For my Physical Computing final, I needed to hack an old telephone that will be used to interact with a pile of electronic junk.

This telephone needs to plug into my audio interface, as well as house an Arduino to broadcast information about where the receiver.


  • Dremmel
  • Microphone
  • Speakers
  • Old Telephone
  • Helping hands
  • Drill Press
  • Clamp


First, I opened up the telephone to find that I would need to create some space.

I decided to take the bottom of the telephone with a drill press to remove the old metal ‘plug/screws’.

After a bit of trial and error with the drill bit, I found one that worked. I used a clamp to secure the telephone, and prepared the drill press.

It was obvious when the drill released the ‘plug/screw’ - It works great!

I removed the heart of the phone, which created the perfect amount of space for my Arduino and speakers.

The next step was to modify the receiver so that it could communicate with my audio interface. I removed the existing microphone.

I cracked open a dynamic microphone, and removed the microphone part. This piece was too large to fit inside my telephone receiver, so I needed to use the Dremmel to cut it down to size.

(Apologies for the lack of photos, I forgot to document this process)

I soldered the new Microphone to the telephone receiver, and connected this to the Arduino enclosure.

It works!


I am considering wiring up the Arduino directly to the ‘bells’ instead of faking the ‘ring’ with speakers, however I’m not sure this is the best use of a half-day/days work. The case seems to create a nice amount of resonance, even without ‘speaker holes’.