Accelerometer-controlled LED Bike Helmet

If you cycle for fun, exercise, commuting, or compulsion, it's important to be well-lit and visible at night. Keeping the helmet lit is a good option because it gives your head extra protection. This helmet, the next in our Lumenhattio project series, has accelerometer-controlled turn signals--just tilt your head right when you're turning right on your bike, and tilt your head left when turning left.

Please note: some of the pictures in this how-to aren't of the best quality. Get in touch with us if you need a clearer picture for any of the steps!

Step 1 Ingredients

For the Helmet/Hat:

• a 2-ft square piece of 1/2" thick sponge neoprene, sponge vinyl, or sponge foam
• non-adhesive grip shelf liner
• bike helmet
• dressmaker's pins
• 1/4" elastic braid
• a few thick hair nets (optional)
• metallic contact paper (optional)
• thread and sewing needle (optional)

For the Circuit:

• Voltage Regulator (see notes in Step 3) with snap battery connector
• Two AA batteries
• One 2x AA battery holder with "snaps"
• Arduino microcontroller with USB connector/cable (A Lilypad is used in this example)
• ADXL3xx accelerometer (again, a Lilypad version is used in this example)
• Six white 10mm LEDs for front lights
• Six red 10mm LEDs for back lights
• Twelve yellow and/or blue LEDs for right and left turn signals
• One Max7221 driver chip. You can order samples of this chip from the Maxim site.
• One 24-pin chip holder (for the Max chip)
• One 8-pin mini-DIN Serial cable, about 2 feet long
• One 4-wire phone cable, about 2 feet long
• Electrical wire
• Breadboard
• One 30 kOhm resistor (or resistors to add to 30 kOhm)
• One 10 microF and one 100 nanoF capacitor
• About 50 jumper cables
• About 30 Alligator clip cables
• 5 small prototyping boards. I used 4 square boards for the LEDS and 1 circular board for the Max chip.

Helpful tools:

• Wire stripper/cutter
• Scissors
• Soldering iron and Solder
• Needlenose pliers
• Cutting tweezers
• Hot glue gun and glue sticks

Spare parts:

• accelerometer
• Max7221 chips (I blew a couple chips and ended up using 3 total)
• 9V battery (This was what actually blew the chips, I guess my voltage regulator is not the best)

Comments

[plmqaz1243]

Yeah, but does the helmet actually work as a helmet?

Or...
Will it blend?

[hossweightlifter]

Just a little bit hard

[LoliPlop]

Super nice!

[tinker234]

wow be cool to modfiy for my projects

[sadobor]

couldnt you just use a tilt sensor?