How to ‘check in’ without interrupting your camino?

The question was:

Well-meaning folks are asking that I keep them posted, (check in on social media) while on my walk. I’d prefer not to touch a screen or keyboard the whole 18 days at all if I could. 

Has anyone found a very minimally invasive way of letting your people know you’re alive while on camino?

Read all the comments on the forum on the topic of “How to check in” without staying connected here.