Front view of blue bicycle with Raspberry Pi webserver

Pedaling Your Mobile Web Server Across The Globe

We tinkerers often have ideas we know are crazy, and we make them up in the most bizarre places, too. For example, just imagine hosting a website while pedaling across the world—who would (not) want that? Meet [Jelle Reith], a tinkerer on an epic cycling adventure, whose bicycle doubles as a mobile web server. [Jelle]’s project, jelle.bike, will from the 6th of December on showcase what he’s seeing in real time, powered by ingenuity and his hub dynamo. If you read this far, you’ll probably guess: this hack is done by a Dutchman. You couldn’t be more right.

At the heart of [Jelle]’s setup is a Raspberry Pi 4 in a watertight enclosure. The tiny powerhouse runs off energy generated by a Forumslader V3, a clever AC-to-DC converter optimized for bike dynamos. The Pi gets internet access via [Jelle]’s phone hotspot, but hosting a site over cellular networks isn’t as simple as it sounds. With no static IP available, [Jelle] routes web traffic through a VPS using an SSH tunnel. This crafty solution—expanded upon by Jeff Geerling—ensures seamless access to the site, even overcoming IPv6 quirks.

The system’s efficiency and modularity exemplify maker spirit: harnessing everyday tools to achieve the extraordinary. For more details, including a parts list and schematics, check out [Jelle]’s Hackaday.io project page.

An ESP Makes A Bicycle Odometer

If you’d like to measure the speed of your cycling then it’s easy enough to buy a cycle computer, but as [Clovis Fritzen] has done it’s also an option to build one. The result of his work is a smart PCB on which the speed is indicated with a row of LEDs.

The sensor is a straightforward affair, a reed switch with a magnet on a wheel, which is sensed by an ESP8266. The six LEDs are charlieplexeed over three lines. To keep the supply voltage correct for the ESP from the uncertain state of a lithium battery, a small buck-boost module is used. Sadly the code doesn’t seem to make the speed available via the wireless part of the processor, but we’re guessing that a bit of extra software work could fix that.

The result when put in a box on the handlebars, is a smart but simple instrument that would aid any bike. It’s by no means the first one we’ve brought you and we doubt it will be the last.

A Bicycle Trailer Fit For Heavy Haulage

One of the problems of being a cyclist is that a bicycle just isn’t designed to carry much more than a human. You can get panniers and hang shopping bags from the handlebars, but sooner or later there’s a load which just doesn’t fit. At that point there’s only one way forward that involves staying on two wheels: find a bike trailer. If you fancy building one yourself, then there’s La Charette (French language, Google Translate link), an open-source three-wheeler design from France.

Construction is a sturdy welded box section tube spaceframe, with the single wheel at the front providing steering, and a towing bar attached to the seat post of the bicycle. Along with the impressive load capacity comes the problem of towing it, and for the cyclist with less-than-superhuman strength there’s the option of an electrically-driven front wheel. Stopping the whole thing is an essential feature with loads this size, and to that end there’s an inertial braking system operated by the force on the towing bar.

All in all it appears to be a useful trailer, albeit on the large side for storage when not being used. It’s certainly one of the larger bike trailers we’ve seen, though not perhaps the most stylish.

Thanks [Jeff] for the tip!

A bike computer sits on a wooden background. The back of the bike computer has a 3D printed attachment with two white translucent zip ties running through the back.

Repairing A Bike GPS With 3D Printing

We love hacks that keep gadgets out of the trash heap, and [Brieuc du Maugouër] has us covered with this 3D printable replacement mount he designed for his bike GPS.

One of the most frustrating ways a gadget can fail is when a small, but critical part of the device fails. [du Maugouër] combined a 3D printed back and four M2x6mm screws to make a robust new mount to replace the broken OEM mount on his handlebar-mounted GPS. Slots for zip tie mounting are included in case the replacement mount breaks before yet another replacement can be printed. Apparently [du Maugouër] agrees with Chief O’Brien that “in a crunch, I wouldn’t like to be caught without a second backup.” [Youtube]

It’s exciting that we’re finally in a time when 3D printed replacement parts are living up to their potential. This would be a lot easier if more manufacturers posted 3D printed design files instead of getting them pulled from 3D file platforms, but makers will find a way regardless of OEM approval.

We’ve covered a lot of bike hacks over the years including DIY Bike Computers and GPS Trackers. Do you have a project that keeps something from becoming trash or might save the world another way? There’s still time to enter the Save the World Wildcard round of the Hackaday Prize (closes October 16th).

An OpenBikeSensor

OpenBikeSensor Measures Close Calls

Cycling is fun, healthy, and good for the environment. But unfortunately it’s not always the safest of activities, as inconsiderate drivers can be a significant hazard to cyclists. Several countries, including Germany, France, and Belgium have introduced legislation mandating a minimum passing distance of at least 1.5 meters between cars and bikes. Enforcing such a rule is tricky however, and without accurate data on average passing distances it’s hard to know how many drivers are following it.

Enter OpenBikeSensor, an open-source hardware and community science project designed to gather exactly this information. Currently in its prototype phase, it aims to make a simple bike-mounted sensor that measures the lateral distance to any passing vehicles. The resulting data is collected online to generate maps highlighting danger zones, which can ultimately be used by city planners to improve cycling infrastructure.

The hardware is based around a set of ultrasonic sensors that measure the lateral distance to any large object. A GPS module keeps track of the bike’s location, while an ESP32 reads out the data and stores it onto an SD card. The user interface consists of a handlebar-mounted display that shows the system’s status. There’s also a button that the user needs to press any time they are passed by a vehicle: this will trigger a measurement and log the location. Once back home, the user can connect the OpenBikeSensor to their WiFi network and download their trip data.

The initial results look promising, and any project that gets people cycling and tinkering with electronics at the same time is worth looking into. It’s not the first time we’ve seen bike-mounted sensors either: people have designed their own sensors to measure air pollution in South America, or simply their own bike’s speed or tire pressure. Continue reading “OpenBikeSensor Measures Close Calls”

Exercise Bike Hacked As Input For Xbox 360

If you like playing Grand Theft Auto, you’re pretty familiar with squeezing the triggers for accelerating and braking while driving around. [David Programa] decided this was too easy, and instead developed a system to allow him to pedal his way around the virtual world.

The device relies on a flywheel-based exercise bike, with six magnets placed on the flywheel that triggers a reed switch six times per rotation. The extra magnets give the system better resolution at slow speeds. A Hall Effect sensor would be a more reliable way to build this to survive in the long term, but the reed switch does work. It’s paired with a debounce circuit to keep the output clean. A Raspberry Pi is pressed into service, running a Python program to read a GPIO pin activated by the reed switch, counting pulses to determine the speed of pedalling.

The trigger control used in the Xbox 360 controller is a potentiometer that creates varying voltages depending on its position, allowing it to act as an analog accelerator input. 0 volts corresponds to no input, while the trigger reads 3.3 volts when fully depressed. The Raspberry Pi emulates this with its PWM output, paired with a low-pass filter to create the relevant voltage to inject into the trigger input on a generic Xbox 360 controller.

While it’s a lot less practical than simply using a regular controller, the pedal controls do allow you to get a great workout while playing Grand Theft Auto. Some of the more intense chase missions should be a great way to get your heart rate up, and that’s got to be a good thing.

Ironically, though, the system only works for cars and motorbikes in game. The bicycles in Grand Theft Auto are controlled by mashing the A button instead. Alternatively, you might consider a similar system for playing Mario Kart on the Nintendo Switch. Video after the break.

Continue reading “Exercise Bike Hacked As Input For Xbox 360”

Cycling Cadence Display With ESP32

Terry Pratchett once said “Wisdom comes from experience. Experience is often a result of lack of wisdom.” This is as true with technical skills as it is with the rest of life, and you won’t truly understand a specific topic unless you’ve struggled with it a bit. [publidave] wanted a simple wireless display for a bluetooth cycling cadence sensor, and soon found himself deep down the rabbit hole of Micropython and Bluetooth Low Energy on the ESP32.

[publidave] had converted his bicycle for indoor training during lockdown and winter, and realized he can’t use the guided training app and view his cadence simultaneously, so he needed a dedicated cadence display. Since [publidave] was comfortable with Python, he decided to give Micropython on the ESP32 ago. Bluetooth Low Energy can be rather confusing if you haven’t implemented it before, especially if good examples are hard to come by. In short, the ESP32 needs to find the sensor, connect to it, select the right service, and listen for the notifications containing the data. The data is then converted to RPM and displayed on a small OLED display. [publidave] does an excellent job of describing what exactly he did, highlighting the problems he encountered, and how he solved them.

In the end, he had a functional display, a good idea of what he would do differently next time, and a lot of additional knowledge and understanding. In our book that’s a successful project.

Since so much of the health related devices work with Bluetooth Low Energy, it could be handy to know the technology and how to interface with it. It would allow you to do things like unbrick a $2000 exercise bike,