I really like the space theme on the backpack – it works great with the LEDs! Via Andre5000 on Instructables
Modify your own backpack in this tutorial and give it an extraterrestrial look with smart LEDs! Use it as a bike safety gadget or just to show your love for space and your favorite constellation! The Orion constellation is one of my favorites. I’m using an Arduino Lilypad (Simple Board version) which has five PWM (pulse-with modulation) pins. These digital PWM pins can add a nice glimmer effect to the LEDs, so they look like real stars! Because the Lilypad supports up to 5 PWM pins (Adafruits Gemma V2 supports only 2 PWM pins), I recreated Orion’s head (3 pins), a part of the belt (1 pin) and the right feet (1 pin). I later noticed that it kinda looks more like a mirrored Libra, which is cool though. Here is good constellation map, take a look! Which constellation will you choose for your backpack modification? So for this project you will need five white LEDs. Furthermore you need a photoresistor, a 10KΩ resistor, a small lipo battery and a lipo charger as well (you can use at least 3 AA or AAA batteries alternatively). The photoresistor controls the intensity of the light, depending on the brightness of the sorrounding. If it’s getting dark the lights are more dimmed. In the sunlight the lights are brighter to be discernible (reversable in the code, so that you can save energy in bright sunlight). Besides the photoresistor produces a cool shining effect of the LEDs, like real stars! If you prefer, you can use ultra bright LEDs (by Adafruit for example) to make your backpack more noticeable especially in bright light. To power the Lilypad I’m using a lipo battery pack with 3.7V and 400mAh. When activated, the backpack lasts about 8 hours (which is pretty good in my opinion). To upload the code to the Lilypad, you need an FTDI module/adapter and wires.
Every Wednesday is Wearable Wednesday here at Adafruit! We’re bringing you the blinkiest, most fashionable, innovative, and useful wearables from around the web and in our own original projects featuring our wearable Arduino-compatible platform, FLORA. Be sure to post up your wearables projects in the forums or send us a link and you might be featured here on Wearable Wednesday!
Source: Adafruit – Wearables