LED Wall Clock Gets Raspberry Pi Pico Upgrade

January 1, 2025 by Tom Nardi 11 Comments

When [Rodrigo Feliciano] realized that the reason his seven-segment LED wall clock wasn’t working was because the original TG1508D5V5 controller was fried, he had a decision to make. He could either chuck the whole thing, or put in the effort to reverse engineer how the displays were driven and replace the dead controller with something a bit more modern. Since you’re reading this post on Hackaday, we bet you can guess which route he decided to take.

If you happen to own the same model of clock as [Rodrigo], then you really lucked out. He’s done a fantastic job documenting how he swapped the original controller out for a Raspberry Pi Pico W, which not only let him bring the clock back to life, but let him add new capabilities such as automatic time setting via Network Time Protocol (NTP).

But even if you don’t have this particular clock there’s probably something you can learn from this project, as it’s a great example of practical reverse engineering. By loading a high-resolution image of the back of the PCB into KiCad, [Rodrigo] was able to place all the components into their correct positions and following traces to see what’s connected to what.

Pretty soon he not only had a 3D model of the clock’s PCB, but a schematic he could use to help wire in the Pi Pico. Admittedly this is a pretty straightforward PCB to try and reverse engineer, but hey, you have to start somewhere.

We had high hopes for KiCad’s image import feature when it was introduced, and it’s great to see real-world examples like this trickle in as more folks learn about it.

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VPlayer Puts Smart Display In Palm Of Your Hand

December 31, 2024 by Tom Nardi 18 Comments

It’s not something we always think about, but the reality is that many of the affordable electronic components we enjoy today are only available to us because they’re surplus parts intended for commercial applications. The only reason you can pick up something like a temperature sensor for literal pennies is because somebody decided to produce millions of them for inclusion in various consumer doodads, and you just happened to luck out.

The vPlayer, from [Kevin Darrah] is a perfect example. Combining a 1.69 inch touch screen intended for smartwatches with the ESP32-S3, the vPlayer is a programmable network-connected display that can show…well, pretty much anything you want, within reason. As demonstrated in the video below, applications range from showing your computer’s system stats to pulling in live images and videos from the Internet.

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38C3: Xobs On Hardware Debuggers

December 29, 2024 by Elliot Williams 3 Comments

If you just want to use a debugger for your microcontroller project, you buy some hardware device, download the relevant driver software, and fire up GDB. But if you want to make a hardware debugger yourself, you need to understand the various target chips’ debugging protocols, and then you’re deep in the weeds. But never fear, Sean [Xobs] Cross has been working on a hardware debugger and is here to share his learnings about the ARM, RISC-V, and JTAG debugging protocols with us.

He starts off with a list of everything you need the debugger hardware to be able to do: peek and poke memory, read and write to the CPU registers, and control the CPU’s execution state. With that simple list of goals, he then goes through how to do it for each of the target chip families. We especially liked [Xobs]’s treatment of the JTAG state machine, which looks pretty complicated on paper, but in the end, you only need to get it in and out of the shift-dr and shift-ir states.

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38C3: Towards An Open WiFi MAC Stack On ESP32

December 28, 2024 by Elliot Williams 15 Comments

At the 38th Chaos Communications Congress, [Frostie314159] and [Jasper Devreker] gave us a nice update on their project to write an open-source WiFi stack for the ESP32. If you’re interested in the ESP32 or WiFi in general, they’ve also got a nice deep dive into how that all works.

On the ESP32, there’s a radio, demodulator, and a media access controller (MAC) that takes care of the lowest-level, timing-critical bits of the WiFi protocol. The firmware that drives the MAC hardware is a licensed blob, and while the API or this blob is well documented — that’s how we all write software that uses WiFi after all — it’s limited in what it lets us do. If the MAC driver firmware were more flexible, we could do a lot more with the WiFi, from AirDrop clones to custom mesh modes.

The talk starts with [Jasper] detailing how he reverse engineered a lot of Espressif’s MAC firmware. It involved Ghidra, a Faraday cage, and a lucky find of the function names in the blob. [Frostie] then got to work writing the MAC driver that he calls Ferris-on-Air. Right now, it’s limited to normal old station mode, but it’s definite proof that this line of work can bear fruit.

This is clearly work in progress — they’ve only been at this for about a year now — but we’ll be keeping our eyes on it. The promise of the ESP32, and its related family of chips, being useful as a more general purpose WiFi hacking tool is huge.

Holiday Jukebox Gets ESP32, Home Assistant Support

December 24, 2024 by Tom Nardi 14 Comments

If we’ve learned anything over the years, it’s that the only thing hardware hackers love more than a device festooned with buttons is one that’s covered in LEDs — so it’s no surprise that this “Mr Christmas” jukebox caught the eye of [Roberts Retro]. But while the holiday gadget might have been mildly entertaining in its stock configuration, he quickly realized that what it really needed was an ESP32 retrofit. After all, what good are all those buttons and LEDs if you can’t bend them to your will?

For the first half of the video, [Robert] treats us to a detailed teardown of the device, which as you might imagine, is largely hollow inside. This gave him plenty of room to graft in new hardware, which is really the best gift any of us could hope to find under the tree. In addition to the ESP32 development board, the jukebox also received a number of WS2812B addressable RGB LEDs, and a DFPlayer module to handle music playback.

With all the buttons wired up to inputs on the ESP32, [Robert] can reconfigure the jukebox to do pretty much whatever he wants with just changes to the software. In the video, he demonstrates how the buttons can be used to trigger the playback of individual songs stored on the DFPlayer’s SD card, which essentially replicates it’s stock functionality. A few lines of changed code later, those same buttons can be used to control devices via Home Assistant.

To get into the holiday spirit, [Roberts Retro] shows off the completed jukebox controlling his ESP-enabled LEGO train set — another of his festive upgrades that we covered back in 2022.

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An LCD, Touch Sensor, USB-C, And A Microcontroller For A Buck

December 21, 2024 by Lewin Day 16 Comments

[CNLohr] has been tinkering with some fun parts of late. He’d found out that ordinary LCD screens could be used as simple touch sensors, and he had to try it for himself. He ended up building a little doohickey that combined USB C, an LCD display, and a touch interface, all for under a buck. You can check out the video below.

The key to this build was the CH32V003 CPU. It’s a RISC-V microcontroller that runs at a healthy 48 MHz, and it costs just 10 cents in reasonable quantities. A PCB etched to mate with a USB C cable eliminates the need for a connector.

[CNLohr] then gave the board a three-digit 7-segment LCD display from Aliexpress, which can be had for around 21 cents if you buy 100 or more. He then figured out how to drive the LCDs with a nifty trick that let the microcontroller use the display as a crude touch sensor. All in all, the total bill of materials for one of these things comes out somewhere under a dollar in quantity.

It’s mostly a random assemblage of tech glued together for a demo, but it’s a fun project. It’s worth checking out even if it’s just to learn how to create an integral USB C port on your own PCBs. The way it’s achieved with the etched contacts and milled-out tabs is pure elegance. Files are on Github for the curious.

We’ve featured a ton of [CNLohr’s] work over the years; the clear keytar was a glowing highlight, as were his early discoveries in the depths of the ESP8266.

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Rudolph’s Sleigh On A North Pole PCB

December 20, 2024 by Heidi Ulrich 18 Comments

Each Christmas, [Adam Anderson], [Daniel Quach], [Johan Wheeler], and [Gustav Abrahamsson] (going by ‘the Janky Jingle Crew’)—set themselves the challenge of outdoing their previous creations. Last year’s CH32 Fireplace brought an animated LED fire to life with CH32V003 microcontrollers.

This year, they’ve gone a step further with the North Pole Circuit, a holiday project that combines magnetic propulsion, festive decorations, and a bit of engineering flair. Inspired by a miniature speedway based on Friedrich Gauss’ findings, the North Pole Circuit includes sleighs and reindeer that glide along a custom PCB track, a glowing village with flickering lights, and a buzzer to play Christmas tunes.

The propulsion system works using the Lorentz force, where vertical magnets interact with PCB traces to produce motion. A two-phase design, similar to a stepper motor, ensures smooth operation, while guard rails maintain stability on curves. A separate CH32V003 handles lighting and synchronized jingles, creating a cohesive festive display. As we mentioned in the article on their last year’s creation, going from a one-off to a full batch will make one rethink the joy of repetitive production. Consider the recipients of these tiny Christmas cards quite the lucky ones. We deem this little gift a keeper to put on display when Christmas rolls around again.

This annual tradition highlights the Crew’s knack for combining fun and engineering. Curious about the details or feeling inspired to create your own? Explore the full details and files on their GitHub.