Pimped Out 70’s Home Intercom System, Now With More Pi

January 29, 2016 by 11 Comments

If you own a house that was built in the 1970’s, you might still have the remnants of a home intercom system on the walls of each room. They were consider the end-all-be-all of “home automation” back in the day. Now, they look dated and out of place (but still kind of retro-cool at the same time).  [Cpostier] decided that he wanted to keep his old intercom system, but give it an update with a Rasperry Pi and a 7 inch touch screen, and the results are totally groovy, man.

The original unit served two functions, as an intercom system, and also as a whole house music player.  [Cpostier] wasn’t interested in the intercom feature, and so he started with the traditional gutting of the 70’s dried up electronics. Each room received a new $7 speaker (from Amazon), and the main control panel was fitted with a Pi, TFT touch screen, and new amplifier. The Pi is running Kodi (formerly know as XBMC) and along with it being a great media player, it can also show weather data, or what ever else you would like.

Something magical happens when you blend new tech with old tech – we totally dig it.

Hacked Apartment Intercom Barks At You Or Buzzes You In

October 8, 2015 by 17 Comments

Forgot your apartment keys? If you’ve got a ritzy building with a doorman, no problem. If your digs are a little more modest, you might only have an intercom panel that calls up to your apartment so someone can buzz you in. But if nobody is home, you’re out of luck. That’s why [Paweł] spent an hour whipping up an intercom connected automation system pack full of goodies.

entryphoneThe design is pretty simple – an ATMega328P to snoop on the analog phone ringer in the apartment when the intercom call button is pushed, and a relay wired in parallel with the door switch to buzz him in. For added security, the microcontroller detects the pattern of button presses and prevents unwanted guests from accessing the lobby. Things got really fun when [Paweł] added a PCM audio module to play random audio clips through the intercom. As you can see in the video below, an incorrect code might result in a barking dog or a verbal put-down. But [Paweł] earns extra points for including the Super Mario Bros sound clip and for the mashup of the “Imperial March” with “The Girl from Ipanema”.

True, we’ve seen a slightly more polished but less [Mario] version of this project before, but the presentation of this particular hack has us grinning from ear to ear.

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Ask Hackaday: What To Do With A Home Intercom System?

January 19, 2013 by 103 Comments

[Kyle] just moved into a new home, a 1970s abode that was very modern for its time. When the house was built, a home intercom system was installed. Of course this intercom system was eventually disconnected, but now [Kyle] would like to find a use for it.

The intercom system is a wonderful piece of engineering from the late 60s and early 70s. The base station has an FM radio, a mono input (for plugging in a turntable, we suppose), and a huge speaker. The satellite units – one for each room in the house – are much simpler with just a push to talk switch and a volume control. Yes, in classic minimalist style, the engineers for this intercom system used the speaker as a microphone.

[Kyle] would like to keep the wonderful plastic fantastic aesthetic of the intercom system, but he’s looking for something cool to do with this hardware.  This could be the beginnings of a very cool, very strange house-wide artificial intelligence build, kind of like a consumer version of HAL 9000. We’re interested in hearing what you’d do with [Kyle]’s hardware, so leave your ideas in the comments.

Using Old Phones As An Intercom In Your VW Bus (or Anywhere Else)

June 8, 2012 by 68 Comments

In case you haven’t noticed from my many comments on the subject, I drive a VW bus. It is a 1976 Westfalia camper with sage green paint and green plaid upholstery. I absolutely love it and so does the rest of my family. We go for drives in the country as well as camping regularly. We have found that the kids have a hard time communicating with us while we’re going higher speeds. These things aren’t the quietest automobiles in the world. Pushing this bread loaf shaped hunk of steel down the road with an engine that might top out at 75hp results in wind noise, engine noise, and of course, vibration.

I decided to employ a really old hack to put two functional telephones in the bus so my kids can talk to my wife (or whoever the passenger is) without screaming quite so loud. This hack is extremely easy, fairly cheap, and can be done in just a few minutes. The result is a functional intercom that you could use pretty much anywhere!

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This Toy Intercom System Is Way Better Than A Pair Of Tin Cans And Some String

December 6, 2011 by 36 Comments

toy-intercom-system

On his blog, [Kenneth Finnegan] recently showed off a replica of a fun toy he used to play with as a kid, a telephone intercom system. The setup is pretty simple, requiring little more than a pair of analog phones, a battery, and a resistor.

The phones are connected to one another using a standard telephone cable, but [Kenneth] uses a 9v battery to introduce a small bias current into the loop, allowing the speakers at either end to hear one another. He also added a small LED into the circuit so that there is a visual indication as to when both handsets are off hook.

The setup is very simple at the moment, though [Kenneth] does have some ideas in mind to enhance his intercom system. He hopes to tweak the remote phone to ring when the local phone is picked up, among other things.

Telephone technology is nothing new, but for just a few dollars (or less) your kids can be entertained for hours as [Kenneth] was way back when.

Continue reading to see a short video overview of the phone system, and be sure to share your ideas for enhancing it in the comments section.

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Multi-Year Doorbell Project

September 17, 2023 by 4 Comments

Camera modules for the Raspberry Pi became available shortly after its release in the early ’10s. Since then there has been about a decade of projects eschewing traditional USB webcams in favor of this more affordable, versatile option. Despite the amount of time available there are still some hurdles to overcome, and [Esser50k] has some supporting software to drive a smart doorbell which helps to solve some of them.

One of the major obstacles to using the Pi camera module is that it can only be used by one process at a time. The PiChameleon software that [Esser50k] built is a clever workaround for this, which runs the camera as a service and allows for more flexibility in using the camera. He uses it in the latest iteration of a smart doorbell and intercom system, which uses a Pi Zero in the outdoor unit armed with motion detection to alert him to visitors, and another Raspberry Pi inside with a touch screen that serves as an interface for the whole system.

The entire build process over the past few years was rife with learning opportunities, including technical design problems as well as experiencing plenty of user errors that caused failures as well. Some extra features have been added to this that enhance the experience as well, such as automatically talking to strangers passing by. There are other unique ways of using machine learning on doorbells too, like this one that listens for a traditional doorbell sound and then alerts its user.

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Add A Little Quindar To Your Comms For That Apollo-Era Sound

April 30, 2023 by 9 Comments

If there’s one thing that ties together all the media coming out of the Apollo era, it’s probably the iconic Quindar tones. These quarter-second beeps served as control tones for the globe-spanning communications network needed to talk to the Apollo astronauts, and any attempt to recreate the Apollo-era sound would be glaringly wrong without them. And that’s why [CuriousMarc] whipped up this Quindar tone system.

The video below starts with a detailed treatment of what Quindar tones are and why they were used, a topic we’ve covered ourselves in the past. To recap, Quindar tones are a form of in-band signaling, with a 2,525-Hz pure sine wave intro tone that signaled the transmitters connected to Mission Control in Houston over leased telephone lines to key up. The 2,475-Hz outro tone turned off the transmitters and connected the line to the receivers.

To recreate the sound quality of the original circuitry, and to keep in the retro vibe, [Marc]’s Quindar homage avoided digital circuitry as much as possible, opting instead to generate the two tones with an XR-2206 function generator chip. The chip can rapidly switch back and forth between two frequencies, making it perfect for FSK applications or, in this case, reproducing the two slightly different tones. [Marc] added a dual mono-stable multi-vibrator to pulse the tone, giving the 250-ms pulse, and an audio gate, which uses a MOSFET to switch the tone into an audio stream. All this got soldered up to a piece of perf board and stuffed in the base of a cheap intercom microphone, which while not period accurate still has a cool retro look — and now, a retro sound, too.

Hats off to [CuriousMarc] and his merry band for probing the mysteries of Apollo-era comms and keeping the accomplishments of all those engineers alive. The methods they used are still relevant after all these years, and there seems to be no end to what we can learn from them.

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