Guy Dupont has created an interactive telephone prop using our favorite microcontroller, the Raspberry Pi RP2040. According to Dupont, he was commissioned to create this prop for the Stranger Things season 4 premiere event, but that the booth it as to be featured in wasn't use.
(It’s also worth noting that beyond a few private emails, Dupnot didn't provide any verification that he was actually commissioned by the team for this project, but we still think this is a cool project worth showcasing.)
Dupont explains the vintage phone was planned to be positioned in a booth resembling a 1980s pizza shop. What looks like an unassuming prop would occasionally ring. When guests pick up the phone, they would hear random sound bites from the show, scary sound effects and even random pizza orders. Lifting the phone off the hook returns a dial tone sound, the buttons work with an audible sound for each keypress and the speaker will returns a disconnected sound once a number has been dialed.
If you haven’t heard of Dupont before, you should definitely check out his project history. Dupont is a software developer and audio engineer with plenty of experience in microelectronics. You can find more of his work on Hackaday as well as videos of his work in action over at his official YouTube channel.
The project is designed to use a vintage ITT phone and as much of the original hardware as possible which includes the dial pad, receiver and hook. The audio logic is handled using a Sparkfun RP2040 Thing Plus along with an Adafruit UDA1334A breakout. Sound bites are played through the earpiece in the receiver while a 3W speaker is used for the ring effect.
The software was designed from scratch by Dupont using CircuitPython—which recently hit a milestone with official support available on over 300 boards. There are three main audio banks it pulls sounds from including the ring effect, sound bites for the earpiece and various tones that replicate the classic phone interface.
If you want to recreate this Raspberry Pi project or just get a closer look at how it all goes together, check out the full project thread over at Hackaday and watch the project video shared to YouTube to see it in action. We also have an awesome Stranger Things Christmas Lights project tutorial designed by Ryder Damen to compliment the vintage phone designed by Dupont.