ESP32 Adds New Features To 1990s Home Alarm System

Given how fast technology is progressing, some consumer gadgets lend themselves to being replaced every few years. Mobile phones are a particularly good example of a device that you probably won’t want to hold onto for more than 4 years or so, with TVs not far behind them. On the other hand, something like a home alarm system can stay in the fight for decades. As long as it still goes off when somebody tries to pop a window, what more do you need?

Well if you’re like [Brett Laniosh], you might want the ability to arm the system and check its current status from your phone. But instead of getting a whole new system, he decided to upgrade his circa 1993 Gardiner Gardtec 800 alarm with an ESP32. As it so happens, the original panel has an expansion connector which he was able to tap into without making any modifications to the alarm itself. If you’ve got a similar panel, you might even be able to use his source code and circuit schematics to perform your own modification.

Optocouplers link the ESP and alarm panel.

Now we know what you’re thinking. Surely there’s a risk involved when trusting an ESP32 connected to the Internet with the ability to disarm your home alarm system. [Brett] has considered this, and made sure that the web server running on the microcontroller can only be accessed from the local network. If he does want to connect from beyond WiFi range, he does so through a VPN. In other words, his code is never directly exposed to the wilds of the Internet and is always hiding behind some kind of encryption.

The WiFi connection allows [Brett] to arm and disarm the alarm system remotely, check if it’s been triggered, and reset it if necessary, all from his smartphone. But he’s also added in a 433 MHz receiver so he can use simple handheld fobs to arm the system if he doesn’t want to go through the phone. Even if you dropped out the Internet connectivity, this alone is a pretty nice upgrade.

For those not afraid to take the more invasive route, you could potentially reverse engineer and reprogram your old alarm panel. Or you could even so the full DIY route and create your own low-cost alarm system using the ESP32 and off-the-shelf modules.

Facing The Coronavirus

Some of us are oblivious to how often we touch our faces. The current finding is we reach for our eyes, nose, or mouth every three to four minutes. Twenty times per hour is an awful lot of poking, picking, itching, and prodding when we’re supposed to keep our hands away from glands that can transmit and receive disease. To curb this habit and enter the 2020 Hackaday Prize, [Lloyd lobo] built a proof-of-concept device that sounds the alarm when you reach for your face.

We see an Arduino Uno connected to the classic HC-SR04 ultrasonic distance sensor, an LED, and we have to assume a USB battery pack. [Lloyd] recommends the smaller Nano, we might reach for the postage-stamp models and swap the ultrasonic module out for the much smaller laser time of flight sensor. At its soul, this is an intruder alarm. Instead of keeping siblings out of your room, you will be keeping your hands out of the area below the bill of the hat where the sensor is mounted. If you regularly lift a coffee cup to your lips, it might chastise you, and if you chew sunflower seeds, you might establish a tempo. *crunch* *chip* *beep* *crunch* *chip* *beep*

We have reviewed technology to improve our habits like a bracelet that keeps a tally, and maybe there is a book that will help shirk some suboptimal behaviors.

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Break Time Is Calling On The Rainbow Connection

Like some of us, [Mister M] is prone to staying glued to his seat too long in this new era of working from home. And you know what they say about a body at desk — it tends to stay at desk until it absolutely must rise up to find food or use the restroom.

Thanks to this nifty new break time reminder, [Mister M] has a third call to answer that demands he get up. Every hour, the NeoPixel ring in this old dial-deficient phone fills up completely and switches over to an attention-getting rainbow animation. If [Mister M] stays seated, playtime is over. All the lights start flashing red, and the phone starts beeping incessantly until he walks across the room and either pushes the momentary button or lifts the handset to reset the timer.

We love that [Mister M] incorporated all of the phone’s original inputs and outputs into this project, because it’s such a cool old dog and bone. No need to drop a dime, just whistle at the break button to check out the build video.

This grille-faced phone was probably part of an intercom system. Incidentally, you can make an intercom system with two standard-style phones of this vintage.

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Build This Handy Leak Detector For $1.02

You’ve probably noticed that modern life has become rather complicated, and the projects we cover here on Hackaday have not been immune to the march of progress. We certainly aren’t complaining, but we’ll admit to the occasional wistful daydream of returning to the days when the front page of Hackaday looked more MacGyver than Microsoft.

Which is precisely why this hacked together water alarm from [dB] is so appealing. Dubbed the “SqueakyLeaks”, this gadget started its life as a simple wireless intruder alarm from the Dollar Tree. When the magnet got far enough from the battery-powered base, a 90 dB warble would kick in and let you know somebody had opened a window or a door they shouldn’t have.

But with a little rewiring and two Canadian pennies serving as contacts, the alarm has been converted to a water detector that can be placed around potential leaky appliances like the water heater or in areas where you want to be alerted to water accumulation such as sumps. They’re basically “set and forget”, as [dB] says the three LR44 batteries used in the alarms should last about two years. Though with a BOM of $1.02 CAD, it’s probably cheaper to just make multiples and throw them out when the batteries die. Continue reading “Build This Handy Leak Detector For $1.02”

See If Someone Has Been In Your Drawers With This Simple Alarm

There’s a spy movie – probably from the [James Bond] franchise – in which our hero is staying in a fancy hotel. It’s crawling with enemies, naturally, and eager to see if one has been snooping in his room while he’s out for martinis, he sticks a hair across the gap in the door. When he comes back and finds the hair missing, he knows the game is afoot.

This hotel safe intrusion detector is what [Q] might have thought up for such a job if he’d had access to PIC microcontrollers and SMD LEDs. [Andy]’s “LightSafer” is a silent alarm for hotel safes, drawers, closets, or even the refrigerator – anywhere where the transition from dark to light indicates an unwanted visit. It’s tiny – only 33 x 21 mm – and is powered by a CR2032 coin cell. A Broadcom APDS-9300 light sensor watches for openings while the PIC monitors a joystick control for the correct PIN entry. There’s no audible alarm; rather, an LED blinks to indicate an unauthorized intrusion and blinks once for every 15 minutes since the event.

LightSafer is simple but effective, with a clever UI that keeps the current draw low and the battery life long. [Andy] used a similar technique for this low-draw cat tracking collar that we featured a while back.

Alarm System Defeated By $2 Wireless Dongle, Nobody Surprised

It seems a bit unfair to pile on a product that has already been roundly criticized for its security vulnerabilities. But when that product is a device that is ostensibly deployed to keep one’s family and belongings safe, it’s plenty fair. And when that device is an alarm system that can be defeated by a two-dollar wireless remote, it’s practically a responsibility.

The item in question is the SimpliSafe alarm system, a fully wireless, install-it-yourself system available online and from various big-box retailers. We’ve covered the system’s deeply flawed security model before, whereby SDRs can be used to execute a low-effort replay attack. As simple as that exploit is, it looks positively elegant next to┬á[LockPickingLawyer]’s brute-force attack, which uses a $2 RF remote as a jammer for the 433-MHz wireless signal between sensors and the base unit.

With the remote in close proximity to the system, he demonstrates how easy it would be to open a door or window and enter a property guarded by SimpliSafe without leaving a trace. Yes, a little remote probably won’t jam the system from a distance, but a cheap programmable dual-band transceiver like those offered by Baofeng would certainly do the trick. Not being a licensed amateur operator, [LockPickingLawyer] didn’t test this, but we doubt thieves would have the respect for the law that an officer of the court does.

The bottom line with alarm systems is that you get what you pay for, or sadly, significantly less. Hats off to [LockPickingLawyer] for demonstrating this vulnerability, and for his many other lockpicking videos, which are well worth watching.

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Stove Alarm Keeps The Kitchen Safe

Gas cooktops have several benefits, being able to deliver heat near-instantly, while also being highly responsive when changing temperature. However, there are risks involved with both open flames and the potential of leaving the gas on with the burner unlit. After a couple of close calls, [Bob] developed a simple solution to this safety issue.

The round PCB sits neatly behind the knobs, affixed with double-sided tape.

Most commercial products in this space work by detecting the heat from the cooktop, however this does not help in the case of an unlit burner being left on. [Bob]’s solution was to develop a small round PCB that sits behind the oven knobs. Magnets are placed on the knobs, which hold a reed switch open when the knob is in the off position. When the knob is turned on, the reed switch closes, powering a small microcontroller which beeps at regular intervals to indicate the burner is on.

It’s a tidy solution to a common problem, which could help many people – especially the elderly or the forgetful. It integrates neatly into existing cooktops without requiring major modification, and [Bob] has made the plans available if you wish to roll your own.

On the other end of the scale, you might want an alarm on your freezer, too.