This directory contains code to retrieve a collection of image-data from a remote HTTP-site and display it upon a 4.2" epaper display.
The code works indirectly, rather than making a simple request for a JPG, a PNG, or some other known-image format it instead fetches a file that contains drawing data.
To display a specific image you need to process it, to create a data-file.
The supplied files beneath util/ do that. In the example we fetch the following two URLs:
- http://plain.steve.fi//Hardware/d1-epaper/knot.dat
- Which corresponds to the image http://plain.steve.fi//Hardware/d1-epaper/knot.png
- http://plain.steve.fi//Hardware/d1-epaper/skull.dat
- Which corresponds to the image http://plain.steve.fi//Hardware/d1-epaper/skull.png
These were each created via the utils/export script, for example:
./utils/export ./knot.jpg > knot.dat
You can transform in the opposite direction via:
./utils/import ./knot.dat
display knot.dat-out.png
To make this example complete you'll need to install two libraries:
Installation instructions are outside the scope of this document.
For details of wiring, and an overview of the whole process please see the following writeup: