Year: 2022

The microcontroller described in the article, on the PCB taken out of the kettle

Dumping Encrypted-At-Rest Firmware Of Xiaomi Smart Kettle

May 4, 2022 by 52 Comments

[aleaksah] got himself a Mi Smart Kettle Pro, a kettle with Bluetooth connectivity, and a smartphone app to go with it. Despite all the smarts, it couldn’t be turned on remotely. Energized with his vision of an ideal smart home where he can turn the kettle on in the morning right as he wakes up, he set out to right this injustice. (Russian, translated) First, he tore the kettle down, intending to dump the firmware, modify it, and flash it back. Sounds simple enough — where’s the catch?

This kettle is built around the QN9022 controller, from the fairly open QN902X family of chips. QN9022 requires an external SPI flash chip for code, as opposed to its siblings QN9020 and QN9021 which have internal flash akin to ESP8285. You’d think dumping the firmware would just be a matter of reading that flash, but the firmware is encrypted at rest, with a key unique to each MCU and stored internally. As microcontroller reads the flash chip contents, they’re decrypted transparently before being executed. So, some other way had to be found, involving the MCU itself as the only entity with access to the decryption key.

Continue reading “Dumping Encrypted-At-Rest Firmware Of Xiaomi Smart Kettle” →

The module on a green PCB, connected to the Pixhawk controller, powering the servo rail

Anxieties Of Hardware Bringup During Parts Shortage

May 4, 2022 by 22 Comments

[Dirksavage88] tells us a story about developing a simple BEC in times of chip shortage. He needed a small 5V/3A regulator board for a servo rail on his drone, and decided to use one of the new integrated-inductor modules from Texas Instruments. Hardly requiring any external parts, such modules are exceptionally nice to use for all your power rail needs, albeit at a slightly increased cost – the downside is that, as the parts shortage hit, most of them have been out of stock. Originally priced at about $7 USD, the asking price for these specific modules, LMZM33603, has climbed as high as $800. Somehow, he obtained a few of these modules nevertheless, and went on designing a board.

It can be daunting to test your very first PCBs when the silicon you’re putting on it is effectively irreplaceable for your purposes. TI is known for their wacky footprints, and this module is no exception – the solder paste application took a bit of time, and seeing small solder balls around the module after reflow didn’t exactly reassure him. Thankfully, when he powered it all up, the module worked wonders, and took its rightfully earned spot in his drone’s servo turret. He says we can expect the next revision of his design in 2024, or whenever it is that the reported 100 week lead time is due. In case some of us could use them, Eagle files are available on GitHub!

Quite a few of us are lucky enough to have enough crucial parts for what we need, but most of us got a good few projects shelved until better times – take this WiFi-enabled wall charger project, for instance. Even bigger projects are suffering, from SmoothieBoard to Raspberry Pi. Just a year ago, we had our readers share their chip shortage stories.

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Designing For The Small Grey Screen

May 3, 2022 by 23 Comments

With the huge popularity of retrocomputing and of cyberdecks, we have seen a variety of projects that use a modern computer such as a Raspberry Pi bathed in the glorious glow of a CRT being used as a monitor. The right aesthetic is easily achieved this way, but there’s more to using a CRT display than simply thinking about its resolution. Particularly a black-and-white CRT or a vintage TV has some limitations due to its operation, that call for attention to the design of what is displayed upon it. [Jordan “Ploogle” Carroll] has taken a look at this subject, using a 1975 Zenith portable TV as an example.

The first difference between a flat panel and a CRT is that except in a few cases it has a curved surface and corners, and the edges of the scanned area protrude outside the edges of the screen. Thus the usable display area is less than the total display area, meaning that the action has to be concentrated away from the edges. Then there is the effect of a monochrome display on colour choice, in other words the luminance contrast between adjacent colours must be considered alongside the colour contrast. And finally there’s the restricted bandwidth of a CRT display, particularly when it fed via an RF antenna socket, which affects how much detail it can reasonably convey. The examples used are games, and it’s noticeable how Nintendo’s design language works well with this display. We can’t imagine Nintendo games being tested on black-and-white TV sets in 2022, so perhaps this is indicative of attention paid to design for accessibility.

While they require a bit of respect due to the presence of dangerous voltages, there’s a lot of fun to be had bringing a CRT into 2022. Get one while you still can, and maybe you could have a go at a retro cyberdeck.

The LED tree itself , filmed in the dark - a myriad of small orbs glowing mictures of green, blue and warm white

Kaleidoscope – Feelings Turned Into LED Tree

May 3, 2022 by 4 Comments

In 2020, [Eddie] found himself with a few hundred RGB LEDs left after a pandemic-interrupted project, and a slew of emotions he wanted to express – so he turned to the language of hardware, and started sculpting his feelings into an art project. He set out to build an LED tree around a piece of wood he picked for its cool shape, and trying out a long-shelved idea of his, while at it – using different resistors to mix colors of the RGB LEDs. The end result, pictured above, has earned “The Most Important Device” spot in our recent Sci-Fi contest, fair and square.

Initially, he wanted to use ATTiny microcontrollers and PWM all the lights in parallel. Having built an intermediate prototype, a small LED flower, he scrapped the idea due to technical problems, and then simplified it by hard-wiring RGB LEDs with randomly selected colors instead. As for the glowing orbs themselves, he made these just by pouring hot glue into silicon orb molds, a simple technique any of us could repeat. After 90 hours of work between him and an assistant he hired, the LEDs were wired up, each with random resistors connected to green and blue LED colors, and some warm white LEDs added into the mix.

He wanted to mostly use blue and green colors, as symbols of a world revived and revitalized – something we can’t help but keep our fingers crossed for. Before putting it all together, they wouldn’t know which colors each of the LEDs would power up in – part of the charm for this art piece, and no doubt a pleasant surprise. In the end, it turned out to be a futuristic decoration that we’re glad a camera could capture properly! If you like what you see, the build logs linked above have a bit more insights into how it all came together.

LED-adorned plants are fun projects that bring joy for a long time after you’ve finished them. You can easily make a LED tree out of what you have on hand, and if you get real fancy, you can create an intricate bonsai, too. And, if you’re ever interested to experiment with castellations, you can design yourself some PCB cube flowers!

This project was an entry into the 2022 Sci-Fi Contest. Check out all of the winning entries here.

Photo rail setup for stop motion

Stop-Motion Angels In The Light Field

May 3, 2022 by No comments

Baseball jokes aside, holograms have been a dream for decades, and with devices finally around that support something like them, we have finally started to wonder how to make content for them. [Mike Rigsby] recently entered his stop-motion holographic setup into our sci-fi contest, and we love the idea.

Rather than a three-dimensional model or a 2d picture with pixels, the Looking Glass light field display supports a series of images as quantized points (hence light field). As you move around an object, images are interpolated between the frames you do know, giving a pretty convincing effect. In a traditional stop motion animation, you need to take anywhere between 12-24 frames to equal about one second of animation. Now that you need to take 48 pictures for one frame, over 1152 pictures for just one second of animation. Two problems quickly appear, how to take photographs accurately from the same position every time and how do you manage the deluge of photos sensibly. [Mike] started with a wooden stage for his actors. A magnet was mounted to the photo rail carriage, and a sensor allowed it to detect that it was in the same spot. An Arduino controls the rail, reads the magnet via a sensor, and controls the camera shutter. The DSLR he’s using can’t do that many frames per second, but that’s a problem for another sci-fi contest.

Holographic-ish displays are finally here, and they’re getting better. But if a display isn’t your speed, perhaps some laser-powered glasses can be the holographic experience you’re looking for?

This project was an entry into the 2022 Sci-Fi Contest. Check out all of the winning entries here.

A square PCB with a Raspberry Pi Pico mounted in the middle

Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer

May 3, 2022 by 37 Comments

If you’re a radiation enthusiast, chances are you’ve got a Geiger counter lying around somewhere. While Geiger counters are useful to detect the amount of radiation present, and with a few tricks can also distinguish between the three types of radiation (alpha, beta and gamma), they are of limited use in identifying radioactive materials. For that you need a different instrument called a gamma-ray spectrometer.

Spectrometers are usually expensive and complex instruments aimed at radiation professionals. But it doesn’t have to be that way: physics enthusiast [NuclearPhoenix] has designed a hand-held gamma spectrometer that’s easy to assemble and should fit in a hobbyist budget. It outputs spectral plots that you can compare with reference data to identify specific elements.

A PCB with a sensor wrapped in black tape
The scintillator and sensor are wrapped in black tape to block out ambient light.

The heart of the device is a scintillation crystal such as thallium-doped sodium iodide which converts incoming gamma rays into visible light. The resulting flashes are detected by a silicon photomultiplier whose output is amplified and processed before being digitized by a Raspberry Pi Pico’s ADC. The Pico calculates the pulses’ spectrum and generates a plot that can be stored on its on-board flash or downloaded to a computer.

[NuclearPhoenix] wrote a convenient program to help analyze the output data and made all design files open-source. The hardest part to find will be the scintillation crystal, but they do pop up on auction sites like eBay now and then. We’ve featured an Arduino-based gamma spectrometer before; if you’ve always wanted to roll your own scintillators, you can do that too. Continue reading “Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer” →

Fireball-Flinging Figurine Feeds Fiction

May 3, 2022 by 7 Comments

If you’re writing a screenplay or novel, there will likely be points along the way at which you can’t get enough encouragement from friends and family. While kind words are kind, acts such as [scubabear]’s can provide a push like no other. By commissioning another 3D designer friend to model a character from the first friend’s screenplay so he could print and animate it, [scubabear] fed two birds with one scone, you might say.

Designer friend [Sean] modeled the mighty Braomar in Maya and Z-brush, and [scubabear] did test prints on a Formlabs Form2 as they went along to keep an eye on things. Eventually, they had a discussion about making space for wires and such, so [Sean] took to Blender to make Braomar hollow enough for wires, but not so empty that he would collapse under the stress of being (we presume) the main character.

Braomar stands upon a sigil that changes color thanks to an RGB LED ring in the base that’s driven by an Arduino Nano. A single pixel in the fireball is wired through Braomar’s body and flickers with the help of an addressable LED sequencer board.

Our favorite part of this build has to be the power scheme. Not content to have a wire running out from the base or even a remote control for power-draining concerns, [scubabear] used disc magnets in the base to switch on the 9 V battery when Screenplay Friend rotates it.

Of course, if you need inspiration to even thing about beginning to write a screenplay or novel, maybe you should lead with the maquette-building and then construct a story around your creation.

This project was an entry into the 2022 Sci-Fi Contest. Check out all of the winning entries here.