Vintage phone AI assistant Ramazan Eren Arslan converted a Deutsche Bundespost FeTAp 791 rotary telephone into a voice assistant, with the build documented on Hackster.io. Lifting the handset and speaking routes the query to Google Gemini, which answers through the phone's original earpiece, with a Raspberry Pi 3B installed inside the housing in place of the original PCB and the hook switch wired to GPIO. Ramazan Eren Arslan turned a Deutsche Bundespost FeTAp 791 rotary telephone into a voice assistant, with the build documented on Hackster.io. Lift the handset and talk, and Google Gemini answers through the original earpiece. A Raspberry Pi 3B sits inside the phone where the original PCB used to be. The hook switch wires to GPIO …