SLAM Navigation For An Arduino Powered Car

There are plenty of “robot” projects out there that are really just a small remote control platform of some sort. We often like to think of robots of having some sort of autonomy though. [Luca Fagioli] demonstrates a great example of this with his explorer robot that uses Simultaneous Localization and Mapping (SLAM) to navigate its environment.

The robot is a built on a small plastic chassis, with one gear motor per drive wheel. Running the show is an Arduino Uno R4 Wi-Fi, paired with the Sensor Shield 5.0 and an L298N motor driver board. There’s also an HC-SR04 ultrasonic sensor module onboard, mounted atop an SG-90 servo motor so it can be panned around. The ultrasonic sensor determines the range between the robot and surrounding walls, and a map is constructed at the same time as the robot is localizing itself within it. There are also infrared sensors on the bottom of the robot for detecting tape marks on the floor for checkpointing purposes.

Often, SLAM mapping is done with advanced laser rangefinders or time of flight sensors, but there are many ways to go about it as this project demonstrates. We’ve even seen it done in a distributed manner with coordinated drones combining their efforts. Overall, it’s a highly useful technique for robot navigation and wayfinding.

Continue reading “SLAM Navigation For An Arduino Powered Car” →

Hacking A Marine Radio Dish

Having watched some fun videos on repurposed satellite dishes on YouTube, [Melan] wanted to get in on the action, managed to source an Intellian i4 — a dish built for marine use — and set about hacking it.

[Melan] first needed to convince the antenna that it was still on a boat by using an RP2040 microcontroller and an RS-422 module to send NMEA sentences. This was necessary to tell the i4 the “heading” of the “boat”, even though [Melan] was really using the rig stationary on land. From there, a simple email to the company itself sufficed to get the Intellian software running on the antenna.

But could it be controlled without the software?. Sniff the communications between the software and the Antenna Control Unit, and decompile the code. This done, it was relatively straightforward to put together a protocol description and figure out how to command the antenna where to point simply by issuing commands for azimuth and elevation.

We’ve featured other great bits of satellite equipment before, like this truck tracker teardown from a few years ago. If you’ve got some nice equipment on the bench that listens in on (or transmits out to) birds in space, don’t hesitate to let us know on the tipsline.

Airborne Particle Monitoring, The BIG Way

Airborne micro particles can be a significant health hazard in a workshop, and thus it’s important to maintain a high standard of ventilation. But monitoring their concentration is also important, and thus there exists a range of sensors to help keep you safe. [WeSpeakEnglish] has taken this idea to the MAX, with a PM2.5 sensor that drives a very large wall mounted display. You’ll never be uncertain what the level is now!

The standout feature of this thing is a huge addressable LED seven segment display PCB, upon the back of which sits a tiny Seeed Studio Xiao board to which the particle sensor is hooked up. The software displays the particle count, and handily changes the colour as the number creeps upwards. Meanwhile should you wish to log the readings, the USB exposes a serial port upon which they are placed.

We can see this is a useful project for anywhere that is likely to have a high particle count, but it’s worth noting also that a large 7-segment display with an ESP32 board attached could have plenty of other uses. Meanwhile this is a nicely finished air quality monitor, but it’s certainly not the first we’ve seen.

How A Single University Project Started Everything

If we care to cast an eye over the history of ubiquitous personal computing as we know it today, we might immediately point at the original IBM PC. After all, for most of us our machines share backward compatibility in some form through multiple generations back to that original box from 1981.

But if we look at the things we use today and take for granted, from laser printers to graphics cards to the routers which power most of the Internet, they’re not from IBM at all. At the recent Vintage Computing Festival Berlin, [Michael Engel] delivered a talk naming a surprising progenitor for much of that technology, none other than Sun Microsystems.

It all starts with [Andy Bechtolsheim], famously Sun’s co-founder, when at the end of the 1970s he was a postgraduate at Stanford University. Working on the Stanford University Network — SUN — project he designed a computer to be used as a workstation on the network. The processor of choice then was Motorola’s 68000, but it lacked the MMU that would be required to run UNIX. His design had an MMU implemented externally to the 68000, with a bank of SRAM serving as the page table. This design would form the CPU board of the first Sun workstation.

The story might end there, were it not that many other companies had the same requirement, and Sun could supply them a CPU board. Silicon Graphics, the distant ancestral progenitor of your GPU, was one of them, so the first SGI workstation also had the same CPU as the first Sun. It appeared in the early Imagen laser printers too, as well as commercial AppleTalk to Ethernet bridges. Perhaps the biggest surprise is that because the original Stanford board had also been used as a router, the software for that became part of Cisco’s first product.

The video is below the break, and it’s a fascinating watch.

Continue reading “How A Single University Project Started Everything” →

2026 Retrocomputing Challenge: Explore Space With A Credit Card Reader

The humble credit card reader — most of us have used hundreds, perhaps even thousands of them over the years. But even for folks like us, it’s not the sort of device we give a lot of thought to. It’s just a keypad, a display, and a magnetic stripe reader. How interesting could it possibly be?

That may be true in some cases, but at least for the 1990s-era TRANZ 330, there’s a bit more to the story than that. As [CharlesD] explains, these particular readers are essentially complete Z80 computers just waiting to do something more exciting than processing PINs. In the case of this particular unit, the addition of a GPS module and some new code has turned it into an interactive guide to the solar system.

Thanks to the UV erasable ROMs used in the TRANZ 330, loading new code on the device is easy enough. With a bit of educated poking around, [CharlesD] was able to map out what did what. Working from the basics of getting the display and keypad working, he moved onto the serial interface, which in turn let him communicate with a modern GPS module and era-appropriate thermal printer. From there it was just a matter of getting the math implemented to compute the azimuth and elevation of a given planet, and he had an offline map of the solar system for use with his telescope.

This is one of those projects which is awesome enough on its own merits, but it’s particularly exciting to see just how easy it is to repurpose one of these card readers, especially since [CharlesD] was kind enough to share his source code. If you end up picking one of these up and getting something running on it, be sure to let us know.

Where Did Your Mouse Come From?

Many readers will be familiar with Douglas Englebart’s 1968 so-called “Mother of All Demos”, in which he described many of the devices and technologies we would be using two or three decades later. Among these was a primitive computer mouse, but while famous it was by no means the earliest pointing device. At the recent Vintage Computer Festival Berlin, [Dmitriy Kostiuk] delivered a fascinating lecture of the history of the pointing device.

It’s a long video that we’ve placed below, and it’s an exhaustive examination of the topic from the earliest examples to the 1990s when mice became commoditized. It’s a surprise to find that the first pointing device was a trackball built for a 1950s Canadian warship, with a surprisingly modern-looking optical encoder. Englebart’s 1966 wooden block with its pair of wheels and potentiometers had a less-well-known and much more stylish competitor in the same year from Telefunken.

We visit the various design iterations as the form of what we’d call a mouse today took shape. It’s unexpected to find that those Sun mice with the spotty mouse pad weren’t from Sun at all, they were from Mouse Systems. The first mice from Microsoft and Apple make an appearance, as do some awful designs for 8-bit computrs. Remembering those in particular perhaps it’s as well we didn’t have the cash to buy such a disappointing product for ourselves.

The video is long, but interesting. Give it a watch.

Continue reading “Where Did Your Mouse Come From?” →

How Bad Is That Bridge: A Government Database

Bridges! We kind of expect them to just be there and do their job, ad infinitum. They are built into the landscape, and we often take them and the routes they open up for granted.

The reality, as any civil engineer will tell you, is that bridges are living, breathing things that require endless maintenance and monitoring to keep them safe, standing, and functional. A great example of this is found in the US Department of Transportation, and its publicly accessible register of bridge health reports.

Continue reading “How Bad Is That Bridge: A Government Database” →