Red phone operator bot project#

Last tended 2026-02-28

NEWS BULLETIN: the Red Phone has been "dissappeared" by the USPS. See the details about that and learn about the replacement phone on the black phone project page. This page will be preserved in homage to the Red Phone.

A new trend in wedding receptions is to have a vintage-looking phone, by which guests can leave a message of well wishes. My daughter and her fiancée challenged me to make a one-of a kind variant for their special day.

Here is a quick outline of the completed project:

• Built upon a late 70's Western Electric touchtone phone
  • Salvaged (and re-integrated) components
    • keypad
    • handset coiled cord
    • handset earpiece
    • handset cradle switch (indicates on/off hook)
    • housing and chasis
  • New/modern components
    • Omni-directional electrical condenser microphone (as handset mic)
    • Libre Computer AML-S905X-CC single board computer with 128GB eMMC storage
    • Sabrent USB Sound Adapter (for mic input and handset earpiece output)
    • Various LEDs, resistors, and capacitors needed to integrate components
  • The handset cradle switch and the touchpad signal are integrated to the single board computer via its GPIO (input/output) pins
  • The software "brain" of the phone is written in Python
    • The phone requires a wired network connection only for 1) pulling down software updates, and 2) uploading the guest recordings to a cloud repository. It is otherwise coded to operate without network access.
• The phone provides the following options to the user:
  • Record a message for the wedding couple
  • Hear a fun sample greeting from one of the wedding couples' siblings
    • Cycle through fun sample greetings from the rest of the siblings
  • Repeat the menu
  • BONUS: be teasingly scolded if you press a non-allowed key
• For each of the prompts, the phone employs audio clips recorded by the couple
• Cosmetic details:
  • Those of my generation may recall the keypad faceplate of this phone was always a gray-colored plastic. Because the faceplate of my phone had some staining to the gray, I chose to remove that coloring using acetone.
    • Bonus: I was left with the translucent finish you see in the photos.
      • The translucence cried out for the gratuituous use of LEDs:
        • white: system power
        • red (flashing): system is recording message
        • blue: linked to pressing a keypad button
        • yellow: handset is on hook
        • green: handset is off hook
  • To bring the red plastic back to life a bit, I polished it gently with blue jeweler's rouge on a cotton-muslin buffing wheel

For geeks who may be interested, this project is held in a GitLab repo. The repo is currently private, but I intend to de-indentify the relevant elements and then make the project public in the future. Use the site contact info or post a comment below if you have questions or wish for the project to be public sooner.

---

Leave a comment
Submissions are subject to review and approval