Florin was tired of wasting batteries every time he forgot to turn off his multimeter. He hacked together an auto-shutdown:
I bought this multimeter(Minipa ET-870C) a while ago for $17, great value. I got it because its nice to have around multiple meters for when you wanna measure both input and output voltage/current. I believe it was advertised to have an auto-off feature for 15 mins but it didn’t. This eventually lead to many drained batteries because I often forgot to turn it off after using it. So during a boring weekend when the weather outside was bad I decided to add this nice feature to the meter. I knew it had to be a small circuit to be able to fit inside the multimeter so I picked the tiny25 the smallest micro I had around.