a built-in Swagger/Redocly page at /docs/, and a Web of Things compliant Thing Description at the camera's root (usually /camera/).

Installation

For this to work you should be on a 32-bit version of Bullseye or Bookworm os with python v3.9 or 3.11.

It's usually best to install in a virtual environment, but note that you should use

python -m venv .venv --system-site-packages

as the picamera2 package and its dependencies are not all installable using pip.

The package is on PyPI and can be installed using

pip install labthings-picamera2

You will also need to separately install the server with:

pip install labthings-fastapi[server]

If you want to edit labthings-picamera2 then you can clone this repository. Move to the directory and run

pip install -e .

Usage

You can start the server using:

labthings-server --json '{"things":{"/camera/":"labthings_picamera2.thing:StreamingPiCamera2"}}'

This assumes you have labthings[server]>=0.0.6 installed.

You may then point a web browser at http://localhost:5000/camera or http://localhost:5000/docs/.

It's also possible to control it from Python, if you have labthings-fastapi installed (note that if you're using a separate machine or separate environment for the client, if you don't add [server] it won't install the rather heavy server dependencies like starlette.)

To connect, run:

from labthings_fastapi.client import ThingClient
from PIL import Image

cam = ThingClient.from_url("http://localhost:5000/camera/")
blob = cam.capture_jpeg()
image = Image.open(blob.open())

All of the properties and actions described in the Thing Description should be present as Python properties and methods - currently the types and docstrings don't propagate to the client object, this is planned for the future but isn't reality yet.