37C3 - Analog rotary phones get a second life with raspberry pi

Turn old analog rotary phones into a modern communication system with Raspberry Pi, enabling nostalgic connections and DIY innovation.

Key takeaways
  • Analog rotary phones can be given a second life using a Raspberry Pi.
  • The project aims to connect at least eight phones and allow them to communicate with each other.
  • The system uses a rotary thread to count pulses from the rotary dial.
  • The front end circuit generates signals, including the ringing tone.
  • The system uses Gstreamer to generate DTMF pulses for connecting to the Fritz box.
  • The ring trip stops the connection when someone lifts the receiver.
  • The main state machine monitors the loop close signal and counts the number of pulses.
  • The system uses a select function with a timeout to determine what’s happening.
  • The project aims to get the international feeling of the phone by using different ring tones and frequencies.
  • The author has not approached any museums or telecommunication exhibitions with the project.
  • The system uses a transformer to boost the voltage to 100 volts for the ringing tone.
  • The author is open to improving the project and making it more efficient.
  • The system uses a PCB to implement the circuit.
  • The author has not published the project and has only shared it with friends.
  • The project aims to provide a nostalgic experience and allow people to connect with the past.
  • The author is looking for feedback and suggestions on how to improve the project.
  • The system uses a conditional rate to control the ringing tone.
  • The author has not implemented the switch matrix fully.
  • The project aims to be a hobby project and not a commercial product.
  • The author is open to sharing the project with others and making it a community project.
  • The system uses a JFET for the connection matrix.
  • The author has not published the schematics for the project.
  • The project aims to provide a unique experience and allow people to connect with the past.