A man in a dark shirt stands at a podium in front of a projector screen with the text "50% OF US CAR TRIPS" in white above yellow text saying "1 HUMAN < 3 MILES". The screen is flanked by decor saying "Supercon" in white on a black background.

Supercon 2022: Bradley Gawthrop Wants You To Join The PEV Revolution

July 3, 2023 by Navarre Bartz 70 Comments

During the 20th Century, much of the western world decided that motor vehicles were the only desirable form of transportation. We built our cities to accommodate cars through parking, stop lights, and any number of other infrastructure investments so that you could go get milk and bread in style. In the US, 50% of automobile trips are less than three miles and have only one occupant. [Bradley Gawthrop] asked if there might be a more efficient way to do all this? Enter the Personal Electric Vehicle (PEV).

What Are PEVs?

PEVs are a nascent part of the transportation mix that fall under the wider umbrella of “micromobility,” including scooters, bikes, skateboards, and the like. The key differentiator here is that they are at least partially electrically-driven. [Gawthrop] walks us through several of the different types during his Supercon 2022 talk, but since they are all small, electric powered devices for transporting one or two people, they can trace their lineage back to the infamous Segway Human Transporter.

Using an electric motor or two connected to a controller and batteries, the overall system complexity for any of these devices is quite low and ripe for the hacking. Given the right tools and safety precautions, anyone should be able to crack a PEV open and repair or tinker with it. As with many things in life, the real story is more complicated.

As [Gawthrop] notes, many a hacker has said, “I wish I’d been able to be involved in X before…” where X equals some technology like home automation and it’s before it got creepy or dystopian in some manner. He exhorts us that the time to be in on the ground floor with PEVs is now. Continue reading “Supercon 2022: Bradley Gawthrop Wants You To Join The PEV Revolution” →

3D Printing Food Hack Chat

July 3, 2023 by Dan Maloney 1 Comment

Join us on Wednesday, July 5 at noon Pacific for the 3D Printing Food Hack Chat with Ellie Weinstein!

In the right hands, food goes beyond mere sustenance and becomes a work of art. We’ve all seen examples — the carefully crafted blends of flavors, the quality ingredients expertly cooked, the artful platings that make a dramatic presentation at the table. But where the artistry really seems to take off is with desserts, which pastry chefs and confectioners can take to the next level with edible sculptures of chocolate and other sweets that can tower dramatically over the table.

That’s all well and good for the haute cuisine set, but what about the rest of us? We can’t all have the talent and drive needed to produce edible art, so perhaps we can leverage technology to help us out. That’s just one of the rationales behind food 3D printing, which is what we’ll be exploring with Ellie Weinstein. She’s the CEO of Cocoa Press, where they’re bringing chocolate 3D printing to the mainstream. It’s not as easy as you might think — there are plenty of nuances and engineering challenges when you’re trying to print chocolate or any other kind of food. Make sure you stop by and check it out; it’s sure to be a treat.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, July 5 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

A Commodore 128 with a video capture device attached

Hacking The Commodore 128 To Capture Almost Real-Time Video

July 3, 2023 by Robin Kearey 10 Comments

Although watching and editing videos may be among the primary tasks of many PCs today, it wasn’t that long ago that working with video required powerful processors and expensive video capture hardware. Even in the 1980s, home computer users were looking for ways to connect video sources to their Commodores and Ataris despite their hardware limitations. [Cameron Kaiser] has a mid-1980s consumer-grade video capture device, which he has managed to turn into an almost real-time video capture system.

A distorted video image on a C128's monitor — Allowing the graphics chip to interrupt the CPU mid-capture results in a severely distorted image

His work revolves around a device called “ComputerEyes”, a 1984-vintage hardware interface that made it possible to connect a composite video source to a home computer. The limitations of mid-1980s CPUs meant that it took around six seconds for the computer to do a quick scan of a single video frame, or a multiple of that if you wanted a higher-quality image. Another limitation, at least on Commodore machines, was that the screen had to be turned off during video capture – otherwise, the video chip would interrupt the CPU halfway through the process, causing it to lose its synchronization with the video source.

[Cameron] however, plugged his ComputerEyes into a Commodore 128. This machine, largely designed by Hackaday contributor [Bil Herd], has an unusual hardware architecture consisting of two different CPUs and, crucially, two separate video chips. The primary 8564 “VIC-II” graphics chip is used to keep compatibility with existing Commodore 64 programs, while the secondary 8563 “VDC” is mainly aimed at newer high-resolution text-based software. The VDC is also much more independent from the main system bus than the VIC-II, allowing it to display an image without disturbing the CPU.

More after the break.

Continue reading “Hacking The Commodore 128 To Capture Almost Real-Time Video” →

Ice Wrenchers, Wrencher Chocolates, And The Vaquform DT2

July 3, 2023 by Jenny List 9 Comments

What do you do when you find some friends have bought a vacuum forming machine? Make novelty chocolates and ice cubes, of course! This was my response when I had the opportunity to play with a Vaquform DT2 all-in-one vacuum forming machine, so what follows is partly a short review of an exciting machine, and partly an account of my adventures in edible merchandise creation.

The vaquform machine, on a neutral white background — The Vaquform machine in all its glory.

Vacuum forming, the practice of drawing a sheet of heat-softened plastic film over a model to make a plastic shell copy of it, is nothing new in our community. It’s most often found in hackerspaces in the form of home made vacuum forming tables, and usually requires quite a bit of experimentation to get good results. The Vaquform machine I was lucky enough to be able to try is an all in one machine that puts the whole process into a compact desktop machine of similar size to a typical 3D printer. It’s a machine of two parts with a moveable carriage between them for the plastic sheet; a vacuum table on its base, and a heater unit suspended above it. The unique selling point is that it’s an all-in-one computer controlled unit that does as much as possible for you, it simply requires the user to place a sheet in the carriage and follow the instructions.

When I first saw the machine I didn’t really have anything to try it with, so of course I resorted to producing a Wrencher or two. Because what it makes are essentially moulds, it made sense to produce something Wrencher-shaped with them, and thus the chocolate and ice plan formed. The first mould was made with laser-cut Wrenchers in 2mm acrylic, stacked on two more layers of uncut acrylic to make a bar with an inset Wrencher on top, while the second one used a 3D-printed array of larger stand-alone Wrenchers with channels between them. Would my first attempt at vacuum forming make usable moulds or not? Only one way to find out. Continue reading “Ice Wrenchers, Wrencher Chocolates, And The Vaquform DT2” →

Four jumper wires with white heatshrink on them, labelled VCC, SCL, SDA and GND

Three Pitfalls In I2C Everyone Wishes Weren’t There

July 3, 2023 by Maya Posch 95 Comments

The best part of I2C is that it is a bus that is available just about anywhere, covering a vast ecosystem of devices that offer it as a hardware-defined interface, while being uncomplicated enough that it can also be implemented purely in software on plain GPIO pins. Despite this popularity, I2C is one of those famous informal standards that feature a couple of popular implementations, while leaving many of the details such as exact timing, bus capacitance and other tedious details to the poor sod doing the product development. Thus it is that we end up with articles such as a recent one on the tongue-twisting [pair of pared pears] blog, covering issues found while implementing an I2C slave.

As with any shared bus, whether multi-master or not, figuring out when the bus is clear is a fun topic, yet one which can cause endless headaches. One issue here comes from a feature that the SMBus version of I2C calls quick read/write. This allows for the rapid transfer of some data. Still, depending on the data returned by the slave, it may appear to the master that nothing is happening yet, since SDA is being held low by the slave until the stop condition, essentially locking the bus.

Where things get even more exciting comes generally in the form of what logic analyzers love to traumatically call a ‘spurious start/stop condition’. This refers to the behavior of SDA and SCL, with SDA going low before SCL indicating an error. This can occur due to a hold time that’s too low, causing other devices on the bus to miss the transition. Here SMBus defines a transition time of 300 ns, while I2C calls for 0 seconds, but it’s now suggested to delay calling a start/stop condition until a delay of 300 ns has passed. Essentially, it would seem that implementing a hold time is the way forward until evidence to the contrary appears.

The third pitfall pertains to the higher-speed modes of I2C, including Fast-Mode (FM) and Fast-Mode Plus (FM+). Backward compatibility with these higher speed versions is absent to spotty. Although FM+ (introduced by NXP in 2007) is supposed to be backward compatible with slower speeds, effectively the timing requirement differences between the FM+ and FM standards are too large to compensate for. At least in the current versions of the standards, but one of the joys of I2C is that there’s always another new set of revisions to look forward to.

Freq Out With LTSpice

July 3, 2023 by Al Williams 4 Comments

We always enjoy [FesZ’s] videos, and his latest about FREQ function in LTSpice is no exception. In fact, LTSpice doesn’t document it, but it is part of the underlying Spice system. So, of course, you can figure it out or just watch the video below. The FREQ keyword allows you to change component attributes in a frequency-depended way.

Of course, capacitors and inductors are frequency dependent by design. But the FREQ technique allows you to adjust things like voltage sources or resistance in arbitrary ways. By default, you must specify the frequency response data in decibels, which isn’t always convenient. However, [FesZ] shows you how to use other methods to express them using modifiers to the command.

Continue reading “Freq Out With LTSpice” →

Presence Sensor Locks Computer When You Step Away

July 2, 2023 by Bryan Cockfield 14 Comments

Having a computer that locks its screen after a few minutes of inactivity is always a good idea from a security standpoint, especially in offices where there is a lot of foot traffic. Even the five- or ten-minute activity timers that are set on most workstations aren’t really perfect solutions. While ideally in these situations we’d all be locking our screens manually when we get up, that doesn’t always happen. The only way to guarantee that this problem is solved is to use something like this automatic workstation locker.

The project is based around the LD2410 presence sensor — a small 24 GHz radar module featuring onboard signal processing which simplifies the detection of objects and motion. [Enzo] paired one of these modules with a Seeed Studio XIAO nRF52840 development board to listen to the radar module and send the screen lock keyboard shortcut to the computer when it detects that the user has walked away from the machine. The only thing that [Enzo] wants to add is a blinking LED to let the user know when the device is about to timeout so that it doesn’t accidentally lock the machine when not needed.

One of the parts of this build that is a little bit glossed over is the fact that plenty of microcontroller platforms can send keystrokes to a computer even if they’re not themselves a USB keyboard. Even the Arduino Uno can do this, so by now this feature is fairly platform-agnostic. Still, you can use this to your advantage if you have the opposite problem from [Enzo] and need your computer to stay logged in no matter what.