When riding racing bikes in groups, people follow each other with minimal distance between their wheels to reduce wind resistance. As a result, only the first rider is able to properly see the road, while the view of the following people is blocked and they are unable to see any hazards or the shape of the road. This information is usually handed down from the first to the last biker by hand signals. However, taking one hand off the handlebar at high speeds is dangerous or even not possible when both hands are on the break.
What it does
The Adidas Save Light (SL) Jacket has 3 horizontal LED stripes integrated seamlessly into the back of the jacket. So far, it has two main functionalities:
1) The LEDs will illuminate when the breaks are activated. One stripe is activated if the breaks are slightly pulled. Two stripes when pulled harder and three flashing stripes for a hard stop.
2) The LEDs will swipe in the direction of the turning maneuver to indicate turns when a button on the left or right handlebar is pressed.
How we build it
A hidden inlay has been sewn into the back of the Adidas jacket with pockets to hide the LED stripes. The LED actions are controlled by a GENUINO Board and powered with a portable battery pack. The break intensity is measured with a 3D printed break sensor. Three metal brushes in the sensor detect how strong the break lever is pushed and send this information to the GENUINO Board.
Challenges we ran into and accomplishments that we are proud of
Look and Feel of the jacket: one of our main goals was to make the jacket look nice by hiding the LEDs and other components within the jacket. In our solution, the LEDs are not visible when they are turned off. Measuring break intensity: the challenge of finding a reliable way to measure at least 3 different nuances of break intensity has been solved with a mechatronic, 3D printed solution which works accurate and reliable. Basis for Bluetooth communication established: the jacket is ready to be connected to your smartphone to show e.g. status of LED and remaining charge.
What we learned
1) Connection via Bluetooth between several devices was not as easy as we thought. 2) Simple solutions sometimes work best: break sensor with basic mechatronics outperforms pressure sensor in terms of reliability. 3) Sometimes a new technology opens heaps of possibilities but it is important to focus on a specific use case in order to deliver reliable results.
Establish reliable Bluetooth connection between the bike, the jacket and a smartphone. Enable backlight option for the night: activate some LEDs in the middle of the jacket permanently.