Picture of LilyPad Arduino Blinking Bike Safety Patch
I made this embroidered patch in a different instructable, but here I'll show you how to add flashing LEDs to your backpack for fun and safety. I used a LilyPad Arduino with a rechargeable lithium-polymer battery for flatness and re-usability. The LEDs blink in a marquee pattern, two at a time, in patriotic red, white and blue, in fitting with this year's "Re-Make America" Maker Faire theme. Check out this project on Make: Projects and the video from CRAFT.

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Step 1: Materials and Tools

Picture of Materials and Tools
Materials and Tools:
-needlenose pliers
-sewing needle
-LilyPad Arduino with programmer and USB cable - Maker Shed

-LiPower board - Sparkfun
-lithium-polymer battery (and charger) - Sparkfun
-LilyPad AAA battery holder (comes with the Maker Shed kit linked above)

-conductive thread - Lame Lifesaver
-conductive velcro - Less EMF
-sticky-back velcro (I got mine at Michael's)
-bag or backpack
-fabric patch to mount circuit
-small scrap of fabric for switch
-source code and schematic

Coil the leads of each LED: make the longer lead (positive) into a square spiral, and the shorter lead (negative) into a round spiral.

Step 2: Sew the LED grounds

Picture of Sew the LED grounds
Check out the schematic. Using your conductive thread, sew a line around the perimeter of the patch, stopping to sew the round leads of each LED into the line. Leave a space on one edge for the conductive velcro (don't sew the velcro yet).

Step 3: Sew the power supply and LilyPad

Picture of Sew the power supply and LilyPad
Cut one side of the conductive velcro in half, and sew the bottom half over the edge of the patch where you left that space earlier. Sew it down and sew a line over to the + on the LiPower unit (you can also use the LilyPad AAA battery board). The picture shows it sewn to ground, but don't pay attention to that! =]

Sew the other conductive velcro tab down next to (but not touching) the previously-sewn tab. Stitch a line to the + on the LilyPad Arduino. I reinforced these two power leads a few times to reduce the resistance of this switchable area.

Stitch the ground of the power supply to the line of grounds around the edge. Same goes for the LilyPad Arduino. Look at that schematic for help placing the traces.
ingamarie4 years ago
Awesome, that was a fun project. I ended up using the 'Simple' Lilypad and only 8 lights, lining the back to protect the electronics, and making it snap on instead. Thanks so much!
hadimatin4 years ago
You are great. Excellent.
Watch your patch animation while listening to Franz Ferdinand's Take me out. After the Ritardando at about 1:00 the LEDs sinc up. The same two blink on the quarter note and then it moves on counterclockwise.

BTW this instructable inspired me to make this...
mbainrot5 years ago
Very nice Instructable :)
rolandblais5 years ago
Based on your cool tutorial, I cobbled together a marquee with my Duemilanove. Thanks for the inspiration!
bekathwia (author)  rolandblais5 years ago
looks great! I also <3 animated gifs. =]
miked1235 years ago
Loved this instructable, especially the video. Hope you start making a lot more. (oh and awesome music at the end of the video)
biphenyl5 years ago
This is so cool! (and a fantastic animated gif, haha) The velcro was a great idea for removing at the airport or on a rainy day!
whopoder5 years ago
Very COOL!
randofo5 years ago
Where is the rap music?