This project was developed as part of the University of Pittsburgh's Swanson School of Engineering course ENGR1716 The Art of Making: An Introduction to Hands On System Design and Engineering.

The Firefly Pack.mov

See Our Wearables Technology in Action!

See Firefly Pack in use, the visible and hidden components, circuits and more!

What Does it Do?

When turned on, bikers can use Firefly Pack to signal to drivers that they are on the road in front of them. When a stretch sensor is pulled, the light on the corresponding side flashes a different color to alert drivers that the biker is turning.

Who Does it Help?

Firefly Pack helps both bikers and drivers. Bikers can bike at night more safely by being made more visible to drivers. Firefly Pack additionally helps drivers be aware of the presence of a nighttime biker and which way the biker may be turning

Why is it Useful?

Firefly Pack allows for bikers to be visible at night to drivers behind them. Additionally, drivers can see when a biker is turning at night. These features make nighttime biking safe for both bikers and drivers.

How it Works

The Firefly Pack is created with two duplicate circuits (one for each side). One circuit is shown to the left. In this setup, the Adafruit Flora board sends power through a 10 kilo-ohm resistor via the 3.3V pin connected to the battery pack. On the other side of the resistor, one wire connects to the stretch sensor, and the other connect back to the Flora board. This is to allow an analog input from the stretch sensor (the users pull) to travel back to the Flora board. The other end of the stretch sensor is connected to one of the GND (ground) pins to complete the left hand circuit.

To the right of the Flora board, the NeoPixel Jewel is turned on and off with a slide switch, powered by the VBATT pin connected to the battery pack. The NeoPixel Jewels serve as the backpack's turn signals. The Jewel receives input from Pin 6, which is the output signal delivered from the stretch sensor to Pin 10. This causes the Jewel to change colors when the stretch sensor is pulled by the user. A status LED is between the Flora board and the Jewel to let the biker know the system has been powered on successfully. Finally, the Jewel is connected to the Flora board's other GND pin to complete the circuit.