Month: January 2023

Low-Cost 433 MHz Door Sensors Get Open Firmware

January 8, 2023 by 38 Comments

It’s an unfortunate reality these days that if you see a cheap piece of consumer electronics, there’s a good chance its only cheap because it’s designed to lock you into some ecosystem where you’ll either end up paying a subscription, or worse, have your personal information sold behind your back. One of the best tools we have against these sort of anti-consumer practices is the development of open source firmware replacements that put control of the device into the hands of the community, rather than a corporation.

Now, thanks to the work of [Jonathan Armstrong] we have such a firmware for the 433 MHz magnetic door and window sensors that you can pick up on AliExpress for $4 USD a piece. The new firmware not only ensures you can use these sensors with a wide array of receivers, but adds a number of new features over their stock configuration. Continue reading “Low-Cost 433 MHz Door Sensors Get Open Firmware” →

Forth Cracks RISC-V

January 8, 2023 by 49 Comments

Over the decades there have been many programming languages, some of which have flowered briefly, and others that have stuck around despite newer, better, and faster competition. Few languages embody this last group more than FORTH, over five decades old and still cropping up wherever a simple, elegant, fast, and compact stack-based programming language fits the bill. [Alexander Williams] has now taken it somewhere new, with a FORTH in RISC-V assembly which runs on the GD32 series of microcontrollers that are RISC-V lookalikes of the popular STM32 ARM parts.

We have to admit to last having used FORTH on an 8-bit home computer in the 1980s, aside from a moment’s idle play on discovering that the Open Firmware on Apple computers is a FORTH interpreter. Thus we’re intrigued by this implementation, but not from a position of FORTH expertise. We’d expect such an efficient language to be extremely quick though, so it’s definitely something to keep an eye on for when a suitable dev board comes our way. If it interests you, take a look at the GitHub repository.

The GitHub Silverware Drawer Dilemma, Or: Finding Active Repository Forks

January 8, 2023 by 11 Comments

An fortunate reality of GitHub and similar sites is that projects that are abandoned by the maintainer are often continued by someone else who forked the project. Unfortunately, the ease of forking also means that GitHub projects tend to have a lot of forks, with the popular projects having hundreds of them. Since GitHub has elected to not provide a way to filter or sort these forks, finding the most active fork can be rather harrowing.

In addition, a popular project’s dead repository tends to score higher in search results than replacement forks. For these particular situations a couple of very useful websites and browser add-ons have been developed. The Lovely Forks add-on by [Utkarsh Upadhyay] seeks to insert information on forks that are notable or newer than the repository one is looking at.

Meanwhile, the Active Forks project by [Samar Dhwoj Acharya] provides a sortable list of project forks when provided with a GitHub repository name. This helps enormously when trying to find the freshest forks in a whole list. This is similar to the Useful Forks project that provides a web-based interface in addition to a Chrome extension. Do note that these queries will count towards the GitHub API rate-limits, so you may need to add an access token.

It’s a shame that GitHub doesn’t offer such functionality by default, but thanks to these projects the times of clicking through a hundred forks to find the freshest one is at least over. For now.

Release Less Magic Smoke, With A Bulb Limiter

January 8, 2023 by 29 Comments

As electronics have moved lower in voltage, it’s perhaps less common to work on live-mains equipment. Thus particularly among younger hardware hackers it sometimes seems as though such work is viewed as so dangerous as to be only for the foolhardy. In practice it remains safe, so long as appropriate precautions are taken and a few pieces of useful safety equipment are present. One of those mains bench essentials is something less common in 2022, a mains current limiter using a set of switched incandescent light bulbs. [Donna LaRocco] shares a modern take on the idea, incorporating a digital mains voltmeter.

The idea is that a mains device under test is connected in series with a light bulb of a suitable wattage to let through enough current to run the device in normal operation, but to light up and bring down the voltage if the device draws too much. It’s an extremely simple but effective tool. Traditionally these are built using household electrical fittings on a board, and this one is no exception. The voltmeter comes from the RV market where voltage drop is an issue, no doubt giving European readers a chance to chuckle with their 230 V outlets.

If mains safety needs your attention, it’s a subject we’ve addressed in the past.

Classic Video Chip Drives A Modern TFT

January 7, 2023 by 11 Comments

A lot of us have a soft spot for retrocomputers, and there’s nothing quite like running original hardware. Unfortunately if you’re after the truly original touch then that means carrying along the family TV from 1982, and that’s where life becomes annoying. What if there were a way you could easily drive an LCD panel from a classic video controller? Help is at hand for owners of TI TMS9928A video chips, courtesy of [umaker], with a clever interface board that drives an SPI or parallel TFT.

At its heart is not the FPGA you might expect, but an STM32G4 microcontroller on an STM Nucleo board. This digitizes the R-Y and Y components from the TMS chip which would originally have been destined for an NSC or PAL encoder, does the color conversion through its algorithm, and transfers the result to the screen. This is a task which would back in the day when NTSC or PAL were king have been seen as extremely computationally intensive, so it’s a mark of just how capable an STM can be that a few dollar microcontroller can do it.

We can see this technique proving to be extremely useful across a lot of different retro color graphic applications. We’re not sure whether its lag would be too much for a light gun game, but it would be nice to think that it would result in handheld retro machines.

We encountered this project previously, when as part of its development he needed a sync separator.

Tiny Robots That Bring Targeted Drug Delivery And Treatment A Little Bit Closer

January 7, 2023 by 8 Comments

Within the world of medical science fiction they are found everywhere: tiny robots that can zip through blood vessels and intestines, where they can deliver medication, diagnose medical conditions and even directly provide treatment. Although much of this is still firmly in the realm of science-fiction, researchers at Stanford published work last year on an origami-based type of robots, controlled using an external magnetic field. Details can be found in the Nature Communications paper. Continue reading “Tiny Robots That Bring Targeted Drug Delivery And Treatment A Little Bit Closer” →

Gorgeous Sunflower Macropad Will Grow On You

January 7, 2023 by 3 Comments

Once [Hide-key] saw the likes of the banana and corn macro pads, they knew they had to throw their hat in this strange and wonderful ring. Some family members suggested a sunflower, and off they went looking for inspiring images, finally settling on a more iconic and less realistic design which we think is quite beautiful.

This lovely little macro pad has seven keys hiding under those petals, with the eighth major petal concealing a XIAO RP2040 microcontroller. The rest of the major petals actuate a low-profile Kailh choc in — what else? — brown. Don’t worry, the middle isn’t a wasteland — there’s a low-profile rotary encoder underneath. Part of the reason this flower looks so great is that [Hide-key] started with SLA prints, but the paint choices are aces as well. If you’d like to grow your own sunflower, everything about this garden is open-source.

Oh yes, we totally covered the banana and the banana split, though we must have missed out on the corn. We hear that when you try it with butter, everything changes.

Via KBD #109