QRD: Quantum Rotary Dial, Part 1 – A Quarantine Project

As with many other people around the world, I’ve been self-isolating for the past decade. Or at least, it feels that long. I decided to put this extra time to good use by pursuing projects and passions I would have otherwise only dreamt about.

I wanted a project which would involve hardware and software; would push me to learn new skills and technologies; and would be fun. After all, this is meant to be an enjoyable experience.

I got the idea it’d be pretty cool to repurpose a rotary dial telephone to be an input device for my computer. So, I came up with a game plan:

  1. Research
  2. Build
  3. Program

Research Phase

In this phase I wanted to answer the following questions:

  1. How much are rotary dial phones?
  2. Has this been done before? If so, how did they do it?
  3. What are the components I’d need?

Finding the phone

The first question took priority because I didn’t want to spend an astronomical amount on what’s essentially a toy. I didn’t have a clear use-case for the end product. This was more about the journey, or the learning experience, than anything else.

A quick glance at ebay revealed a wide range of prices for rotary phones. I could find something reasonable for me.

I settled on a vintage 1970s ITT Model 500 Series in chocolate brown, as seen in the picture above.

On the shoulders of Giants

I’m a firm believer that we should build on the knowledge of others. Often times, we’re not the first person to encounter the problem and, with any luck, a solution might already exist.

A few evenings of internet searching revealed a number of interesting projects on rotary dial telephones.

rotaryX: A Question and Answer Machine

Link: https://www.instructables.com/RotaryX-How-to-Hack-a-Rotary-Phone/

This project is awesome. It gives you full control over every aspect of the phone: dial, hook, ringer, and receiver.

It’s also much bigger in scope than I’d originally planned. I really only wanted to use the rotary dial part.

Rotary Contoller Dials in PC Volume

Link: https://hackaday.com/2020/06/04/rotary-controller-dials-in-pc-volume/

Sometimes, the stars align. I’d started researching on June 5, 2020. This article was published on June 4, 2020. This project was extremely close to what I’d envisioned. I wasn’t going to remove the dial from the phone and print new case, but I was confident that the components would fit inside the original housing.

Within the article is a link to the Instructables by Cameron Coward: https://www.instructables.com/Vintage-Rotary-Phone-Dial-PC-Volume-Control/

It was everything I needed to get started. I was ready to start building

Purchasing Parts

Thanks to Cameron’s instructables post, I knew I needed the following:

  1. A rotary phone
  2. Arduino Nano
  3. Resistors (470 ohm and 10k ohm)
  4. Solderable bread board

The resistors and bread board were nominal cost. The phone was $20 (plus shipping and tax) and the Arduino cost me $17. So in total, this project cost about $50.

Next: Build Phase