retrofitting a rotary phone for use with a computer

a normal rotary phone, right?

The story

a friend with a wedding coming up wanted a rotary phone that could play back a greeting to guests, and then record a message from them.

(a themed "retro" wedding)

So, I figured that is easy enough to do.

The solution

I gutted the phone of most bits, I didn't need the ringer, or the usual "brain" it had before.

All I needed was something to play back sound, and record it.

The solution involves putting in a new mic into the phone so the audio is higher quality for recordings, and adapting the existing speaker to a USB audio interface via a 3.5mm jack.  

(I know, I missed focus on this shot)

The new mic is just something I had laying around that fit into there - as the existing mic, while I did try it, was pretty horrible and not what you'd want for a wedding.

like an 80s Wendy's mic

Detecting handset pickup/put down I just used a simple switch to detect it.

This will be read by an Arduino (or ESP32 that is currently in there), and then when the button triggers, it will send keystrokes to a PC.

This is all plugged into a USB hub and hidden inside the phone, with a single USB cable out.

I'll run a recording software on the PC, along with maybe something like RTX voice/NVIDIA broadcast to filter background noise away, and trigger playback via a custom program on the PC side, then after that is done, record until the keypress to stop is triggered.

Pretty simple in execution, although not fully finished it does work as a nice little "handset" for the PC, hearing audio out and inputting it in at a better quality now.

Using a pro micro, to emulate keyboard presses is what I actually ended up doing, and then just timing it to the voice greeting, using a global hotkey in VLC player for start/end and just opening a folder/playlist with just the greeting (with a BEEP at the end of the audio).

Then it triggers audacity to start recording, and then lights up an indicator light too for recording started.

Long run I could probably make this an all in one solution easily enough with a raspberry pi, even without needing extra programs on the pi just hook it in to the arduino pro micro.

It also has RGB underglow.

why not, right?  I lied. I removed the underglow.