This Bike Sonar is Off the Chain

On paper, bicycling is an excellent form of transportation. Not only are there some obvious health benefits, the impact on the environment is much less than anything not directly powered by a human. But let’s face it: riding a bike can be quite scary in practice, especially along the same roads as cars and trucks. It’s hard to analyze the possible threats looming behind you without a pair of eyes in the back of your head.

radar-sweep-display[Claire Chen] and [Mark Zhao] have come up with the next best thing—bike sonar. It’s a two-part system that takes information from an ultrasonic rangefinder and uses it to create sound-localized pings in a rider’s ears. The rangefinder is attached to a servo mounted on the seat post. It sweeps back and forth to detect objects within 4 meters, and this information is displayed radar-sweep-style graphic on a TFT screen via a PIC32.

Though the graphic display looks awesome, it’s slow feedback and a bit dangerous to have to look down all the time — the audio feedback is by far the most useful. The bike-side circuits sends angle and distance data over 2.4GHz to another PIC mounted on a helmet. This PIC uses sound localization to create a ping noise that matches the distance and location of whatever is on your tail. The ping volume is relative to the distance of the object, and you just plug headphones into the audio jack to hear them. Bunny-hop your way past the break to check it out.

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Why the Wright Brothers Succeeded

The types of steps and missteps the Wright brothers took in developing the first practical airplane should be familiar to hackers. They started with a simple kite design and painstakingly added only a few features at a time, testing each, and discarding some. The airfoil data they had was wrong and they had to make their own wind tunnel to produce their own data. Unable to find motor manufacturers willing to do a one-off to their specifications, they had to make their own.

Sound familiar? Here’s a trip through the Wright brothers development of the first practical airplane.

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Tracking Planes with an ESP8266

While there are apps that will display plane locations, [squix78] wanted to build a dedicated device for plane spotting. The ESP8266 PlaneSpotter Color is a standalone device that displays a live map with plane data on a color TFT screen. This device expands on his PlaneSpotter project, adding a color display and mapping functions.

First up, the device needs to know where planes are. The ADS-B data that is transmitted from planes contains useful data including altitude, velocity, position, and an identifier unique to the aircraft. While commercial services exist for getting this data, the PlaneSpotter uses ADS-B Exchange. You can set up a Raspberry Pi to record this data, and provide it to ADS-B Exchange.

With the plane data being received from the ADS-B Exchange API, it’s time to draw to the screen. The JPEGDecoder fork for ESP8266 is used for drawing images, which are fetched from the MapQuest API as JPEGs.

Finally, geolocation is needed to determine where in the world the PlaneSpotter is. Rather than adding a GPS module, [squix78] went with a cheap solution: WiFi geolocation. This uses identifying information and signal strengths from nearby WiFi access points to determine location. This project uses a public API by [Alexander Mylnikov], which returns a JSON object with longitude and latitude.

This project demonstrates what the ESP8266 is capable of, and brings together some neat techniques. If you’re looking to geolocate or display maps on an ESP8266, the code is available on Github.

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Another Electric Longboard Goes the Distance

Looks like electric longboards are becoming a thing, with increasingly complex electronics going into them to squeeze as much performance as possible out of them. When an electric longboard lasts for 35 miles, can longboard hypermiling be far behind?

If endurance longboarding sounds familiar, it’s because we just covered a 25-mile electric that outlasted its rider. To get the extra 10 miles, [Andrew] cheated a little, with a backpack full of extra batteries powering his modified Boosted Board, a commercially available electric longboard. But the backpack battery was only a prototype, and now [Andrew] is well on his way to moving those batteries to a custom underslung enclosure on his new “Voyager” board. Eschewing balancing and monitoring circuitry in favor of getting as many batteries on board as possible, [Andrew] managed sixty 18650s in a 10S6P configuration for 37 volts at 21 Ah. He didn’t scrimp on tools, though – a commercial terminal welder connects all the battery contacts. We really like the overall fit and finish and the attention to detail; an O-ring seal on the 3D-printed enclosure is a smart choice.

Voyager isn’t quite roadworthy yet, so we hope we’ll get an update and perhaps a video when [Andrew] goes for another record.

Long-range Electric Longboard Outlasts Rider

What could be better than a holiday ride past the palm trees and blue waters of a Mediterranean resort town? Perhaps making that ride on a long-range electric longboard of your own design will ice that particular cake.

And when we say long range, we mean it – an estimated 25 miles. The only reason [overclocker_kris] couldn’t come up with an exact number in the test drive seen below is that he got too tired to continue after mile 20. With a bit of juice left in the 64-cell battery pack, built from 18650s harvested from old laptops, the board was sure to have another five miles in it. A custom molded underslung carbon fiber enclosure houses the battery pack and electronics, including the receiver for the handheld remote control and the ESCs for the two motors. Motor mounts were fabbed from aluminum and welded to the trucks, with power transmission through timing belts to 3D-printed pulleys. It’s a good-looking build, and topping out at 22 MPH isn’t too shabby either.

We’ve covered fleets of electric longboards before, from those with entirely 3D-printed decks to one with a flexible battery pack. But we doubt any have the endurance and performance of this board.

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Cheap Electric Car Drives Again with Charger Repair

If someone sent you an advert for an electric car with a price too low to pass up, what would you do? [Leadacid44] was in that lucky situation, and since it was crazy cheap, bought the car.

Of course, there’s always a problem of some kind with any cheap car, and this one was no exception. In this case, making it ‘go’ for any reasonable distance was the problem. Eventually a faulty battery charging system was diagnosed and fixed, but not before chasing down a few other possibilities. While the eventual solution was a relatively simple one the write-up of the car and the process of finding it makes for an interesting read.

The car in question is a ZENN, a Canadian-made and electric-powered licensed version of the French Microcar MC2 low-speed city car with a 72 volt lead-acid battery pack that gives a range of about 40 miles and a limited top speed of 25 miles per hour. Not a vehicle that is an uncommon sight in European cities, but very rare indeed in North America. Through the write-up we are introduced to this unusual vehicle, the choice of battery packs, and to the charger that turned out to be defective. We’re then shown the common fault with these units, a familiar dry joint issue from poor quality lead-free solder, and taken through the repair.

We are so used to lithium-ion batteries in electric cars that it’s easy to forget there is still a small niche for lead-acid in transportation. Short-range vehicles like this one or many of the current crop of electric UTVs can do without the capacity and weight savings, and reap the benefit of the older technology being significantly cheaper. It would however be fascinating to see what the ZENN could achieve with a lithium-ion pack and the removal of that speed limiter.

If your curiosity is whetted by European electric microcars, take a look at our previous feature n the futuristic Hotzenblitz, from Germany.

Jumper Cables Block Trains

Standing Rock, North Dakota has been the site of a major protest this year against the Dakota Access Pipeline project. Protesters have sought to delay the pipeline’s progress by a wide variety of means, and both sides in the conflict have been accused of a variety of misdeeds.

An anonymous group supporting the protesters has released a video describing how they stop trains without the use of physical barricades. The video begins with police removing automobiles used to block the tracks and escorting trains through level crossings, showing how these traditional methods have been ineffective.

The video then goes on to outline what is described as a “sneaky” way of halting trains. Most railroads use what is known as a track circuit — a current run through the rails of the track detects when a train passes over it by the axles completing an electrical circuit between the two. By using a standard automotive jumper cable to connect the two rails together instead, the circuit is completed and falsely indicates to the railway signalling system that a train is present on the track in question. Due to the safety-critical nature of the railway, no trains can be run on the track until the short circuit is removed, else there is a great risk of collisions between trains on the network.

Intended as a practical guide, strategies to maximize disruption are outlined, such as hiding the cables under snow and painting them in black to evade detection as long as possible. Instructions on how to best make a solid connection to the rails are also shared.

It goes without saying that interfering with major infrastructure is risky, dangerous, and highly illegal. Protesters have already been arrested for physically blocking trains. Perpetrators of this method will surely be arrested if caught, and circumventing the technology could easily result in harsher charges associated with electronic security and safety systems. This is sabotage (deliberately obstructing) and undermines the validity of peaceful protest.

This shows how ingenuity is often spawned by turmoil and frustration. Reflect on human nature, and catch the video below the break.

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