Author: Jenny List

3370 Articles

This ESP32 CAN!

October 10, 2022 by 15 Comments

Since modern cars use the CAN bus for so many of their functions, it’s unsurprising that it’s a frequent object of interest for those in our community. Some people go no further than commercial plug-in analysers, while others build their own CAN devices. This is what [Magnus Thomé] has done, with his RejsaCAN microcontroller board.

It’s a small PCB with an onboard CAN interface from an ESP32-S3 and a car-friendly power supply circuit, and perhaps most importantly, it has an auto-shutdown feature to prevent battery drain. Software-wise it’s a blank piece of paper for the user to roll their own application, but since the ESP32 is supported by the Arduino ecosystem, there are libraries that make talking CAN as easy as it can be.

[Magnus] has a list of potential applications for the board, many of which take advantage of the ESP’s wireless capabilities. So far, [Magnus] has hooked it up to an LCD display, but we can see so many other useful things coming out powered by something like this.

You haven’t tried playing with your car’s CAN bus yet? Maybe you should read this to whet your appetite.

A Rail Cart For The Space Conscious Passenger

October 8, 2022 by 29 Comments

For those who live in countries where there are plenty of abandoned railways, a popular way to explore them has been by means of home made rail carts. These are usually rudimentary rail trolleys with a small internal combustion engine, and a host of fascinating videos of them can be found online. Such a trolley has one disadvantage though — it’s not the most compact of devices. [Cato] has come up with a rail cart that’s extremely portable by replacing the engine with the guts of a pair of hoverboards.

The chassis of the machine is made from aluminium extrusion, and its deck from plywood. The wheels are the stock hoverboard wheels with flat flanges applied, which while they don’t have the ideal flange profile of a rail wheel are good enough to keep the thing on track. Finally to control the thing a rather stylish little 3D printed single-axis joystick serves as a combined throttle and brake.

Those of us who hail from places where abandoned railways have their track speedily ripped up can only gaze in envy and imagine speeding along the rails on one of these. The build starts with a warning never to use one of these on an active track, but should you wish to drive a real train there are plenty of places to do that.

Engineers: Be Subversive To Be Green

October 7, 2022 by 153 Comments

The caterers for the volunteer workforce behind the summer’s MCH hacker camp in the Netherlands served all-vegan food. This wasn’t the bean sprouts and lentils that maybe some of the more meat-eating readers might imagine when confronted with vegan food, nor was it a half-as-good array of substitutes with leathery soy hamburgers and rubbery fake cheese smelling suspiciously of feet.

Instead it was a well-crafted, interesting, and tasty menu that was something to look forward to after several hours driving a vanload of handwashing sinks. It was in one of their meals that I found food for thought when driving a week later past the huge Garzweiler open-cast lignite mine on my way through Germany to Luxembourg’s Haxogreen as part of my European hacker camp summer tour.

The meal was deep-fried soy protein strips and the mine is probably one of Western Europe’s dirtiest and most problematic CO2 sources in a country that likes to imagine itself as environmentally friendly, so where in this unlikely connection did I find a pairing? Continue reading “Engineers: Be Subversive To Be Green” →

A CRT Monitor From An Obsolete Logic Analyzer

October 7, 2022 by 15 Comments

The designers of older equipment that contained a CRT monitor rarely made the effort to design their own driver and deflection circuitry. Instead they were more likely to buy an off  the shelf assembly from a monitor manufacturer, and simply supply it with their video. [TomV] has an old HP 16500A logic analyzer, and in it he found a Sony monitor chassis. With a quest for a microfiche service manual and a bit of reverse engineering, he was able to hook it up to a VGA port and use it as an extension monitor for his laptop.

The monitor chassis is a Sony CHM-9001-00, which sports their 10″ Trinitron tube. These were among the very best CRT tubes of the day, making it the type of module 1990s hacker would have been very pleased to get their hands on. Here in 2022 a look at the monitor’s 40-pin connector reveals a standard RGB interface which the service manual confirms is within the voltage range to be driven from a VGA output. A Thinkpad X220 is pressed into service, with a 576 by 360 pixel at 60 Hz video mode defined, and there we have it, a modern desktop on an obsolete piece of test equipment.

The intended destination for this monitor is a small arcade cabinet, so it needed to be independent of the HP chassis. The required 120 VDC supply comes from an inverter designed for solar battery charging, which balked at the inrush current from the monitor when fed with 12 V. Increasing the supply voltage on the low voltage side solved that, leading to a very serviceable monitor. We have no use for one, but we’d be lying if we said we didn’t want one.

Perhaps you may have wondered, what made Trinitrons so good?

Building A Digital Library Of Amateur Radio And Communications

October 6, 2022 by 8 Comments

For years the Internet Archive has provided the online community with a breathtaking collection of resources, out of print books, magazines, recordings, software, and any other imaginable digital asset in easily retrievable form. Now with the help of a grant from the Amateur Radio Digital Communications Foundation they are seeking to create a collection that documents amateur radio from its earliest days to the present.

The work will be multi-faceted, and include the print and digital materials we’d expect, as well as personal archives and oral histories from notable radio amateurs. For many of us this will provide a wealth of technical details and insights into taming the ionosphere, but for future historians it will be an invaluable reference on the first century of the hobby.

Amateur radio is perhaps the oldest hardware hacking pursuit of the electronic age, because certainly at the start, radio was electronics. Thus amateur radio’s long history has indirectly given us many of the things we take for granted today. Sure it has its moribund aspects, but we think if it continues to follow the growth of new technology as it has for so many years it will continue to be an exciting pursuit. We look forward to browsing this archive, and we hope to see it grow over the years.

Header image: Lescarboura, Austin C. (Austin Celestin), 1891-, No restrictions.

Retro Speaker Becomes The Perfect Micro PC

October 5, 2022 by 6 Comments

We’ve seen many cyberdecks and home built computers in our time here at Hackaday, but we’ve not seen many so tiny and so neatly built as this one from [Carter Hurd]. It takes the form of a tiny retro PC with a working display and keyboard, and we like it a lot.

The diminutive computer started life as a neat little retro themed Bluetooth speaker that a company bravely sent him for a project when he declined the chance to review it. Out came the speaker and electronics, and in went a USB Blackberry keyboard with a custom made bezel where the speaker’s keys had been.

The display is a 4″ LCD designed for a Raspberry Pi, and somewhat incredibly, he trimmed its corners to fit into the case. Making the curved CRT-style display front was achieved with vacuum form plastic, and a new display bezel was 3D printed.

A full-size Raspberry Pi fits in the base of the unit, and here he admits that it’s not the tidiest job. Perhaps a Pi Zero would have been more unobtrusive, but either way from the top and front it’s a really cute little machine. It may not be the only tiny cyberdeck we’ve seen, but it’s certainly a well-built one.

Continue reading “Retro Speaker Becomes The Perfect Micro PC” →

The State Of The SBC Interface Ecosystem, Is It Time To Design A Standard?

October 5, 2022 by 132 Comments

We are spoiled for choice when it comes to single board computers, whether they be based around a microcontroller or a more capable SoC capable of running an operating system such as GNU/Linux. They can be had from well-established brands such as Arduino, Adafruit, or Raspberry Pi, or from a Wild West of cheaper Far Eastern modules carrying a plethora of different architectures.

Everyone has their own favourite among them, and along with that comes an ecosystem of operating systems and software development environments. There’s another aspect to these boards which has evolved; certain among them have become de facto interface connector standards for hardware peripherals. Do these standards make any sense? Let’s talk about that.

Continue reading “The State Of The SBC Interface Ecosystem, Is It Time To Design A Standard?” →