Back in the days of yore when hats were fashionable and color TV didn’t exist, there were real life people who would answer the phone if you dialed 0. These operators would provide directory assistance, and connect you to another number (such as KL5-8635). Apple’s Siri is a lot like an olde-timey phone operator, so [davis] decided to put Siri in an old rotary telephone.
The build started off with a very inexpensive Bluetooth headset and very old rotary phone. The single button on the Bluetooth headset was wired to a contact of the dial – in this case, the number 1. Dialing 1 shorts two contacts in the phone and the Bluetooth headset turns on.
[davis] came up with a very easy build but dialing 1 just isn’t the same as dialing 0. Connecting the Bluetooth button to 0 closes the button for too long. He says ‘0 for operator’ could be implemented with an ATtiny or similar, but we’re wondering if [davis] could make due with a dial-less candlestick phone.