Merging multiple calendars on ESP32

[Larrys]

Hi all
I’m messing about with an ESP32 for a wee home automation project and want to pull together a few different calendars so the microcontroller can trigger stuff at the right times. Ideally, I’d like to grab several feeds, like Google Calendar and Outlook, and merge them so it knows when certain things are happening. I’ve been looking into ways to sync multiple calendars and filter what info gets shown – like hiding details or just seeing availability – but it seems a bit of a faff if you want to handle multiple accounts and keep everything updated. I was thinking to use a google and microsoft calendars synchronisation tool for make it easier, but I'm not sure how it'll behave with the ESP32. Has anyone had a go at this yet? Would be grand to hear what libraries or methods folks have used for automatic sync and keeping data private.
Cheers for any tips, even bits and bobs, it’d really help me sort out my code and approach.

[lichurbagan]

Use Google Calendar as the main hub. Import Outlook there. Then fetch one ICS feed on your ESP32. This avoids OAuth pain. Parse the ICS with a small parser. If you need more control, use Node-RED or Home Assistant. They can merge feeds and hide details. Output a small JSON file. Let the ESP32 read that. This keeps things simple. It also keeps your data private. Direct API use is heavy. Avoid it on microcontrollers. A small middleware server is easier.