Vintage Car Phone Makes Real Phone Calls (Bluetooth Adapter Prototype)

My vintage car phone can make/accept real phone calls via Bluetooth! It's a work-in-progress, but here's a tour and demonstration of the early prototype.
I still need to do a ton of programming to "properly" handle various combinations of possibilities, but the basics are there.
I already have microphone audio connected up so I can talk into the car phone and the person on the other end of the call can hear me. I'll probably work on temporarily wiring up incoming audio to the handset (disconnect my current sound input from the microcontroller) just to work out details of audio configuration on the Bluetooth module, and whatever else I may need to do to get the audio to the right level.
My next major problem to solve is how to programmatically switch between audio sources. I will need to switch between the microcontroller and the Bluetooth module as the source of the sound going to the handset, and I'll also eventually need to switch between the handset microphone and an external "hands free" microphone for outgoing audio to the Bluetooth module.
Full details of my project are documented here: www.electro-te...
The car phone is a DiamondTel Model 92.
The microcontroller is a Microchip PIC18F27Q43.
The Bluetooth module is a Microchip BM62.
See this KZbin playlist for more videos about this car phone project: • Satisfying: Peeling Fi...

[@joseguillen3340]

If you make one of those solder yourself kits of this, you bet your butt I'll buy two

[@waylonfinlay4927]

Oh MY GOD I will pay you hundreds to make me one. Dude you're a genius.

[@UselessPickles]

If you have a DiamondTel Model 92 phone, then that should be possible soon. I’m testing a new version now with custom PCBs that fit inside of the original phone.

[@UselessPickles]

kzbin.info/www/bejne/q3bXp6Cfn9Gri6csi=a0vtz-iO7V4R5MFa

[@waylonfinlay4927]

@@UselessPickles thank you for replying! That sounds so insane! Offer still stands haha

[@mh3982]

Dude this is dope. Please keep us updated i'd love to use something like this for my old car phones! Possibly put them in my cars!

[@UselessPickles]

Update: I have a "finished" project, and I published all the technical details and source code on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth

[@munnsie100]

Wow, I’d love to make one of these for a carphone and set it up for my own period correct cars!

[@UselessPickles]

I published everything (free for personal use), so you could build one if you have the skills and patience to do so: github.com/UselessPickles/diamondtel-m92-bluetooth But it only works for a couple models of Mitsubishi/DiamondTel phones. To make it work with any other phone, you'd have to reverse-engineer that phone and design custom hardware and software specific to that phone.

[@theflipphonechannel8198]

This is amazing! I'd love to have something like this!

[@UselessPickles]

If you are skilled/determined enough, you can make your own Bluetooth adapter for this phone. I published all the technical details and source code on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth

[@theflipphonechannel8198]

@UselessPickles Awesome! My car (Infiniti Q45) also had the option for a factory car phone so I will definitely be doing this someday. It's just a matter of finding the Infiniti branded car phone...

[@miniondave6314]

I really want to give this a try. It's a good excuse to learn how to program microcontrollers.

[@tohmestreetz]

This is amazing! Please keep us updated with more of this content!!!!

[@UselessPickles]

I've posted a few more videos since this one, but progress has slowed down a lot now. I'm spending a lot of time fixing problems with the electronics (sound quality and noise/interference issues), fixing bugs in the software, and adding minor features that aren't really worthy of a video. I think my next major milestone will be transferring the entire circuit to a soldered prototype board, after I've worked out the issues with the circuit.

[@samwellfoden]

I came across this project on Google images. So glad I’ve found a video thanks man. Amazing work

[@UselessPickles]

Thanks! Be sure to check the description for links to a forum thread with progress/details, and a link to a youtube playlist of other videos of this project :)

[@N01Dad]

Incredible. I hope to see the final product. Thank you.

[@UselessPickles]

Here it is: kzbin.info/www/bejne/a2OkppuJaq-kZrM It's still a custom prototype. But it's probably as "final" as it will ever get. All the technical details and source code are published on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth

[@423tech]

So thrilled to see this!

[@pushtoyota]

That is awesome!

[@FG-lq4pz]

Wow - this is absolutely amazing.

[@UselessPickles]

Thanks! Check out my video of the completed project, installed in my car, complete with integrated hands-free conversation and voice dialing/commands: kzbin.info/www/bejne/a2OkppuJaq-kZrM

[@alejandrosala2989]

Genius!!!

[@UselessPickles]

Thanks! This is a pretty old and incomplete version of this project. Check out how far I've come with it now! kzbin.info/www/bejne/q3bXp6Cfn9Gri6c

[@arbutuswatcher]

I've never heard of Diamond Tel. Are they the maker of the phone? It closely resembles an OKI Telecom cellphone. When you get this project completed, I would be very interested in the final product. This could breath new life, into some of the older analog cellphones. Finally, a decent sounding speaker! :)

[@UselessPickles]

Mitsubishi is the manufacturer. DiamondTel is a "premium" brand name that Mitsubishi used for some of their phones. This phone is functionally (but not physically) nearly identical to the Mitsubishi Model 1500 phone (handsets and transceivers are cross-compatible). Unfortunately, my solution is very specific to the communications between the transceiver and handset for these models of phone. It may possibly work for some other DiamondTel/Mitsubishi phones, but I'd be very surprised if it worked for any other brands of phones, because the communication between the transceiver and handset is most likely proprietary. I also don't know if I'll ever get this past the point of being a rough prototype just barely good enough for my personal use, but I will eventually be publishing technical details, circuit diagrams, and source code.

[@georgeh210]

Great Job!!

[@ww21943]

Love this! The sounds are what do it for me

[@UselessPickles]

Thanks! I put some effort into identifying exact frequencies and timing of all the sounds that the original phone made so that I could replicate it. (edit: I now realize you already know this; we already discussed it in comments of another video)

[@ww21943]

@@UselessPickles I forgot about it and then found the original video I commented on! I guess you took down your IG page since then.

[@UselessPickles]

@@ww21943 I’m still on Instagram: uselesspickes

[@ww21943]

@@UselessPickles Just tried again from my phone and computer. "No results found"

[@ww21943]

@@UselessPickles Scratch that, found it. Missing the L

[@blackhawkeyesti3596]

I loveeee this ideaaaa have you gotten a finished product? I would love to get an old bmw or old Mercedes and make the car phone work

[@UselessPickles]

I have a "finished enough for my personal use" prototype. Here's a full tour/demo of it in the car, complete with OEM hands-free integration and voice command support: kzbin.info/www/bejne/a2OkppuJaq-kZrM Full technical details on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth Unfortunately, this solution is very specific to the DiamondTel Model 92 car phone. Different custom hardware and software would be needed for any other models of car phone, after reverse-engineering how it works.

[@frankwhite2072]

Wow this is cool.

[@AugustusTitus]

awesome

[@Ozzy19907]

I’d love to put a 90’s car phone in my 95 300zx twin turbo!

[@Gen-X-Rising]

Take my money please , I need this for my set up

[@UselessPickles]

I will gladly take your money. I just don't have anything to give you in return :) It's still just a sloppy breadboard prototype velcroed to the carpet in my trunk, with digital noise interference issues on the audio and some bugs due to rushed sloppy code.

[@Gen-X-Rising]

@@UselessPickles well let's hurry it up then.I got money to spend.

[@smoothsailing6132]

Awesome would love to put one in my old school

[@chadgaspard]

I'd love to install one of these kits into my truck! Do you sell the completed plug and play PCBs?

[@UselessPickles]

I have not developed this beyond a hand-crafted prototype (no PCB), and I currently have no plans to do so. I published all the technical details, configuration files, and source code, free for personal use: github.com/UselessPickles/diamondtel-m92-bluetooth You could build one for yourself if you have the necessary skills and patience. But this only works with a couple specific models of Mitsubishi-manufactured phones.

[@andresmorales2863]

Wow amazing, i have been looking for something like this for quite some time....i hope you keep your hard work. P.D could it work using a Motorola cara phone?

[@UselessPickles]

Thanks! This is one of my older videos of this project. Check out this playlist of all videos related to this project, including a complete tour/demo of it completed and fully working in my car with hands-free integration: kzbin.info/aero/PLOlio4FadqvQEWHDXaJHlkvHigROk-RNV Unfortunately, my project is very specific to this DiamondTel Model 92 car phone. A similar approach would probably work for a Motorola car phone, but would require reverse engineering that particular model of phone and developing different custom hardware and software. If you're curious about the technical details, I published all of the reverse-engineered info about the car phone, circuit design, and microcontroller source code on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth Or you can read through this forum thread where I documented my progress on the project: www.electro-tech-online.com/threads/making-a-bluetooth-adapter-for-a-car-phone-from-the-90s.162764/

[@rutrowmedia]

You need to go into business selling this

[@retrogaminggenesis6102]

You should make a KickStarter or something. I'd buy one!

[@UselessPickles]

The market for this device would be quite limited. There's only 2 specific models of Mitsubishi/DiamondTel phone that it is known to be compatible with, and it is unlikely to be compatible with many more. I don't think it would be worth the investment to pay proper professionals to design consumer-quality hardware. But I do plan to work on publishing everything as an open source project (free for personal use). It should be enough information for any tech-savvy person with soldering skills to replicate what I've done.

[@ChrisRogersBrisbane]

@@UselessPickles I was in the process of reverse engineering the GM motorola system when I found this. Oldsmobile trofeo had all this integrated into the screen. so the screen is a second handset more or less. looking at what you have done , I understand it, worked out in the first couple of videos where you mapped the handset commands and so on/ great idea and I love it!

[@UselessPickles]

@@ChrisRogersBrisbane Welcome to the very small club of car phone reverse-engineering! When I started working on my project, I couldn't find any examples of anyone that had done anything similar at all. The closest I found was a couple examples of people that gutted the handset of a car phone and hacked an off-the-shelf Bluetooth headset into it. In case you haven't seen it yet, here's a forum thread where I documented many of the technical details of how I reverse-engineered the car phone and developed the Bluetooth adapter: www.electro-tech-online.com/threads/making-a-bluetooth-adapter-for-a-car-phone-from-the-90s.162764/ And here's the GitHub repo where I published all of the technical info, circuit design, and source code: github.com/UselessPickles/diamondtel-m92-bluetooth Hopefully this gives you some more ideas about how to tackle your project :) Will you be posting any info/updates about your project anywhere? I'd be interested to see what you do.

[@tomaskovacik]

nice!

[@UselessPickles]

It wouldn't have been possible without your breadboard adapter, so thank you! I'm not quite ready to get into designing PCBs, but I suspect I'll be more motivated to learn after I get this prototype more finalized. First, I will probably upgrade from breadboards to a perforated prototype board after my circuit is more finalized.

[@tomaskovacik]

@@UselessPickles that adapter is not designed to by used in final circuit, traces for audio are not properly spaced and routed etc.... lot of notice is picked on the way, so new and better board is probably good idea :)

[@UselessPickles]

​@@tomaskovacik Good to know. Now I can blame your board for my excess noise, even though my circuit is very sloppy and likely introducing substantially more noise :) I have never designed a PCB before, and only know some of the very basic hypothetical concepts about routing traces "properly". I'm still working with breadboards. I have a few more problems to solve before I move everything to a generic through-hole prototype board. I'll still be using your board to adapt to the through-hole board, but I hope the soldered connections and better ground routing will substantially reduce noise caused by my sloppy breadboard circuit. I don't know if I will ever advance from the prototype board to a PCB. For a one-time custom personal project, I think I may be happy enough with the prototype board.

[@harryvandoorn7471]

@@UselessPickles i can design a pcb for you if you have (sketches) of the schematic diagram

[@UselessPickles]

@@harryvandoorn7471 Thanks for the offer! I will get in touch if/when I think I may be ready to do this.

[@theweirdospfan.28]

I want this so bad lmao

[@bmarcum1570]

Do you have an official schematic? I'm incredibly interested in duplicating this.

[@UselessPickles]

I don't have a complete circuit diagram yet, but I do have a diagram of all the major components involved, and the major connections between them. You can find it in the README of the "hardware" directory of my github project: github.com/UselessPickles/diamondtel-m92-bluetooth Source code is still a big sloppy mess that I'm slowly cleaning up (and getting distracted introducing new/updated functionality) and I still need to figure out how I'm integrating with the radio and hands-free controls in the car (hardware + software updates). I also still need to figure out what licensing to apply to this project. It technically defaults to being fully copyrighted (no one can use it for anything without my express permission), but the eventual intent will be that it is free to use/modify for any personal/educational non-profit purposes.

[@Fernando-Garcia0685]

😱wow bro I was wondering how could make an Obsolete BMW phone ☎️, to install it on a Obsolete Police BMW motorcycle 🏍️ and I got higher hopes. Thank you 😃✌🏻🏍️

[@ThatDaltonGuyW]

I need one!!!

[@UselessPickles]

If you are skilled/determined enough, you can make your own Bluetooth adapter for this phone. I published all the technical details and source code on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth

[@SplittingVoices]

Sweet !

[@creativephotographer]

Is it possible to switch the guts out of the nrains and slide in a 5G card since nothing is in the headset containing this? Definitely amazed with your progress!

[@UselessPickles]

That sounds much more complicated than what I did :). When swapping guts of another phone into the handset of the car phone, you would have to solve problems like integrating the car phone handset buttons with the guts of the newer phone, and fitting the display of the modern phone into the handset of the car phone (plus more problems). The end result would also be much different. The behavior and display of the phone would be that of a more modern phone, but inside the physical case of the old car phone handset. My approach preserves the authentic behavior/experience of using the original car phone. Check out my newer videos. I've made much more progress since this video :).

[@rutrowmedia]

I want one

[@c.rincon7145]

I need this for my 1994 BMW 850CSi with BMW phone.

[@UselessPickles]

Unfortunately, this only works with the DiamondTel Model 92 phone. Different custom hardware and software would need to be developed for your model of phone, but the same general approach could be used. More details: github.com/UselessPickles/diamondtel-m92-bluetooth

[@c.rincon7145]

Your amazing with the tech. Unfortunately, I would need a electrician to figure this out, as I sure couldn't. Will need to flesh out my sources for help on this adaptation.

[@UselessPickles]

@@c.rincon7145 An electrician won't be able to help you with this. You need a hardware engineer and a software engineer. Preferably one person that can do both.

[@ChrisRogersBrisbane]

exactly.

[@nicolah]

Amazing job congrats

[@bmarcum1570]

Looks like there's an equivalent unit actually sold on Amazon called cell2jack

[@UselessPickles]

Cell2jack is only vaguely similar in that it adapts "a phone" to make/receive calls via Bluetooth through a cell phone. However, that product only works with landline phones. It would not work with a car phone handset, because a car phone handset is not a landline phone. The car phone handset isn't even really a phone of any kind at all. It is merely a dumb input/output device with buttons, a screen, speakers, and a microphone. The "brains" of the car phone are all in the transceiver/base that the handset plugs into.

[@Tylerm.944]

Could I pay you to do this to my Motorola bag phone? Looking to get actual usage out of it so I can put it in my 1987 Porsche 944. Not much of a tech guy myself so I have no clue what to do

[@UselessPickles]

Unfortunately, my project will only work with this particular model of phone. I have no plans to try building adapters for any other models of phones because it would be too much work (I've been working on this one for over a year in my free time and I'm not done yet), and there's a chance I could even fail at reverse-engineering how the handset of another phone model works.

[@rustys1242]

Can you please start selling these I would be happy to buy one or just list the parts / schematic and I will build it.

[@UselessPickles]

I won't be selling any, but I published everything on GitHub already: github.com/UselessPickles/diamondtel-m92-bluetooth

[@johnnycage9914]

I made my car phone a few years ago

[@UselessPickles]

How did you make a car phone?

[@Second.Q]

Is’t possible to play music from the iPhone through such connection with the car phone all ahead to vehicle stereo speakers? Can it be done?

[@UselessPickles]

Not in my 3000GT, because the car phone system is only connected to the front right speaker. When the phone is "in use", the radio is automatically muted and the car phone system takes over the front right speaker. But the stock radio in my 3000GT has an AUX input jack, so I simply connect my phone with an audio cord for music. And I can use voice commands through the car phone system's microphone to control the music on my phone :) You can see this all in action in this video: kzbin.info/www/bejne/a2OkppuJaq-kZrM

[@Second.Q]

@@UselessPickles Bro… I think you should invest your talent! what would you say if I passing the technical sticker chart for my bmw e32 phone modules and the phone himself. Would you be interesting to break down the system and return back to me with consideration and the diagrams so I can run it in the way that I mentioned before in the earlier comment?

[@UselessPickles]

@@Second.Q Sorry, but I'm an amateur at this electronics stuff. I've been working on this project for over 2 years now as a personal project purely for my own enjoyment. I have very little confidence that I could take on a project of reverse-engineering a different phone and designing new hardware/software for it, etc., within any reasonable amount of time. It would likely take me hundreds of hours of my free time, and I value my time, so it would end up costing you 10's of thousands of dollars to compensate me for my time that I'd rather spend doing something I want to do.

[@walkeranderson7860]

How much would I have to pay you for you to make me the same thing? I had one that worked in are old work van but the service got discontinued in 2015

[@UselessPickles]

I haven't even finished making one for myself yet (it's still a sloppy breadboard prototype), and I'm not sure I trust my amateur electronics knowledge and assembly skills enough to feel comfortable selling any. I can't really make any guarantees about longevity/safety, or offer any support. But I am going to work on publishing all the technical details of this project over the next few months. NOTE: If your phone is not a DiamondTel Model 92 or Mitsubishi Model 1500, then this would not work for you.

[@joserodriguezjr3515]

I need one.

[@UselessPickles]

If you are skilled/determined enough, you can make your own Bluetooth adapter for this phone. I published all the technical details and source code on GitHub: github.com/UselessPickles/diamondtel-m92-bluetooth

[@JohnMitchellCPA]

I have one, do you offer this converting service? Locate in SC but could ship it to you.

[@UselessPickles]

No I do not. Also, it's not a conversion/modification of the phone. It's an external adapter that is plug-n-play. I published all the technical details, microcontroller source code, Bluetooth module configuration, etc., on github: github.com/UselessPickles/diamondtel-m92-bluetooth

[@JohnMitchellCPA]

@@UselessPickles CAN YOU SHARE THE LINK TO BUY THE EXTERNAL ADAPTER? I don't see it listed on github.

[@UselessPickles]

@@JohnMitchellCPA You cannot purchase the adapter. I only built one for myself. If you want one, you need to build your own using all the information I published: github.com/UselessPickles/diamondtel-m92-bluetooth#build-your-own-bluetooth-adapter

[@jamesgreen1337]

How much to do one for me i have old car phones

[@UselessPickles]

If you have a DiamondTel Model 92 or Mitsubishi Model 1500, then I may be able to sell a kit sometime soon-ish (next 6 months or so). I'm working on a new version of my project that installs inside of the original phone's transceiver, replacing the original circuit board, and using custom PCB that will make assembly time more reasonable than my current prototype. Price TBD after I figure out total parts cost and assembly time. If you have a different car phone model, then my project will not work for you. I may consider developing a Bluetooth adapter for another model of car phone if either: 1) I have a personal desire to have another model of car phone that is fully functional (unlikely) 2) I win the lotto or otherwise become so wealthy that I can retire early and work on new car phone projects for fun as my new "full-time job" (unlikely) 3) You are willing to pay obscene amounts of money that convince me to give up a year of my free time to reverse engineer another phone and develop all new hardware and software to work with that phone, while accepting the risk that I may fail to complete a functioning product because I'm an amateur at electronics (unlikely)

[@ahmadrishi757]

Can you please start production

[@UselessPickles]

Maybe soon. I have a new design that I can reproduce more easily: kzbin.info/www/bejne/q3bXp6Cfn9Gri6csi=D3h0nlmFuE_g62tt I need to test and refine some more, then figure out effort and cost to make them in small batches. It will be a conversion kit or service. You will need to provide your own DiamondTel Model 92 car phone.

[@JoshuaFailing]

I will do this with a dynatac

[@JoshuaFailing]

Either this or reactivate 1g

[@UselessPickles]

I think that reactivating 1G may be practically impossible. No cellular service provider will ever do this because it is outdated insecure and inefficient technology, and the frequency bandwidth for 1G has been reallocated for other purposes now. You'd have to create your own private 1G base station (violating various laws about radio frequency use) that adapts to modern cellular networks, either using Bluetooth HFP like I did, or more directly with a cellular module and sim card.

[@coffeeexpert7023]

I need to bay this from you

[@UselessPickles]

I don't think I'll be making any of these for sale. I recently finished building a more sturdy prototype for myself, and it took 2 full weekends of my free time. You can make one for yourself, though. All the info and source code is here: github.com/UselessPickles/diamondtel-m92-bluetooth

[@Seniorsauvage]

So what happens when you don’t have cell service on the modern phone?

[@UselessPickles]

Depends on the exact time of when the phone list service vs when you try to make the call. If service has been lost long enough for the cell phone to report lack of service over Bluetooth, then if you try to make a call I simulate exactly how the original car phone behaved without service. The "in use" indicator comes on and it plays a really annoying "call failed" sound. If the lack of service has not yet been communicated over Bluetooth, then my adapter will try to send the call over Bluetooth, the car phone will behave as if it's beginning to make a call, but then the call will fail on the modern cell phone and end, and the car phone will act like the person on the other end rejected the call (call will simply end). This video shows some examples of the service status being synchronized from the cell phone to the car phone: kzbin.info/www/bejne/kJyxo4tsndx-hq8 And this video includes an example of me trying to make a call on the original car phone without service: kzbin.info/www/bejne/a2OkppuJaq-kZrM