Easy Network Config For IoT Devices With RGBeacon

May 11, 2022 by Lewin Day 25 Comments

When you’re hooking up hardware to a network, it can sometimes be a pain to figure out what IP address the device has ended up with. [Bas Pijls] often saw this problem occurring in the classroom, and set about creating a simple method for small devices to communicate their IP address and other data with a minimum of fuss.

[Bas] specifically wanted a way to do this without adding a display to the hardware, as this would add a lot of complexity and expense to simple IoT devices. Instead, RGBeacon was created, wherin a microcontroller flashes out network information with the aid of a single RGB WS2812B LED.

In fact, all three colors of the RGB LED are used to send information to a computer via a webcam. The red channel flashes out a clock signal, the green channel represents the beginning of a byte, and the blue channel flashes to indicate bits that are high. With a little signal processing, a computer running a Javascript app in a web browser can receive information from a microcontroller flashing its LEDs via a webcam.

It’s a neat hack that should make setting up devices in [Bas]’s classes much easier. It needn’t be limited to network info, either; the code could be repurposed to let a microcontroller flash out other messages, too. It’s not dissimilar from the old Timex Datalink watches which used monitor flashes to communicate!

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 Arya Voronova 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.

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Tiny RISC Virtual Machine Is Built For Speed

April 28, 2022 by Bryan Cockfield 13 Comments

Most of us are familiar with virtual machines (VMs) as a way to test out various operating systems, reliably deploy servers and other software, or protect against potentially malicious software. But virtual machines aren’t limited to running full server or desktop operating systems. This tiny VM is capable of deploying software on less powerful systems like the Raspberry Pi or AVR microcontrollers, and it is exceptionally fast as well.

The virtual machine is built from scratch, including the RISC processor with only 61 opcodes, a 64 bit core, and runs code written in his own programming language called “Brackets” or in assembly. It’s designed to be modular, so only those things needed for a given application are loaded into the VM. With these design criteria it turns out to be up to seven times as fast as comparably small VMs like NanoVM. The project’s creator, [koder77], has even used its direct mouse readout and joystick functionality to control a Raspberry Pi 3D camera robot.

For anyone looking to add an efficient VM to a small computing environment, [koder77] has made the project open-source on his GitHub page. This also includes all of the modules he has created so far which greatly expand the project’s capabilities. For some further reading on exceedingly tiny virtual machines, we featured this project way back in 2012 which allows users to run Java on similar hardware.

Flashing TI Chips With An ESP

April 3, 2022 by Bryan Cockfield 29 Comments

Texas Instruments is best known to the general public for building obsolete calculators and selling them at extraordinary prices to students, but they also build some interesting (and reasonably-priced) microcontrollers as well. While not as ubiquitous as Atmel and the Arduino platform, they can still be found in plenty of consumer electronics and reprogrammed, and [Aaron] aka [atc1441] demonstrates how to modify them with an ESP32 as an intermediary.

Specifically, the TI chips in this build revolve around the 8051-core microcontrollers, which [Aaron] has found in small e-paper price tags and other RF hardware. He’s using an ESP32 to reprogram the TI chips, and leveraging a web server on the ESP in order to be able to re-flash them over WiFi. Some of the e-paper displays have built-in header pins which makes connecting them to the ESP fairly easy, and once that’s out of the way [Aaron] also provides an entire software library for interacting with these microcontrollers through the browser interface.

Right now the project supports the CC2430, CC2510 and CC1110 variants, but [Aaron] plans to add support for more in the future. It’s a fairly comprehensive build, and much better than buying the proprietary TI programmer, so if you have some of these e-paper displays laying around the barrier to entry has been dramatically lowered. If you don’t have this specific type of display laying around, we’ve seen similar teardowns and repurposing of other e-paper devices in the past as well.

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Careful Cuts Lets Logger Last A Year On A Coin Cell

March 14, 2022 by Bryan Cockfield 21 Comments

Coin cells are great for backup power for things like real-time clocks, or even for powering incredibly small mechanical devices like watches. But for something like a data logger, running on a standard microcontroller, most people would reach for a lithium cell of some sort. Not so with this build, though, which squeezes every joule of energy from a coin cell in order to run a data logger for a full year.

Most of the design and engineering required to improve the efficiency of the data logger involve standard practices for low-power devices such as shutting off unnecessary components and putting the device to sleep when not actively running, but this build goes far beyond that. The Vcc pin on the RTC was clipped which disables some of its internal logic but still keeps its basic functionality intact.

All of the voltage regulators were removed or disabled in favor of custom circuitry that doesn’t waste as much energy. The status and power LEDs were removed where possible, and the entire data logger is equipped with custom energy-efficient code as well.

If you’re starting a low-power project, even one that isn’t a datalogger, it’s worth checking out this build to see just how far you can go if you’re willing to hack at a PCB with cutting tools and a soldering iron. As to why this data logger needed such a low power requirement, it turns out it’s part of a kit being used in classrooms and using a coin cell brought the price of the entire unit down tremendously. Even if you have lithium cells on hand, though, it’s still worthwhile to check out the low power modes of your microcontroller.

Thanks to [Adrian] for the tip!

ESP32 Virtual Machine Lets You Change Programs On The Fly

February 27, 2022 by Lewin Day 30 Comments

Often, reprogramming a microcontroller involves placing it in reset, flashing the code, and letting it fire back up. It usually involves shutting the chip down entirely. However, [bor0] has built a virtual machine that runs on the ESP32, allowing for dynamic program updates to happen.

The code is inspired by the CHIP-8, a relatively ancient interpreter that had some gaming applications. [bor0] had already created a VM simulating the CHIP-8, and repurposed it here, taking out the gaming-related drawing instructions and replacing them with those that control IO pins. Registers have also been changed to 16 bits for added flexibility and headroom.

It’s probably not something with immediate ground-breaking applications for most people, but it’s a different way of working with and programming the ESP32, and that’s pretty neat.

The ESP32 is a powerful chip, too, as we all know – and it makes a great 8-bit emulator to boot. Sound off in the comments with your thoughts on what would make a killer application for the ESP32 VM!

[Thanks to satancete for the tip!]

Floppy Interfacing Hack Chat With Adafruit

January 31, 2022 by Dan Maloney 44 Comments

Join us on Wednesday, February 2 at noon Pacific for the Floppy Interfacing Hack Chat with Adafruit’s Limor “Ladyada” Fried and Phillip Torrone!

When a tiny fleck of plastic-covered silicon can provide enough capacity to store a fair percentage of humanity’s collected knowledge, it may seem like a waste of time to be fooling around with archaic storage technology like floppy disks. With several orders of magnitude less storage capacity than something like even the cheapest SD card or thumb drive, and access speeds that clock in somewhere between cold molasses and horse and buggy, floppy drives really don’t seem like they have any place on the modern hacker’s bench.

Or do they? Learning the ins and out of interfacing floppy drives with modern microcontrollers is at least an exercise in hardware hacking that can pay dividends in other projects. A floppy drive is, after all, a pretty complex little device, filled with electromechanical goodies that need to be controlled in a microcontroller environment. And teasing data from a stream of magnetic flux changes ends up needing some neat hacks that might just serve you well down the line.

So don’t dismiss the humble floppy drive as a source for hacking possibilities. The folks at Adafruit sure haven’t, as they’ve been working diligently to get native floppy disk support built right into CircuitPython. To walk us through how they got where they are now, Ladyada and PT will drop by the Hack Chat. Be sure to come with your burning questions on flux transitions, MFM decoding, interface timing issues, and other arcana of spinning rust drives.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, February 2 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

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