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Show HN: Rotary Phone Project

github.com

208 pointsmnutt46 comments

As a child growing up in the UK I was allowed to call up, each evening, the bedtime stories phone line run by British Telecom. I used to call that bedtime story phone line from an an old 1970's era rotary Snoopy telephone from British Telecom which I still own.

I ever so carefully updated the phone with a new RJ-30 jack (the original was bare wires), so that in a custom built base that the phone sits on is an Nvidia Jetson running an LLM and trained on Charlie Brown's voice and a voice recognition model.

Dialing 1 will answer questions about Snoopy and Peanuts history and Charles Schultz in Charlie Brown's voice. You can just talk to it. Dial 2 and a very nice lady with a British accent will read you a bedtime story, interactively, like a choose your own adventure of sorts, from a large database of stories. Dial 3 and Lucy will pick up, announce that the therapist is in, and talk with you about what's troubling you, again, voice recognition and an LLM. Dial 4 and you get Woodstock. Any other number gets you an "adult" from the Peanuts cartoon that is impossible to understand, again, voice recognition to understand what you're asking, but the response is unintelligible.

That's amazing!

I'm separately very interested in LLMs, but still very much in a "keep them the hell away from my kids" mindset.

Unfortunately I'm not terribly knowledgeable about the various AI revolutions that've been going on recently but this is the kind of project I'd love to try out doing! Would you ever consider doing a write-up? Or do you have any guides you'd recommend for getting started with this kind of thing?

OT, but for some reason the phrase "the various AI revolutions that've been going on recently" is incredibly amusing to me. To be clear, this is a compliment, not a criticism! There's something about referring to something implied to be incredible with such nonchalance that makes it sound like it sound like it comes from a sci-fi short story or something.

What a lovely project! Would you be willing to share your work? As with the project that kicked this off it would be great to see it even if it's just a jumble of scripts that would not work for anybody else.

Oh man, even a blogpost about the technical means of building this would be so delightful to read! Please share if you're able?

Very cool project. I was really struck by this comment:

> Dial out to a short list of family contacts. It's not something I think about much, but when I was a kid there was a phone on the wall and once I could reach it, I could use it. Now, if you're not old enough to have a cell phone, you also can't call anyone at all.

That's not something I've ever thought about, but is a really huge change in what kids can do. I was always allowed to call over to a friend's house and see if they could play.

I still have a landline. It comes from free with my fiber internet anyway, all I have to do is plug a phone.

That's really handy for kids.

I dropped mine when I dropped cable TV. It had more dependable quality than the cell at my house but, for the amount of calling I do, it wasn't worth the $40/month or whatever it was.

This is why I got a landline.

Another (weird) advantage of a landline: you didn't always know who was going to answer, sometimes you were just calling "the house," and it allowed for more serendipitous conversation.

The main example is probably just calling up your parents, whether as a kid or even as an adult calling up their elderly parents. Sometimes you just want to speak to "your parents." You didn't have to decide whether to call mom's cellphone or dad's cellphone. And you didn't have to worry about who you called last. Heck, with caller ID, mom or dad could even decide who wanted to chat with you.

My mother-in-law actually complains about this going the other way. Sometimes she just wants to call our house, because she'd love it if I randomly picked up and she could chat with me in passing. She'd find it awkward to call my phone, because we don't quite have that "chat about nothing on the phone" relationship, but it used to be that you could get two minutes of catching up with someone before you said "ok, now pass me to the person I was really calling for."

Can you get a burner phone as a "landline" that she can call?

Makes me wonder whether people lamented the end of party lines.

But I absolutely agree. Growing up, I occasionally had conversations with my parents’ friends when they’d call the house. I no longer have those.

Material scarcity creates community. Once we hit abundance, we have to find ways to add that back, I think.

Wow. I hadn't ever thought of it this way.

An acquaintance of mine ended up dating and ultimately marrying his friends sister. Their relationship started out of him calling “the house” to talk to his friend and the sister picking up and spending a few minutes talking with “your friend who has a nice voice”.

For my mother's 80th birthday I put a little computer in an old rotary phone.

I purchased a mobile phone number for a month with voicemail and set the voicemail to email me the messages.

I asked all her friends and family to call the number and leave a message saying something meaningful to mum and wishing her happy birthday.

I uploaded all the messages to an sd card and put the little computer in the phone and wired it up to the rotary dialer and wrote some python code which listened to the rotary dialer and played an mp3 on specific numbers.

Dialling a number played back a message from a friend/family member.

I later did the same thing for another family member but this time in an old radio and you could tune to different messages.

I got the idea from Caroline Buttet who has some really creative and interesting things on her channel, such as a peephole that shows random open security cameras and a world globe that plays local radio stations when you touch a country.

https://www.youtube.com/@carolinebuttet7095

That’s awesome. I love that it’s the intersection of tech and something so wholesome and unequivocally good. It feels hard to find in tech these days.

Nice project! Our house has something similar. Every room has its own rotary phone, with its own number (usually someone's birthday!). I think we have 7 or 8 total. They can't dial out or anything fancy like that, but they can all call each other. The kids mostly use it to call and ask us to bring snacks when they're playing, and we mostly use it to call them and ask them to come to dinner!

That's awesome.

How do you create the switchboard for this? Custom build or retrofit an intercom system?

With a VoIPBX I’d assume.

My son _loves_ the train status aspect and I'm happy to oblige as it gives me an excuse to hack, but as other people point out you can get a lot of mileage out of even just getting a landline. Or you could probably connect the Grandstream directly to Twilio or another low-cost VoIP provider for cheaper than a land line and keep the ability to limit which phone numbers can be used.

The project was delayed for a day for lack of a phone cable. (of all of the weird old cables I have somehow rj-11 is no longer one of them...) I considered buying one off Amazon but it felt incredibly wasteful, so instead I asked our IT department at work. Almost any office will have piles of these things sitting around collecting dust.

Nice, and the Grandstream adapter is good to know about. There is a gadget now called cell2jack that lets you use your old land phone as a mobile handset but going to VoIP is also interesting.

Quite a while ago, Sparkfin sold a rotary phone that had been modified to have a mobile phone board inside, but it is now long obsolete:

https://www.sparkfun.com/products/retired/287

I still have an old rotary phone around, with the carbon granule mic those things had. It sounds awful. Idk whether that's due to its age, or because those mics just sounded bad compared with modern condenser mics.

I have been thinking of getting a cell2jack to have a pseudo-landline at mom's, since there are people there who get confused by smart phones.

This board also looks promising:

https://www.keyestudio.com/products/keyestudio-raspberry-pi-...

Unfortunately GSM modules in that style no longer work because the 2g and 3g networks are now shut down around here.

That's great, I didn't know about those.

For anything that an adult depended on, especially if I didn't live with them, I'd prioritize simplicity and robustness over almost everything else.

Take that carbon mic element and tap it repeatedly on a hard surface to loosen up the granules of carbon that need to be able to move round in there when you speak into it. You may find that it improves the fidelity noticeably.

> my 4 year old son ... loves the subway, and is already pretty proficient at using a unix terminal to query the status of different trains

Regardless of everything else there, I found this amazing

ctrl-c was one of the first things I had to teach him :-)

He has a Pi with a 7" touchscreen and keyboard, with xterm and a notes app. Compared to other technology it seems to be fairly self-limiting.

If you ever get the opportunity to visit "this museum is (not) obsolete" in the UK it has an excellent room with a working analog phone exchange. You can dial rotary phones around the place and watch the switching machines come alive, see the tape loops play back system messages, etc etc its really cool. Plus its right next to the micro museum

> Instead we need some way to tell a new joke each time.

Simple. After presenting the caller with a joke, ask the caller to tell a joke of their own — without the punchline, press # when done. Record joke. Then tell caller to tell the punchline, press # when done. Record punchline.

No one would possibly abuse that, right?

I really want to link up a ships telegraph across the offices and kitchen to request/coordinate drinks as we're working from home separately. getting ahold of them are like a grand each, but much for a joke.

It depends on how much you're wiling to hack something together, but you can get new telegraph keys for like $30 apiece: https://www.aliexpress.us/item/3256805611852897.html

Connect those up to Raspberry Pis with audio jacks and you're off to the races.

Hell yes, I've been wanting to do this for years - maybe I'll finally pull the trigger and hook this up so my child can harass me telephonically after she's supposed to be in bed and asleep. :)

This is a cool project. It would be really powerful if you could integrate Home Assistant's voice assist into this. I haven't played with it much, but I believe you can create custom sentences which would probably help with the joke telling. Or I think you can even set ChatGPT as the backend which seems like it'd make some of this stuff a lot easier (like reformatting the train times). And this would enable speech to text so you wouldn't have to mess with a phone tree and mapping dialed numbers to letters.

This page lists 9 ATAs that support pulse dialing:

https://www.classicrotaryphones.com/forum/index.php?topic=20...

  - Minitar MVA11A
  - Grandstream HT502
  - Grandstream GXW-4008
  - Primus Lingo iAN-02EX
  - Innomedia MTA6328-2Re
  - Motorola VT-1005
  - Audio Codes MP-114 FXO
  - Digium IAXy s101i
  - Linksys RTP300 (maybe)

I like this, especially since I've hacked around with old phones myself in the past. However, one catch. Child entertainment based on vastly complex technology in the background becomes a maintenance liability when something intricate breaks but the child wants their toy to stay working right now. Ask me how I know...

Nice! I started a similar project with a rotary phone a couple years ago with asterisk (just to the point of making a test call). Wish I had heard about the Windstream device, I ended up getting a pulse to tone converter and a PAP2T to voipify it, but those seemed to work. If I decide to pick it back up again I will check out your scripts.

I wonder if one could build a bidirectional rotary dial, so that the higher digits don’t have to take so much time. ;)

This messes with the rotary tone timing, so you'd also have to convert it to generate the modern tones; and now you're getting really close to re-inventing push button phone :)

Wow, this is really cool, thanks for sharing. I've always liked the idea of a home phone, rather than personal phone, for all sorts of things that belong to the house and not me personally. This pushes it one step further, will definitely try it!

I straight out put RISC-V board into the retro-looking landline phone from ebay. Some soldering, a gpio-matrix keyboard (mine is a keypad and not a real pulse rotary) and baresip integration and it kinda works.

Fantastic project. I have an itch to turn a fax machine into a "facts machine" by pairing it with Alexa and programming it to only print out factual statements.

That's very nice.

--- You don't need an Asterisk server for basic things.

You can connect HT8xx directly to a VOIP provider.

Some VOIP providers like voip dot ms let you create extensions too.

Very cool and fun project! Thanks for sharing.

Now I wonder if any of the existing 4G gateways support pulse dialing.

if not, pulse to dtmf sounds like a reasonably-approachable (attiny?) side project?

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