Low-Power Wi-Fi Includes E-Paper Display

March 10, 2023 by Bryan Cockfield 6 Comments

Designing devices that can operate in remote environments on battery power is often challenging, especially if the devices need to last a long time between charges or battery swaps. Thankfully there are some things available that make these tasks a little easier, such as e-ink or e-paper displays which only use power when making changes to the display. That doesn’t solve all of the challenges of low-power devices, but [Albertas] shows us a few other tricks with this development board.

The platform is designed around an e-paper display and is meant to be used in places where something like sensor data needs to not only be collected, but also displayed. It also uses the ESP32C3 microcontroller as a platform which is well-known for its low power capabilities, and additionally has an on-board temperature and humidity sensor. With Bluetooth included as well, the tiny device can connect to plenty of wireless networks while consuming a remarkably low 34 µA in standby.

With a platform like this that can use extremely low power when not taking measurements, a battery charge can last a surprisingly long time. And, since it is based on common components, adding even a slightly larger battery would not be too difficult and could greatly extend this capability as well. But, we have seen similar builds running on nothing more than a coin cell, so doing so might only be necessary in the most extreme of situations.

A Mega-Tiny Arduino

March 2, 2023 by Bryan Cockfield 26 Comments

Integrated circuits, chipsets, memory modules, and all kinds of other transistor-based technology continues to get smaller, cheaper, and more energy efficient as time moves on. Not only are the components themselves smaller, but their supporting infrastructure is as well. Computers like the Raspberry Pi are about the size of a credit card and have computing power on the order of full-sized PCs from a few decades ago. The Arduino is no exception to this trend, either, and this new dev board called the Epi 32U4 might be the smallest ATmega platform we’ve seen so far.

As the name suggests, the board is based around the ATmega32U4 which is somewhat unique among Atmel chips in that it includes support for USB within the chip itself rather than relying on external translating circuitry. This makes it an excellent choice for any project which involves sending keyboard, mouse, or other peripheral information to a computer. This goes a few steps further with eliminating “bloat” compared to other boards, too — there’s no on-board voltage regulator, and just a single LEDs on pin 13.

One of the other features this board boasts over other small form factor boards is on-board USB-C, which is definitely a perk as more and more devices switch away from the various forms of older USB-type plugs. The project’s specifications are also available on this GitHub page for anyone that wants to produce their own. And, if you don’t have a 32U4 on hand and still want to build a keyboard project, it’s possible to get some other Arduinos to support these features but it’ll take a little more work.

Thanks to [Rasmus L] for the tip!

Security Vulnerabilities In Modern Cars Somehow Not Surprising

March 2, 2023 by Bryan Cockfield 16 Comments

As the saying goes, there’s no lock that can’t be picked, much like there’s no networked computer that can’t be accessed. It’s usually a continual arms race between attackers and defenders — but for some modern passenger vehicles, which are essentially highly mobile computers now, the defenders seem to be asleep at the wheel. The computing systems that control these cars can be relatively easy to break into thanks to manufacturers’ insistence on using wireless technology to unlock or activate them.

This particular vulnerability involves the use of a piece of software called gattacker which exploits vulnerabilities in Bluetooth Low Energy (BLE), a common protocol not only for IoT devices but also to interface a driver’s smartphone or other wireless key with the vehicle’s security system. By using a man-in-the-middle attack the protocol between the phone and the car can be duplicated and the doors unlocked. Not only that, but this can be done without being physically close to the car as long as a network of some sort is available.

[Kevin2600] successfully performed these attacks on a Tesla Model 3 and a few other vehicles using the seven-year-old gattacker software and methods first discovered by security researcher [Martin Herfurt]. Some other vehicles seem to have patched these vulnerabilities as well, and [Kevin2600] didn’t have universal success with every vehicle, but it does remind us of some other vehicle-based attacks we’ve seen before.

Morse Code Clock For Training Hams

March 1, 2023 by Bryan Cockfield 13 Comments

It might seem antiquated, but Morse code still has a number of advantages compared to other modes of communication, especially over radio waves. It’s low bandwidth compared to voice or even text, and can be discerned against background noise even at extremely low signal strengths. Not every regulatory agency requires amateur operators to learn Morse any more, but for those that do it can be a challenge, so [Cristiano Monteiro] built this clock to help get some practice.

The project is based around his favorite microcontroller, the PIC16F1827, and uses a DS1307 to keep track of time. A single RGB LED at the top of the project enclosure flashes the codes for hours in blue and minutes in red at the beginning of every minute, and in between flashes green for each second.

Another design goal of this build was to have it operate with as little power as possible, so with a TP4056 control board, single lithium 18650 battery, and some code optimization, [Cristiano] believes he can get around 60 days of operation between charges.

For a project to help an aspiring radio operator learn Morse, a simple build like this can go a long way. For anyone else looking to build something similar we’d note that the DS1307 has a tendency to drift fairly quickly, and something like a DS3231 or even this similar Morse code clock which uses NTP would go a long way to keeping more accurate time.

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Pokemon ROM Hacks Brought To The Real World

February 27, 2023 by Bryan Cockfield 4 Comments

If you were a kid anywhere in the last 30 years, it was nearly impossible to avoid at least some exposure to the Pokemon franchise. Whether that’s through games like Red and Blue to Scarlet and Violet, the brief summer everyone played Pokemon Go, or to other media such as the trading card game or anime, it seems to have transcended generations and cultures fairly thoroughly. And, if you’ve consumed all there is of official Pokemon video gaming, you may be surprised to know there are a number of slightly modified games floating around out there that can be translated onto game carts just like their official counterparts.

[imablisy] has played a lot of these ROM hack games but always within something like a virtual console or emulator, so he wanted something physical which would work on original hardware of the era. For this he’s making physical copies of Flora Sky and Vega, which are based on Pokemon Emerald and Fire Red originally for the Game Boy Advance. To get the cart he found a bunch of Mother 3 cartridges to use as the donor. From there he backed up his Emerald and Fire Red cartridges, modified the ROMs with the modifications, and then sent those new ROMs to overwrite the data on the Mother 3 cartridges.

A playable cartridge is only half of the build, though. He wants these to look and feel like real Pokemon games, so he added a color-appropriate translucent case and also printed custom holographic labels for each. It might seem straightforward, but from the style of [imablisy]’s video it’s clear he is very familiar with processes like these, from the artwork all the way to the hardware and software side. We’re also pleased no classic hardware was damaged during this build, much like this version of Doom on an NES cart which used a common game for the donor to upset the least number of collectors.

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Antenna Hidden In Holiday Lights Skirts HOA Rules

February 27, 2023 by Bryan Cockfield 90 Comments

For all their supposed benefits, homeowner’s associations (HOAs) have a reputation of quickly turning otherwise quaint neighborhoods into a sort of Stanford prison experiment, as those who get even the slightest amount of power often abuse it. Arbitrary rules and enforcement abound about house color, landscaping, parking, and if you’ve ever operated a radio, antennas. While the FCC (at least as far as the US is concerned) does say that HOAs aren’t permitted to restrict the use of antennas, if you don’t want to get on anyone’s bad side you’ll want to put up an antenna like this one which is disguised as a set of HOA-friendly holiday lights.

For this build, a long wire is hidden along with a strand of otherwise plain-looking lights. While this might seem straightforward at first, there are a few things that need to be changed on the lighting string in order to make both the antenna and the disguise work. First, the leads on each bulb were removed to to prevent any coupling from the antenna into the lighting string. Clipping the leads turns what is essentially a long wire that might resonate with the antenna’s frequency into many short sections of wire which won’t have this problem. This also solves the problem of accidentally illuminating any bulbs when transmitting, as the RF energy from the antenna could otherwise transfer into the lighting string and draw attention from the aforementioned HOA.

Tests of this antenna seemed to show surprising promise while it was on the ground, but when the string and antenna was attached to the roof fascia the performance dropped slightly, presumably because of either the metal drip edge or the gutters. Still, the antenna’s creator [Bob] aka [HOA Ham] had excellent success with this, making clear contacts with other ham radio operators hundreds of miles away. We’ve shared another of [Bob]’s HOA-friendly builds below as well which hides the HF antenna in the roof’s ridge vent, and if you’re looking for other interesting antenna builds take a look at this one which uses a unique transformer to get wide-band performance out of an otherwise short HF antenna.

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Cart Cruises Abandoned California Rail

February 25, 2023 by Bryan Cockfield 21 Comments

Southern California is known for its nearly perfect year-round climate, excellent surf, and extremely high cost of living, but once you get away from the coast things are radically different. Rural California has huge tracts of land run by the Bureau of Land Management (BLM), which is publicly accessible to anyone willing to venture into the deserts. There’s not much in the way of infrastructure out there, but [Ryan] does have a unique way of traveling through it using abandoned railroad lines and this custom rail cart.

The frame of this cart is simple enough, it’s little more than 2×3 framing with a plywood deck. Some extra support is added for the motor mount and for the seating location. It uses slightly longer go-kart axles to accommodate the width of the railroad, and a small six horsepower gas engine with a single gear to power the rear axle. There are no brakes other than the riders’ shoes, and while this all seems straightforward enough the real hack here is [Ryan]’s custom wheels. He found that steel or cast wheels were not particularly comfortable on long journeys so after a few attempts he has come up with a home-built polyurethane wheel which is cast in a mold around a steel go-cart wheel and then trimmed on a lathe.

For pure exploration, there’s almost no better place to go than the American west thanks to all the public BLM land available. In this cart, you can explore long distances using an extremely low-cost method of transportation. We’ve added another video of [Ryan] exploring this area below the break to show the cart being used, too, but if you’d like a more multipurpose vehicle to use on abandoned rail near you, take a look at this bicycle which is converted to operate on the railroad.

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