DIY ESP32 Video Doorbell Locks Out Big Brother

There’s no question that being able to see who’s at your front door from your computer or mobile device is convenient, which is why the market is currently flooded with video doorbells. Unfortunately, it’s not always clear who else has access to the images these devices capture. Organizations such as the Electronic Frontier Foundation have argued that by installing one of these Internet-connected cameras on their front door, consumers are unwittingly contributing to a mass surveillance system that could easily be turned against them.

Luckily, there’s a solution. As [Sebastian] shows in his latest project, you can build your own video doorbell that replicates the features of the commercial offerings while ensuring you’re the only one who has access to the data by leveraging open source, community developed projects such as ESPHome and Home Assistant. At the same time, modern manufacturing techniques like desktop 3D printing and low-cost PCB fabrication mean your DIY doorbell doesn’t have to look like you made it yourself.

The project starts with a custom PCB that combines the ESP32, a camera module, a capacitive touch sensor, a relay to optionally trigger an electronic door lock, and a DC-DC converter that will let you power the device from a wide range of input voltages. The board even has a spot where you can solder on an additional 8 MB of external PSRAM for the ESP32, which will enable the chip to capture higher resolution video.

The electronics are housed in a minimalistic 3D printed enclosure that would fit right in alongside similar gadgets from the likes of Ring and Arlo; especially if you have access to a CNC and can cut the front panel out of acrylic. The lighted touch sensor looks phenomenal, and really gives the device a professional feel. That said, it doesn’t look like the case would last very long if exposed to harsh weather and there are some obvious physical security issues with this approach. But to be fair, we’ve seen the same problem with commercial hardware.

Naturally with a project like this, the hardware is only half of the story. It takes a considerable amount of software poking and prodding to get things like mobile device notifications working, and as a special added annoyance, the process is different depending on which MegaCorp produced the OS your gadget is running. [Sebastian] has documented the bulk of the process in the video after the break, but the finer points will likely need some adjustment depending on how you want to set things up.

This is an exceptionally impressive project for sure, but if the whole slick futuristic look isn’t your style, you could always opt to go with the DIY video door bell that looks like it came from an alternate reality version of 1986.

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This Week In Security: BleedingTooth, Bad Neighbors, And Unpickable Locks

This week, the first details of BleedingTooth leaked onto Twitter, setting off a bit of a frenzy. The full details have yet to be released, but what we know is concerning enough. First off, BleedingTooth isn’t a single vulnerability, but is a set of at least 3 different CVEs (Shouldn’t that make it BleedingTeeth?). The worst vulnerability so far is CVE-2020-12351, which appears to be shown off in the video embedded after the break.

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Size Does Matter When It Comes To SD Cards

The SD card first burst onto the scene in 1999, with cards boasting storage capacities up to 64 MB hitting store shelves in the first quarter of 2000. Over the years, sizes slowly crept up as our thirst for more storage continued to grow. Fast forward to today, and the biggest microSD cards pack up to a whopping 1 TB into a package smaller than the average postage stamp.

However, getting to this point has required many subtle changes over the years. This can cause havoc for users trying to use the latest cards in older devices. To find out why, we need to take a look under the hood at how SD cards deal with storage capacity. Continue reading “Size Does Matter When It Comes To SD Cards”

Breathtaking Alarm Clock Looks Like It Came From A 1960 Fallout Shelter

All the hardcore geeks have alarm clocks where the bell striker is a hard disk read head… or at least they’ll be building them after seeing this. [Senile Data Systems] created an industrial voltage alarm clock out of decade counters that looks like it was unearthed from a fallout shelter (machine translation).

At first glace you might mistake this for a binary clock since it uses a column of LEDs to indicate each digit of 24-hour time. It’s not, as each row corresponds to a pin on the CD4017 decade counters that make up the timekeeping circuit inside.

Thumbscrew wheel switches at the top of the bulky handheld unit are how the alarm time is set, triggering a bell along the top edge. The clock is driven by the 50 Hz line voltage and [SDS] tried using that AC to drive a solenoid as the striker on the prototype unit but it performed poorly. The use of a hard disk read head turns out to be the perfect striker, as heard in the video after the break. As for triggering from the decade counters, here’s what [SDS] told us about the design:

The switches’ outputs gets ANDed with a 10 Hz signal (on a 60 Hz grid it will become 12 Hz). This drives a slightly beefy transistor which in turn drives an electromagnet to hammer a bell which broke off my bicycle. Yes. This is a digital analog alarm clock. The clock portion is digital but the bell is analog and sounds like Grampa’s old wind up alarm clock.

The build came about when a cache of over 600 industrial LEDs (24 V – 48 V) fell into his lap. This makes the insides of the clock something to behold as point-to-point soldering connects the panel mount lights and all nine logic chips. Add in that transformer for getting the line voltage and we imagine this thing has quite a bit of heft to it.

If you’ve ever had an alarm with a wind-up bell you know there’s no better way to jolt yourself out of a peaceful slumber and into the chaos of the real world. If the gentle tinkle of the hard drive head isn’t enough for you, this fire bell alarm clock will certainly do the trick.

 

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Hackaday Podcast 071: Measuring Micrometers, The Goldilocks Fit, Little Linear Motors, And 8-bit Games On ESP32

Hackaday editors Mike Szczys and Elliot Williams fan through a fantastic week of hacking. Most laser cutters try to go bigger, but there’s a minuscule one that shows off a raft of exotic components you’ll want in your bag of tricks. Speaking of tricks, this CNC scroll saw has kinematics the likes of which we’ve never seen before — worth a look just for the dance of polar v. Cartesian elements. We’ve been abusing printf() for decades, but it’s possible to run arbitrary operations just by calling this Turing-complete function. We wrap the week up with odes to low-cost laptops and precision measuring.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Lattice Semiconductor Targets Bitstream Reverse Engineering In Latest Propel SDK License

The topic of reverse engineering is highly contentious at best when it comes to software and hardware development. Ever since the configuration protocol (bitstream) for Lattice Semiconductor’s iCE40 FPGAs was published in 2015 through reverse engineering efforts, there has been a silent war between proponents of open bitstream protocols and FPGA manufacturers, with the Lattice ECP5’s bitstream format having been largely reverse-engineered at this point.

Update: About eight hours after this article was published, Lattice Semiconductor issued a statement retracting the EULA language that banned bitstream reverse engineering. Please check out Hackaday’s article about this reversal.

Most recently, it appears that Lattice has fired a fresh shot across the bow of the open source projects. A recently discovered addition to the Propel SDK, which contains tools to program and debug Lattice devices, specifically references bitstream reverse engineering. When logged in with an account on the company’s website the user must agree to the Lattice Propel License Agreement for Lattice Propel 1.0 prior to download. That document includes the following language:

In particular, no right is granted hereunder […] (3) for reverse engineering a bitstream format or other signaling protocol of any Lattice Semiconductor Corporation programmable logic device.

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ATMega328 SSB SDR For Ham Radio

The humble ATmega328 microcontroller, usually packaged as an Arduino Uno, is the gateway drug for millions of people into the world of electronics and embedded programming. Some people just can’t pass up the challenge of seeing how far they can push the old workhorse, and it looks like [Guido PE1NNZ] is one of those. He has managed to implement a software-defined SSB ham radio transceiver for the HF bands on the ATMega328, and it looks like the project is going places.

The radio started life as a QRP Labs QCX, a $49 single-band CW (morse code) HF transceiver kit that is already one of the cheapest ways to get on the HF bands. [Guido] reduced the part count of the radio by about 50%, implementing much of the signal processing digitally on the ATmega328. On the transmitter side, the SSB signal is generated by making slight frequency changes to a Si5351 clock generator using 800kbit/s I2C, and controlling a very efficient class-E RF power amplifier with PWM for about 5W of output power. The increased efficiency means that there is no need for the bulky heat sink usually seen on SSB radios. The radio is continuously tunable from 80m to 10m (3.5 Mhz – 30 Mhz), but it does require plugging in a different low pass filters for each band. Continue reading “ATMega328 SSB SDR For Ham Radio”