Super Simple Deadbuggable Bluetooth Chip

December 9, 2025 by 4 Comments

We’re all used to Bluetooth chips coming in QFN and BGA formats, at a minimum of 30-40 pins, sometimes even a hundred. What about ten pins, with 1.27 mm pitch? [deqing] from Hackaday.io shows us a chip from WCH, CH571K, in what’s essentially a SO-10 package (ESSOP10). This chip has a RISC-V core, requires only three components to run, and can work Bluetooth through a simple wire antenna.

This chip is a RISC-V MCU with a Bluetooth peripheral built in, and comes from the CH57x family of WCH chips that resemble the nRF series we’re all used to. You get a fair few peripherals: UART, SPI, and ADC, and of course, Bluetooth 4 with Low Energy support to communicate with a smart device of your choice. For extra hacker cred, [deqing] deadbugs it, gluing all components and a 2.54 mm header for FTDI comms onto the chip, and shows us a demo using webBluetooth to toggle an LED through a button in the browser.

You need not be afraid of SDKs with this one. There’s Arduino IDE support (currently done through a fork of arduino_core_ch32) and a fair few external tools, including at least two programming tools, one official and one third-party. The chip is under a dollar on LCSC, even less if you buy multiple, so it’s worth throwing a few into your shopping cart. What could you do with it once received? Well, you could retrofit your smoke alarms with Bluetooth, create your own tire pressure monitors, or just build a smartphone-connected business card!

PCB Design Review: TinySparrow, A Module For CAN Hacking, V2

December 9, 2025 by No comments

A year ago, I’ve design reviewed an MCU module for CAN hacking, called TinySparrow. Modules are plenty cool, and even more so when they’re intended for remaking car ECUs. For a while now, every car has heavily depended on a computer to control the operation of everything inside it – the engine and its infrastructure, the lights, and  Sadly, ECUs are quite non-hackable, so building your own ECUs only makes sense – which is why it’s heartwarming to see modules intended to make this easier on the budding ECU designer!

Last time we saw this module, it was quite a bit simpler. We talked about fixing a number of things – the linear regulator, the unprotected CAN transceiver, and the pinout; we also made the board cheaper to produce by reducing the layer count and instead pushing the clearance/track width limits. This time, we’re seeing TinySparrow v2 , redesigned accounting for the feedback and upgraded with a new MCU – it’s quite a bit more powerful!

For a start, it’s got ESD diodes, a switching-linear regulator chain for clean but efficient power supply, and most importantly, an upgraded MCU, now with USB and one more CAN channel for a total of two! There’s a lot more GPIOs to go around, too, so the PCB now uses all four of its sides for breakout out power, programming, and GPIO pads. Only a tiny bit bigger than its v1, this module packs a fair bit of punch.

Let’s revisit the design, and try to find anything still left to improve – there’s a few noteworthy things I found.

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The EFF Nails It: What’s Wrong With UK Digital ID

December 9, 2025 by 16 Comments

It sometimes seems as though we are in a constant tussle over privacy between governments and the governed, with each year bringing fresh attempts to extend surveillance, and consequent battles. For Brits the big news at the moment comes in a new digital ID scheme, something that will be required for anyone wishing to work in the country, as well as for certain government services. It’s something that has attracted a lot of opposition, and now the EFF have produced an analysis  of why they think it won’t work.

From the perspective of a British writer it would be easy to write screeds about the flaws in the scheme, the way it over-reaches, and about the historical distrust of Brits for their government’s bureaucracy. With the parliamentary petition opposing it approaching three million signatures, there’s no shortage of people who don’t support it. Perhaps the most obvious thing for most of us is how unnecessary it is for its stated aim of preventing illegal immigrants from seeking employment, it neglects that we already have to show proof of right to work before being hired, and that if crooked employers ignore that they will surely also ignore the digital ID.

If you’re reading this elsewhere in the world from where this is being written then it’s still of relevance, because governments like to point to other countries to justify these measures. Follow the EFF on this matter, and take note.

Art: British Passport SVG by Swapnil1101, Public Domain

LED Hourglass Is A Great Learning Project

December 9, 2025 by 2 Comments

An hourglass tells you what it is in the name — a glass that you use to measure an hour of time passing by. [EDISON SCIENCE CORNER] has built a digital project that mimics such a thing, with little beads of light emulating falling sand in the timekeepers of old.

The build is designed around the Arduino platform, and can be constructed with an Arduino Uno, Nano, or Pro Mini if so desired. The microcontroller board is hooked up with an ADXL335 three-axis accelerometer, which is used for tracking the orientation and movement of the digital hourglass. These movements are used to influence the movement of emulated grains of sand, displayed on a pair of 8×8 LED matrixes driven by a MAX7219 driver IC. Power is courtesy of a 3.7 V lithium-ion cell, with a charge/boost module included for good measure. Everything is wrapped up in a vaguely hourglass-shaped 3D printed enclosure.

The operation is simple. When the hourglass is turned, the simulated grains of sand move as if responding to gravity. The movement is a little janky — no surprise given the limited resolution of the 8×8 displays. You also probably wouldn’t use such a device as a timer when more elegant solutions exist. However, that’s not to say builds like this don’t have a purpose. They’re actually a great way to get to grips with a microcontroller platform, as well as to learn about interfacing external hardware and working with LED matrixes. You can pick up a great deal of basic skills building something like this.

Would you believe this isn’t the first digital hourglass we’ve featured on the site?

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RP2350 Done Framework Style

December 8, 2025 by 12 Comments

Ever want a microcontroller addon for your laptops? You could do worse than match one of the new and powerful microcontrollers on the block to one of the most addon-friendly laptops, in the way the Framework RP2350 laptop card does it. Plug it in, and you get a heap of USB-connected IO coming out of the side of your laptop – what’s not to love?

The card utilizes the Framework module board space to the fullest extent possible, leaving IO expansion on SMD pads you could marry to a male or female header, your choice. With about seventeen GPIOs, power, and ground, there’s really no limit on what you could add to the side connector – maybe it’d be a logic analyzer buffer, or a breadboard cable, or a flash chip reader, maybe, even an addon to turn it into a pirate version of a Bus Pirate? There’s a fair few RP2350 peripherals available on the side header GPIOs, so sky’s the limit.

Naturally, the card is fully open-source, and even has two versions with two different USB-C plug connectors, we guess, depending on which one is better liked by your PCBA process. Want one? Just send off the files! Last time we saw an addon adding GPIOs to your laptop, it was a Pi Zero put into the optical bay of a Thinkpad, also with an expansion header available on the side – pairing yet another legendary board with a legendary laptop.

The Engineering That Makes A Road Cat’s Eye Self-Cleaning

December 8, 2025 by 18 Comments

Although most people manage to navigate roads without major issues during the day, at night we become very reliant on the remaining navigational clues. The painted marks on the asphalt may not be as obvious in the glare of headlights, not to mention scuffed up and/or covered by snow and hidden by fog. This is where cat’s eyes are a great example of British ingenuity. A common sight in the UK and elsewhere in Europe, they use retroreflectors embedded in the road. Best of all, they are highly durable and self-cleaning, as [Mike Fernie] details in a recent video on these amazing devices.

Invented in the 1930s by [Percy Shaw], cat’s eyes feature a sturdy body that can take the abuse of being driven over by heavy trucks, along with a rubber dome that deforms to both protect the reflectors and wipe them clean using any water that’s pooled in the area below them. They also provide an auditory clue to the driver when they pass the center line, which can be very useful for night-time driving when attention may be slipping.

In the video the cat-squishing cleaning process is demonstrated using an old cat’s eyes unit that seems to have seen at least a few decades to road life, but still works and cleans up like a charm. Different color cat’s eyes are used to indicate different sections of the road, and modern designs include solar-powered LEDs as well as various sensors to monitor road conditions. Despite these innovations, it’s hard to beat the simplicity of [Percy]’s original design.

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Build Yourself A Graphing Weather Display

December 8, 2025 by 3 Comments

These days, Internet connectivity is ubiquitous, so you can look up live weather data on just about any device around you. Regardless, [Jozerworx] wanted a simple, clean, independent weather display, and came up with this simple design. 

The build is based on the Lilygo T5 EPD devboard, which combines an ESP32-S3 microcontroller with a nice 4.7-inch e-paper display. This display has the benefit that it only uses power when it’s being updated, making it particularly suitable to run off a battery for extended periods of time. Meanwhile, the ESP32 and its inbuilt Wi-Fi connectivity allow it to query the internet for updated weather forecasts. Weather data is sourced via the OpenWeather API, which [Jozerworx] notes comes with the caveat of requiring an API key. It’s a little fussy, but if you want good weather data, there are few easier ways to get it. The display shows a forecast for the next five days, while also showing graphs of ambient temperature and humidity along with useful information like the sunset and sunrise schedule.

Files are on Github for those eager to learn more. [Jozerworx] also notes that getting started with the display is particularly easy with the inclusion of a setup mode. This allows the display to act as a Wi-Fi access point with a web page that you use enter your home Wi-Fi connection details.

We’ve featured a great many charming weather displays over the years, too. If you’re working to plot, chart, or even predict the weather—don’t hesitate to show us your cool projects over on the tipsline!

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