The tree arrived last Sunday and with it my age old worry about it drying out before Christmas. In a house as busy as ours this is a big issue.
Enter Atmels ATTiny85. This is a small easily programmable micro controller for under $2. Just add a coin cell battery an led, buzzer, battery, some wire and a box to put it in and you’ve got a low water alarm that sings Jingle Bells when the water gets to low.
Below are some pics of the almost finished product. And here is the link to the project.