Where feasible, TRMNL connects natively with popular calendars to minimize data exposure. Google and Microsoft Outlook are 2 examples, with more available through Apple Calendar and TRMNL Companion.
Some calendars however, for example Proton, cannot be integrated as securely due to E2E (end to end) encryption. For this case we support the CalDAV / ICS protocol.
Unfortunately, ICS calendars share all events (past and future) to connecting platforms, with no ability to scope the data. That's where Home Assistant can help limit exposure.
Prerequisites
Home Assistant running on your local network
A calendar that supports shareable ICS links
Step 1 - Install CalDAV
Open Home Assistant -> Settings -> Integrations -> Install CalDAV.
Add ~any calendar you'd like, using app-specific passwords where possible.
Step 2 - Install TRMNL
Add our native Home Assistant integration:
https://help.trmnl.com/en/articles/13281388-home-assistant-screenshot
Step 3 - You're Done!
Raw calendar data will only be available locally, with just the events' titles and date/time shared with TRMNL in screenshot format.