User:Wordfa/oldphonehack

Phone Hacking Project

Project for SS25 to create a story gathering system using an old phone.

T65 Rotary Phone bought by Sevgi n' Fred

Parts Required

USB interface to 3.5mm

https://www.adafruit.com/product/1475

3.5mm Cables

Old phone (T65)

https://www.marktplaats.nl/v/telecommunicatie/vaste-telefoons-niet-draadloos/m2158407457-ptt-t65-goed-werkende-nostalgische-telefoon

Raspberry Pi

TRS 3.5 Jack x2

Wire n stuff

old headphones with a mic (apple earpod style)

Things we done

We took the phone apart and got the speaker to work by connecting the blue and red cables from the phone out to the audio jack to the soundcard to the computer. played show me the body, was good.

[11 (Neg), 12(Pos) speaker output]

Then we tried the microphone but its a carbon mic and it didnt work. so we atttached a battery and hoped. didnt work.

We took apart wired headphones that had mic in them to see if we could use the mic from it rather than the carbon mic in the telephone.

didnt work, headphone cable is TRRS not TRS:

spent a day trying to wire up TRRS to an audio cable, turns out the audio jack was the wrong kind.

then wired it directly to a TRS jack, worked!!!!!!!!!!!!!

then cable managed, looks beautiful now. now we have working speakers and working mic.

This is how you could make it work too:

From the headphones you need to...

Connect th Blue (Ground) to the Sleeve of the TRS jack

Connect the Red (mic) to Pin (Ring) 1 or 2 of the TRS

MAKE SURE THE HEADPHONES CONNECTION IS CLOSED!

The wiring used

Sketch here:

Next Steps:

work out how to read the keypad input on the raspberrypi. like it is documented here: https://www.jwz.org/blog/2016/01/my-payphone-runs-linux-now/

References

Microphone from handset

https://www.youtube.com/watch?v=rIkIkbOw3OQ&t

Rotary Pi

• Really good write up with code:
• https://marks.kitchen/blog/rotary_phone_running_linux/
• Linking Video
• https://www.youtube.com/watch?v=M4eCrctDMEc

Lofi Mic

https://www.youtube.com/watch?v=7gorBkdk8zY

Schematic (v scary)

https://easyeda.com/editor#id=7d0350ec43844219912695cec1a0e156

Rotary MP3 Player

https://www.whizzbizz.com/en/gpo746-t65-rotary-dial-phone-mp3-wav-player

Info on the T65

https://www.cryptomuseum.com/phone/t65/index.htm

Carbon Mic https://www.youtube.com/watch?v=cwPPoVvljOw

Weird Stuff

how does a carbon mic work

https://wonderfoon.jimdosite.com/

https://www.youtube.com/@ruudshangout/search?query=t65