[Scott-28] recently sent in a particularly well-documented project that turned an antique rotary phone into a digital kitchen timer using an internal Arduino.

The trickier part was getting the original bells to work — in North America, it takes up to 90 VAC to get a phone’s ringer going, which is quite a bit more than the lowly Arduino can handle.

This one caught my eye on twitter - a Redditor has converted a 1961 Western Electric Model 500 telephone into a rotary cell phone using Arduino.