Want to build a $10 sensor that notifies you if a door or window is opened? In this video I show how I've made door sensors for around my property, with an #esp32 and a reed sensor. These are cheap components you can get from #aliexpress or #temu for under $10 and you can make this in an hour with a little bit of #arduino coding. In my case the notifications are sent to #discord , but I have previously sent them as an SMS by sending #mqtt into #aws #iot core and then using SNS with an SMS target. It just got a little expensive that way so Discord was cheaper. Code for this demo is here: 00:00 - Intro 00:22 - How it works 01:20 - What you need 05:10 - The code 12:10 - Demo