zigbee

52 Articles

E-Paper Wall Paper

March 15, 2023 by 7 Comments

Just like the clock clock of old, there’s something magical about a giant wall of smaller pieces working together to make a larger version of that thing. The E-Paper Wall 2.0 by [Aaron Christophel] is no exception as it has now upgraded from 2.9″ to 7.4″ screens.

On the 1.0 version, the bezels made it harder to make out the image. The larger screens still have bezels but the larger screen area makes it much easier to make out the image. 3D-printed clips hold the displays onto a plywood backer. We can marvel that e-ink price tags brought the price of e-ink down so that building a wall is still expensive but not eye-wateringly so. The 5×9 array likely uses a module sold on DigiKey for $47 each.

So aside from being willing to drop some money on a custom piece of art, what’s special about this? The real magic comes with the firmware and tooling that [Aaron] developed to flash custom firmware onto each of the 45 displays. A 100MHz ZBS243/SEM9110 8051-based controller lives inside each display and [Aaron] even has a Ghidra plugin to reverse-engineer the existing firmware. It only has 64kb of flash onboard, so [Aaron] devised a clever compression technique that enabled him to store complex images on the displays. A 3D-printed jig with pogo pins means flashing them doesn’t require soldering pins or headers, just drop it on and flash it with an Arduino with a helpful library [Aaron] wrote. A central station communicates with the various displays over ZigBee to send image updates.

The 8051 has a funny way of showing up in projects like this portable soldering iron or the TV Guardian. In many ways, it is a boon for us hackers as it makes it easier to reverse engineer and write new custom firmware when so many devices use the same architecture.

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E-paper Price Tags Combined To Create A Large Wireless Display

August 5, 2022 by 3 Comments

E-paper price tags have become popular for retail stores over the past few years, which is great for hackers since we now have some more cheap commodity hardware to play with. [Aaron Christophel] went all on creating grid displays with E-paper price tags, up to a 20×15 grid.

E-paper price tags are great for these kinds of projects, since they are wireless, lightweight, and can last a long time with the onboard batteries. To mount the individual tags on the plywood backboard,[Aaron] simply glued Velcro to the backboard of the tags. The displays’ firmware is based on the reverse engineering work of [Dmitry Grinberg], flashed to a few hundred tags using a convenient 3D printed pogo pin programming jig. All the displays are controlled via a Zigbee USB dongle plugged into a PC running station software.

[Aaron] is also experimenting with the displays removed from their enclosure and popped into a 3D printed grid frame. The disadvantage is the loss of the battery holders and the antenna, which are both integrated into the enclosure. He plans to get around this by powering the displays from a single large battery, and connecting an ESP32 to the displays via ISP or UART.

This project comes hot on the heels of another E-ink grid display project that uses Bluetooth and a rather clever update scheme.

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New Part Day: An ESP With ZigBee

August 4, 2021 by 26 Comments

It seems that the folks at Espressif are doing their best to produce chips to fit every possible niche in the microcontroller-with-radio market, because here comes news of their latest chip bearing the ESP32 name: a single-core 96MHz RISC-V part with built-in IEEE 802.15.4 to support ZigBee 3.x and Thread 1.x. The ESP32-H2 is not the most powerful of the Espressif line-up, but it will find its place in home automation products and projects.

The ESP32-H2 joins a multitude of other IEEE 802.15.4 devices from manufacturers such as Microchip, ST, NXP, and Nordic in an increasingly crowded marketplace, so what can if offer that the others can’t? If previous ESP chips are anything to go by we’d expect it to compete on price as well as the obvious attraction for developers used to working with other Espressif products. We look forward as always to seeing what you do with it.

Hacking The Lidl Home Gateway

June 12, 2021 by 21 Comments

For years, Europeans have been browsing the central aisles of the German Aldi and Lidl supermarket chains, attracted by the surprising variety of transitory non-grocery bargains to be found there. There are plenty of temptations for hackers, and alongside the barbecues and Parkside tools at Lidl last year was a range of Zigbee home automation products. Every ZigBee network requires some form of hub, and for Lidl this comes in the form of a £20 (about $28) Silvercrest Home Gateway appliance. It’s a small embedded Linux computer at heart, and [Paul Banks] has published details of how it can be hacked and bent to the user’s will.

Under the hood is a Realtek RTL8196E MIPS SoC with 16Mb of Flash and 32 Mb of memory. Gaining control of it follows the well trodden path of finding the bootloader, dumping the firmware, and re-uploading it with a known password file. If you’ve done much hacking of routers and the like you’ll recognise that this quantity of memory and Flash isn’t the most powerful combination so perhaps you won’t be turning it into a supercomputer, but it’s still capable enough to be integrated with Home Assistant rather than the cloud-based services with which it shipped.

There was a time when repurposing routers as embedded Linux machines was extremely popular, but it’s something that has fallen from favour as boards such as the Raspberry Pi have provided an easier path. So it’s good to see a bit of old-fashioned fun can still be had with an inexpensive device.

If you fancy a bit more German budget supermarket goodness, feast your eyes on an Aldi stick welder!

A Deep Dive Into E-Ink Tag Hacking

March 28, 2021 by 7 Comments

Over the last decade or so, e-ink price tags have become more and more ubiquitous, and they’ve now reached the point where surplus devices can be found inexpensively on various websites. [Dmitry Grinberg] found a few of these at bargain-basement prices and decided to reverse engineer and hack them into monochrome digital picture frames.

Often, the most difficult thing about repurposing surplus hardware is the potential lack of documentation. In the two tags [Dmitry] hacked, not only are the labels not documented at all, one even has an almost-undocumented SoC controlling it. After some poking around and some guesswork, he was able to find connections for both a UART and an SWD debugging interface. Fortunately, the manufacturers left the firmware unprotected, so dumping it was trivial.

Even with the firmware dumped, code for controlling peripherals (especially wireless devices) is often inscrutable. [Dmitry] overcomes this with a technique he calls “Librarification” in which he turns the manufacturer’s firmware into libraries for his custom code. Once he was able to implement his custom firmware, [Dmitry] developed his own code to wirelessly download and display both gray-scale and two-color images.

Even if you’re not interested in hacking e-ink tags, this is an incredible walk-through of how to approach reverse-engineering an embedded or IoT device. By hacking two different tags with completely different designs, [Dmitry] shows how to get into these systems with intuition, guesswork, and some sheer persistence.

If you’d like to see some more of [Dmitry]’s excellent reverse-engineering work, take a look at his reverse-engineering and ROM dump of the PokeWalker. If you’re interested in seeing what else e-ink tags can be made to do, take a look at this weather station made from the same 7.4″ e-ink tag.

Making Smart Bulbs Smarter With The Power Of MQTT

December 25, 2020 by 14 Comments

What’s the point of smart home automation? To make every day tasks easier, of course! According to [Tomasz Cybulski], that wasn’t the case when he installed IKEA smart lights in his closet. It’s handy to have them in a common switch, in this case a remote control, but having to look for it every time he needed the lights could use some improvement. Enter his project to make smart bulbs smarter, through the use of a simple ESP8266.

While hooking a door switch to the lights’ power supply could provide a quick solution, [Tomasz]’s wife wanted to keep the functionality of the remote control, so he had to look elsewhere. These light bulbs use the simple Zigbee protocol, so arranging for other devices was rather trivial. A USB dongle to interface with the protocol was configured for his existing Raspberry Pi automation controller, while an ESP8266 served as the real-world sensor by connecting it to reed switches installed in the closet doors.

With all the hardware sorted out, it’s a simple matter of making it all talk to each other. The ESP8266, using the Tasmota firmware, sends a signal to an MQTT server running on the Raspberry Pi, which in turn translates it to a remote trigger on the Zigbee frequency with the dongle. The lights turn on when the door opens, and off again once it closes. And since there were no further modifications to the lights themselves, the original IKEA controller still works as expected, which we’re sure [Tomasz]’s wife appreciates!

MQTT can be an interesting piece of software that goes beyond just home automation though, and if you already have a server in your home you can use it to transfer your clipboard’s contents to another device. If you are using it for home automation though, here’s an inspiration for a rather unusual dashboard to keep things interesting. Check out this hack in action after the break.

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Another IoT Debacle: Charter Offers Home Insecurity

January 18, 2020 by 38 Comments

If you are a glass-half-empty person, you’ll view Charter’s announcement that they will shutter their home security and smart home service on February 5th as another reason not to buy into closed-source IoT devices. If you are a glass-half-full person though, you’ll see the cable company’s announcement as a sign that a lot of Zigbee hardware will soon flood the surplus market. Ars Technica reports that after investigation it appears that some of the devices may connect to a standard Zigbee hub after a factory reset, but many others will definitely not.

As you might expect, users were less than thrilled. Especially those that shelled out thousands of dollars on sensors and cameras. This sort of thing might be expected if a company goes out of business, but Charter just doesn’t want to be in the home security business anymore.

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