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Hackaday Links: August 18, 2024

They’re back! The San Francisco autonomous vehicle hijinks, that is, as Waymo’s fleet of driverless cars recently took up the fun new hobby of honking their horns in the wee hours of the morning. Meat-based neighbors of a Waymo parking lot in the South Market neighborhood took offense at the fleet of autonomous vehicles sounding off at 4:00 AM as they shuffled themselves around in the parking lot in a slow-motion ballet of undetermined purpose. The horn-honking is apparently by design, as the cars are programmed to tootle their horn trumpets melodiously if they detect another vehicle backing up into them. That’s understandable; we’ve tootled ourselves under these conditions, with vigor, even. But when the parking lot is full of cars that (presumably) can’t hear the honking and (also presumably) know where the other driverless vehicles are as well as their intent, what’s the point? Luckily, Waymo is on the case, as they issued a fix to keep the peace. Unfortunately, it sounds like the fix is just to geofence the lot and inhibit honking there, which seems like just a band-aid to us.

Continue reading “Hackaday Links: August 18, 2024”

BikeBeamer Adds POV Display To Bicycle Wheels

Unless you’re living in a bicycle paradise like the Netherlands, most people will choose to add some sort of illumination to their bicycle to help drivers take note that there’s something other than a car using the road. Generally, simple flashing LEDs for both the front and the rear is a pretty good start, but it doesn’t hurt to add a few more lights to the bicycle or increase their brightness. On the other hand, if you want to add some style to your bicycle lighting system then this persistence of vision (POV) display called the BikeBeamer from [locxter] might be just the thing.

The display uses four LED strips, each housed in their own 3D printed case which are installed at 90-degree angles from one another in between the spokes of a standard bicycle wheel. An ESP32 sits at the base of one of the strips and is responsible for storing the image and directing the four displays. This is a little more complex than a standard POV display as it’s also capable of keeping up with the changing rotational speeds of the bicycle wheels when in use. The design also incorporates batteries so that no wires need to route from the bike frame to the spinning wheels.

This is an ongoing project for [locxter] as well, meaning that there are some planned upgrades even to this model that should be in the pipe for the future. Improving the efficiency of the code will hopefully allow for more complex images and even animations to be displayed in the future, and there are also some plans to improve the PCB as well with all surface-mount components. There are a few other ways to upgrade your bike’s lighting as well, and we could recommend this heads-up headlight display to get started.

Running Power And Data Over Just Two Wires

When you’re hooking up equipment across a vehicle, you’re often stuck sending power and data to and from things like sensors or actuators. The more wires you have to run, the more hassle, so it’s desirable to get this number as low as possible. That’s an especially big deal in the world of cycling electronics, where every additional gram is considered a drawback. To this end, companies have developed two-wire methods of sending power and data together, and now, [Keith Wakeham] has devised his own way of doing so.

[Keith] was inspired by Shimano’s E-Tube system which is fairly fancy in its encoding schemes, but he went his own way. His concept relied on old-school On-Off Keying methods to take a signal and capacitively couple a signal into power lines. He explains the theory behind the method, and shares schematics that can be used to actually communicate over power lines. Then, he shows off the real hardware that he built to test the concept for himself.

The results? Good! [Keith] was able to maintain speeds of 57,600 bits/second even with an electrically-noisy gear motor operating on the lines. That’s more then enough for all kinds of applications.

If you’ve got your own data-over-powerline hacks, don’t hesitate to let us know. Continue reading “Running Power And Data Over Just Two Wires”

Digital Bike Horn Will Play Custom Sounds, Please Be Tasteful

When you’re out riding your bike, a horn can be a useful warning device to other road users and pedestrians alike. It can also be a source of fun and amusement, or annoyance, depending on the sounds it makes and how you use it. For the ultimate flexibility, you might like this digital bicycle horn that offers customizable sounds, as developed by [gokux].

The build has attractive two-tone components, consisting of a button pad for playing four sounds, and a sound module with a 3 watt speaker and battery pack. A Seeed Studio XIAO SAMD21 is the heart of the operation, with the microcontroller paired with a DFPlayer Mini which handles sound duties. When one of the four buttons is pressed, the microcontroller loads the relevant sound off an SD card, and plays it out over the speaker. For power, the build uses a lithium rechargeable battery with a healthy 1200 mAh capacity, which can be readily recharged thanks to a TP4056 charger module with a USB-C port.

It’s a nifty little build, and we love the Metal Gear Solid sounds. Though, we do wonder just how audible that 3 watt speaker is. If it proves inadequate, you could always step up to a much larger driver paired with a hefty audio amp if you so desire.

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An Open-Source Ebike Motor Controller

DIY e-bikes are often easy to spot. If they’re not built out of something insane like an old washing machine motor, the more subtle kits that are generally used still stand out when compared to a non-assisted bike. The motors tend to be hub- or mid-drive systems with visible wires leading to a bulky battery, all of which stand out when you know what to look for. To get a stealthy ebike that looks basically the same as a standard bicycle is only possible with proprietary name-brand solutions that don’t lend themselves to owner repair or modification, but this one has at least been adapted for use with an open source motor controller.

The bike in use here is a model called the Curt from Estonian ebike builder Ampler, which is notable in that it looks indistinguishable from a regular bicycle with the exception of the small 36-volt, 350-watt hub motor somewhat hidden in the rear wheel. [BB8] decided based on no reason in particular to replace the proprietary motor controller with one based on VESC, an open-source electric motor controller for all kinds of motors even beyond ebikes. Installed on a tiny Arduino, it fits inside the bike’s downtube to keep the stealthy look and can get the bike comfortably up to around 35 kph. It’s also been programmed to turn on the bike’s lights if the pedals are spun backwards, and this method is also used to change the pedal assist level, meaning less buttons and other user-interface devices on the handlebars. Continue reading “An Open-Source Ebike Motor Controller”

Two men in black shirts stand between a white and a blue exercise bike sitting on a table in front of them. The exercise bikes have black drums slightly larger than a coffee can affixed to the front of the bike which houses the shredding mechanism. In the background is a "Precious Plastics Torino" circular logo.

Getting Shredded Plastic…and Legs

While electric motors have taken the drudgery out of many tasks, human power has its advantages. [Precious Plastic Torino] has developed a human-powered plastic shredder for those times when an electric motor just won’t do.

Designed primarily for educational purposes at venues where electricity can be difficult to source, but also useful for off-grid environments, this exercise bike-based shredder can take small pieces of plastic and shred them into tiny pieces suitable for use with any of the other machines in the Precious Plastics ecosystem like their injection molding machine. As with all [Precious Plastics] projects, the files are will be open source; however, there is a six month exclusivity period for Patreon subscribers to help fund development efforts.

The build is relatively simple: take an old exercise bike, remove the unnecessary bits, and run the chain up to drive a shredding mechanism mounted on the front of the bike. We think they should’ve kept the flywheel to help keep the momentum going while shredding but can’t fault them for wanting to keep the prototype as simple as possible. Maybe the next step is getting these in spin classes around the country so people can get their exercise and help recycle in their community at the same time!

If this shredder doesn’t suit your fancy, maybe recycle your plastic with SHREDII or this other DIY effort. If you’d rather generate electricity on your exercise bike, then try building this bike generator.

Continue reading “Getting Shredded Plastic…and Legs”

A silver front loader cargo bike sits in a parking lot in front of an electric vehicle charger. A cable runs from the charger to the bike.

Fast Charging A Cargo Bike From An Electric Car Charger

Fast charging is all the rage with new electric cars touting faster and faster times to full, but other EVs like ebikes and scooters are often left out of the fun with exceedingly slow charging times. [eprotiva] wanted to change this, so he rigged up a fast charging solution for his cargo bike.

Level 2 electric vehicle chargers typically output power at 7 kW with the idea you will fill up your electric car overnight, but when converted down to 60 V DC for a DJI Agras T10 battery, [eprotiva] is able to charge from 20% to 100% capacity in as little as 7 minutes. He originally picked this setup for maxing the regen capability of the bike, but with the high current capability, he found it had the added bonus of fast charging.

The setup uses a Tesla (NACS) plug since they are the most plentiful destination charger, but an adapter allows him to also connect to a J1772 Type 1 connector. The EV charging cable is converted to a standard 240 V computer cable which feeds power to a drone charger. This charger can be set to “fast charge” and then feeds into the battery unit. As an added bonus, many chargers that do cost money don’t start charging until after the first five minutes, so the bike is even cheaper to power than you’d expect.

For some reason, you can watch him do this on TikTok too.

If you too want to join the Personal EV Revolution, be sure to checkout how to choose the right battery for your vehicle and a short history of the Segway.