Fixing (And Improving!) An Annoying Apartment Entry System

December 11, 2022 by Donald Papp 7 Comments

[Zak]’s two-floor apartment has a typical door entry control system, but the setup is less than ideally convenient. The wall-mounted telephone-like intercom is downstairs, but [Zak] is usually upstairs. What’s an enterprising hacker to do? Obviously the most elegant solution is to simply do without visitors in the first place, but [Zak] opted for a more full-featured solution to the problem.

The layout of the typical wall-mounted door intercom is less than ideal.

He fixed things with a custom ESP8285-based board that, with the help of opto-isolation, allows him to detect visitors and grant entry without having to be physically present at the wall-mounted intercom. It’s even integrated into Telegram, and has a few neat new features. Let’s take a look.

The first interesting bit is how [Zak] rolled his own opto-isolation. The door entry system uses 14 VAC and is frankly — electromagnetically-speaking — a very noisy device. Attaching GPIO pins directly to this system from the ESP board for interfacing is not an option. The solution in situations like this is to use opto-isolation, so that interfaced devices can be electrically isolated from one another.

Rather than use off-the-shelf options, [Zak] opted to keep things small and economical by rolling his own solution using side-mounted IR LEDs on the small interface PCB. LEDs can also act as photodiodes, so by pointing two LEDs directly at one another and driving one LED from the door control system and measuring the small amount of resulting current on the other LED, [Zak] can detect states without having to directly connect a GPIO pin.

Continue reading “Fixing (And Improving!) An Annoying Apartment Entry System” →

An Apartment-Hunting AI

October 7, 2019 by Inderpreet Singh 16 Comments

Finding a good apartment is a lot of work and includes searching websites for available places and then cross-referencing with a list of characteristics. This can take hours, days or even months but in a world where cars drive themselves, it is possible to use machine learning in your hunt.

[veesot] lives in a city between Europe and Asia and was looking for a new home, and his goal was to create a model that can use historical data to not only suggest if an advertised price was right, but also recommend waiting by predicting the decrease in the the future. The data-set includes parameters such as “area”, “district”, “number of balconies” etc and tried to determine an optimal property to view.

There is a lot that [veesot] describes in his post which includes cleaning the data in terms of removing flats that are tool small or tool large. This is essentially creating a training data-set for the machine learning system that will allow the system to generate usable output. [veesot] also added parameters such districts which relate to the geographical location, age of the building and even the materials used in the construction.

There is also an interesting bit about analyzing the data variables and determining cross-correlation which ultimately leads to the obvious conclusions that the central/older districts have older apartments and newer ones are larger. It makes for a few cool graphs but the code can certainly come in handy when dealing with similar data-sets. The last part of the writing discusses applying Linear Regression and then testing its accuracy. Interpreting the model produces interesting results about the trained model and the values of the coefficients.

Continue reading “An Apartment-Hunting AI” →

A Geek’s Revenge For Loud Neighbors

February 5, 2016 by Brian Benchoff 124 Comments

It seems [Kevin] has particularly bad luck with neighbors. His first apartment had upstairs neighbors who were apparently a dance troupe specializing in tap. His second apartment was a town house, which had a TV mounted on the opposite wall blaring American Idol with someone singing along very loudly. The people next to [Kevin]’s third apartment liked music, usually with a lot of bass, and frequently at seven in the morning. This happened every day until [Kevin] found a solution (Patreon, but only people who have adblock disabled may complain).

In a hangover-induced rage that began with thumping bass at 7AM on a Sunday, [Kevin] tore through his box of electronic scrap for every capacitor and inductor in his collection. An EMP was the only way to find any amount of peace in his life, and the electronics in his own apartment would be sacrificed for the greater good. In his fury, [Kevin] saw a Yaesu handheld radio sitting on his desk. Maybe, just maybe, if he pressed the transmit button on the right frequency, the speakers would click. The results turned out even better than expected.

With a car mount antenna pointed directly at the neighbor’s stereo, [Kevin] could transmit on a specific, obscure frequency and silence the speakers. How? At seven in the morning on a Sunday, you don’t ask questions. That’s a matter for when you tell everyone on the Internet.

Needless to say, using a radio to kill your neighbor’s electronics is illegal, and it might be a good idea for [Kevin] to take any references to this escapade off of the Internet. It would be an even better idea to not put his call sign online in the future.

That said, this is a wonderful tale of revenge. It’s not an uncommon occurrence, either. Wikihow, Yahoo Answers and Quora – the web pages ‘normies’ use for the questions troubling their soul – are sometimes unbelievably literate when it comes to unintentional electromagnetic interference, and some of the answers correctly point out grounding a stereo and putting a few ferrite beads on the speaker cables is the way to go. Getting this answer relies entirely on asking the right question, something I suspect 90% of the population is completely incapable of doing.

While [Kevin]’s tale is a grin-inducing two-minute read, You shouldn’t, under any circumstances, do anything like this. Polluting the airwaves is much worse than polluting your neighbor’s eardrums; one of them violates municipal noise codes and another is breaking federal law. It’s a good story, but don’t do it yourself.

Editor’s Note: Soon after publishing our article [Kevin] took down his post and sent us an email. He realized that what he had done wasn’t a good idea. People make mistakes and sometimes do things without thinking. But talking about why this was a bad idea is one way to help educate more people about responsible behavior. Knowing you shouldn’t do something even though you know how is one paving stone on the path to wisdom.
–Mike Szczys

Hacked Apartment Intercom Barks At You Or Buzzes You In

October 8, 2015 by Dan Maloney 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.

The 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.

Continue reading “Hacked Apartment Intercom Barks At You Or Buzzes You In” →

A Facelift For The View Out Your Livingroom Window

August 27, 2013 by Mike Szczys 22 Comments

livingroom-view-facelift

[Ken Kawamoto] turned the rather bland view from his livingroom into that of some high-priced real estate. It only works at night, which is going to seem odd since the image above shows a daytime scene. But it’s still a pretty sweet concept.

The video below shows the actual view from his window. We don’t think it’s all that bad (we once lived in a ground-level apartment looking out on a parking lot… yuck!). But the view of the Abbey of St. Étienne in Caen, France seen above is much better. He simply put a projector on his balcony and closed the light-colored blinds. So far he has to bring it in after each use, but we see this as more of a thing to use only when entertaining anyway.

We’ve seen a few other attempts over the years at hacking your view. Here’s one that adds fake windows using LCD screens. The thing that makes that one work is the ability of the system to track the viewer and change the perspective accordingly.

Continue reading “A Facelift For The View Out Your Livingroom Window” →

Key Code Door Lock Won’t Endanger Your Security Deposit

September 20, 2012 by Mike Szczys 13 Comments

College students have returned in droves to dorms and apartments at campuses everywhere. So this is the time of year we usually start seeing some coded entry hacks. [Charmonkey] recently took on the challenge at his new apartment. There were some caveats though. He needed to ensure the Landlord could still enter using a key, and he didn’t want to alter the door or the jamb in any way. What he came up with is a coded entry system that can turn the deadbolt.

In order to mount some hardware on the door he removed the inner part of the dead bolt assembly and used the pair of threaded tubes on the adjoining lock section as anchor points. This holds the Pokemon tin he’s using as a project box securely in place. The rest of the components all mount to it. These include the stepper motor that actuates the deadbolt, a switch for manual operation, an Arduino, and a motor driver board.

He got really creative with the keypad. The wires connecting it travel through the door’s peephole and into the smaller plastic project box that hosts the rest of the hardware.

[via Reddit]

Noise Pollution Tit For Tat Uses The Baha Boys As A Weapon

July 3, 2012 by Mike Szczys 88 Comments

Here [Matthew Br] explains the situation he’s in with the neighbors that share this wall of his apartment. When they listen to music they like it loud and so he gets to ‘enjoy’ the experience as well. But he can’t ignore it any longer, and has decided to use a sound volume detector to blast some tunes right back at them.

He taped a microphone to the wall and wired it up to his Arduino. It monitors incoming sound and, using an adjustable threshold, it will trigger when the neighbors are too loud. We think he was wise to include some time filtering that makes sure the loud noises are sustained and not just the result of someone bumping into the wall. When the system does detect loud music for a sustained period it triggers [Matthew’s] own CD player to pump out Who Let the Dogs Out? by the Baha Boys. It will play for a period of time, then shut off to listen and see if the neighbors are still rowdy.

He documents an actual run in the latter half of the clip after the break. We sure hope he’s living in a building with just two units, otherwise this will drive the rest of the neighbors batty as well!

Continue reading “Noise Pollution Tit For Tat Uses The Baha Boys As A Weapon” →