Motorcycle Rally Computer Goes Open Source

November 11, 2021 by Adam Zeloof 6 Comments

Motorcycle rally racing is a high-speed, exciting, off-road motorsport that involves zipping across all types of terrain on two wheels. While riding, it’s extremely important for riders to know what’s coming up next — turns, straightaways, stream crossings, the list goes on. Generally, this is handled by a roadbook — a paper scroll that has diagrams of each turn or course checkpoint, along with the distances between them and any other pertinent information. Of course, this needs to be paired with a readout that tells you how far you’ve traveled since the last waypoint so you’re not just guessing. This readout usually takes the form of a rally computer, a device that can display speed, distance traveled, and course heading (and some of the fancier ones have even more data available).

A roadbook with commercially-available rally computers

Frustrated with the lackluster interface and high cost associated with most rally computers on the market, [Matias Godoy] designed his own back in 2017, and was quick to realize he had a potential product. After several iterations he brought his idea to market with a small initial run, which sold out in a few hours!

He then took some time to reflect on the successful campaign. He decided that rather than continue to churn out units, he would open-source the design to make it available to everybody and see what the community could come up with. He published all of his design files to GitHub, and wrote up a wonderful blog post documenting the entire design process, from inspiration and early prototypes to his decision to go open source.

[Matias]’s project, the Open Rally Computer (formerly the Baja Pro) packages neatly in a CNC-machined case and features a nice high-visibility LCD display, a built-in GPS receiver, and an ergonomic handlebar-mounted remote. The data is crunched by an ESP32 microcontroller, which also allows for WiFi-enabled OTA updates. The end result is a beautiful and useful device that was clearly designed with great care. Love the idea but not a rally racer? If street bikes are more your thing then fear not because there’s an open source digital dashboard out there for you too.

[Nick Rehm] explains the workings of a gps-less self guided drone

Autonomous Drone Dodges Obstacles Without GPS

November 3, 2021 by Ryan Flowers 5 Comments

If you’re [Nick Rehm], you want a drone that can plan its own routes even at low altitudes with unplanned obstacles blocking its way. (Video, embedded below.) And or course, you build it from scratch.

Why? Getting a drone that can fly a path and even return home when the battery is low, signal is lost, or on command, is simple enough. Just go to your favorite retailer, search “gps drone” and you can get away for a shockingly low dollar amount. This is possible because GPS receivers have become cheap, small, light, and power efficient. While all of these inexpensive drones can fly a predetermined path, they usually do so by flying over any obstacles rather than around.

[Nick Rehm] has envisioned a quadcopter that can do all of the things a GPS-enabled drone can do, without the use of a GPS receiver. [Nick] makes this possible by using algorithms similar to those used by Google Maps, with data coming from a typical IMU, a camera for Computer Vision, LIDAR for altitude, and an Intel RealSense camera for detection of position and movement. A Raspberry Pi 4 running Robot Operating System runs the autonomous show, and a Teensy takes care of flight control duties.

What we really enjoy about [Nick]’s video is his clear presentation of complex technologies, and a great sense of humor about a project that has consumed untold amounts of time, patience, and duct tape.

We can’t help but wonder if DARPA will allow [Nick] to fly his drone in the Subterranean Challenge such as the one hosted in an unfinished nuclear power plant in 2020.

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Omni-Wheeled Cane Steers The Visually-Impaired Away From Obstacles

October 24, 2021 by Kristina Panos 21 Comments

Sure, there are smart canes out there, commercial and otherwise. We’ve seen more than a few over the years. But a group of students at Stanford University have managed to bring something novel to the augmented cane.

Theirs features a motorized omni wheel that sweeps smoothly from left to right during normal cane operation, and when the cane senses an object that turns out to be an obstacle, the omni wheel goes into active mode, pulling the user out of the path of danger.

Tied for best part of this build is the fact that they made the project with open hardware and published all the gory details in a repo, so anyone can replicate it for about $400.

The cane uses a Raspi 4 with camera to detect objects, and a 2-D LIDAR to measure the distance to those objects. There’s a GPS and a 9-DOF IMU to find the position and orientation of the user. Their paper is open, too, and it comes with a BOM and build instructions. Be sure to check it out in action after the break.

There’s more than one way to guide people around with haptic feedback. Here’s the smartest pair of shoes we’ve seen lately.

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GPS? With Starlink, We Don’t Need It Any More!

October 10, 2021 by Jenny List 58 Comments

To find your position on the earth’s surface there are a variety of satellite-based navigation systems in orbit above us, and many receiver chipsets found in mobile phones and the like can use more than one of them. Should you not wish to be tied to a system produced by a national government though, there’s now an alternative. It comes not from an official source though, but as a side-effect of something else. Researchers at Ohio State University have used the Starlink satellite broadband constellation to derive positional fixing, achieving a claimed 8-metre accuracy.

The press release is light on information about the algorithm used, but since it mentions that it relies on having advance knowledge of the position and speed of each satellite we’re guessing that it measures the Doppler shift of each satellite’s signal during a pass to determine a relative position which can be refined by subsequent observations of other Starlink craft.

The most interesting takeaway is that while this technique leverages the Starlink network, it doesn’t have any connection to the service itself. Instead it’s an entirely passive use of the satellites, and though its accuracy is around an order of magnitude less than that achievable under GPS it delivers a position fix still useful enough to fit the purposes of plenty of users.

Earlier in the year there was some amusement when the British government bought a satellite broadband company under the reported impression it could plug the gap left by their withdrawal from the European Galileo project. Given this revelation, maybe they were onto something after all!

Thanks [Renze] for the tip.

MicroGPS Sees What You Overlook

October 7, 2021 by Matthew Carlson 45 Comments

GPS is an incredibly powerful tool that allows devices such as your smartphone to know roughly where they are with an accuracy of around a meter in some cases. However, this is largely too inaccurate for many use cases and that accuracy drops considerably when inside such as warehouse robots that rely on barcodes on the floor. In response, researchers [Linguang Zhang, Adam Finkelstein, Szymon Rusinkiewicz] at Princeton have developed a system they refer to as MicroGPS that uses pictures of the ground to determine its location with sub-centimeter accuracy.

The system has a downward-facing monochrome camera with a light shield to control for exposure. Camera output feeds into an Nvidia Jetson TX1 platform for processing. The idea is actually quite similar to that of an optical mouse as they are often little more than a downward-facing low-resolution camera with some clever processing. Rather than trying to capture relative position like a mouse, the researchers are trying to capture absolute position. Imagine picking up your mouse, dropping it on a different spot on your mousepad, and having the cursor snap to a different part of the screen. To our eyes that are quite far away from the surface, asphalt, tarmac, concrete, and carpet look quite uniform. But to a macro camera, there are cracks, fibers, and imperfections that are distinct and recognizable.

They sample the surface ahead of time, creating a globally consistent map of all the images stitched together. Then while moving around, they extract features and implement a voting method to filter out numerous false positives. The system is robust enough to work even a month after the initial dataset was created on an outside road. They put leaves on the ground to try and fool the system but saw remarkably stable navigation.

Their paper, code, and dataset are all available online. We’re looking forward to fusion systems where it can combine GPS, Wifi triangulation, and MicroGPS to provide a robust and accurate position.

Video after the break.

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Captivating Clock Puts Endangered Displays On Display

September 24, 2021 by Ryan Flowers 18 Comments

The DT-1704A VFD is straight from the 1976 Radio Shack Catalog — The DT-1704 VFD as seen the 1976 Radio Shack Catalog. The “A” version has no substrate, making the VFD fully clear for added effect.

When you have a small stock of vacuum fluorescent displays (VFDs) straight out of the 1976 Radio Shack catalog, you might sit around wondering what to do with them. When [stepawayfromthegirls] found out that his stash of seven DT-1704A tubes may be the last in existence, there was no question. They must be displayed! [stepawayfromthegirls]’ mode of display is this captivating clock build. Four VFDs with their aqua colored elements are set against a black background in a bespoke wooden case. Looking under the hood, the beauty only increases.

VFD Clock Wiring is almost as stunning as the clock itself — VFD Clock Wiring is nearly as stunning as the clock itself.

Keeping the build organized was not an easy task because the tubes are designed in such a way that each segment must be individually controlled. The needed I/O duties are provided by an Arduino Mega 2560 Pro (Embed). 28 2n3904’s each with their two resistors serve as drivers for each VFD segment.

The output of a 24 V AC transformer left over from the 1980s is rectified to 34 V of DC power which is then regulated to 27 V to power the tubes. Switching power supplies provide 6 V to the Arduino and 1.3 V to the filaments. If you look closely, you’ll also see a GPS module so that the clock doesn’t need to be set. To future-proof the clock against daylight savings time adjustments, a potentiometer on the back of the case allows the user to set custom hour offsets without editing any code.

We think the end result is a remarkably clean, simple, and elegant clock that he will be proud of for many years to come!

If VFD clock builds are your thing, then you’ll enjoy this Network Attached VFD Clock and a Mini VFD Clock with floating display. And while not VFD based, we’d be silly to leave out the Boat Anchor Nixie Clock with enough knobs, switches, and buttons to delight even the fussiest of hacker.

Homebrew Sounder Maps The Depths In Depth

September 6, 2021 by Dan Maloney 10 Comments

For those who like to muck around in boats, there’s enough to worry about without wondering if you’re going to run aground. And there’s really no way to know that other than to work from charts that show you exactly what lies beneath. But what does one do for places where no such charts exist? Easy — make your own homebrew water depth logger.

Thankfully, gone are the days when an able seaman would manually deploy the sounding line and call out the depth to the bottom. [Neumi]’s sounding rig uses an off-the-shelf sonar depth sounder, one with NMEA, or National Marine Electronic Association, output. Combined with a GPS module and an Arduino with an SD card, the rig can keep track not only of how much water is below it, but exactly where the measurement point is. The whole thing is rigged up to an inflatable dinghy which lets it slowly ply the confines of a small marina, working in and out of the nooks and crannies. A bit of Python and matplotlib stitches that data together into a bathymetric map of the harbor, with pretty fine detail. The chart also takes the tides into account, as the water level varies quite a bit over the four hours it takes to gather all the data. See it in action in the video after the hop.

There’s something cool about revealing the mysteries of the deep, even if they’re not that deep. Want to go a little deeper? We’ve seen that before too.

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