I have a raspberry pi 3 with a magnetic door sensor.
i'd like to log the data for the open/close state throughout the day and then have it either posted (on a web server HTML) or as a .txt file with a timestamp.
basically, i have a dog walker and I want to see what time they open and close the door, to evaluate how long they are walking him.
I know this is a pretty 'large' question describing a rather large process, but I'd appreciate any advice pointing me in the right direction. I'm familiar enough with opening ports on my router for dyndns services to go through.
Thanks very much!