Friday, 14 September 2012

Burningman wireless bike lights

Some good friends of mine wanted some bike lights for Burning man this year, but did not want just bike lights. 

RGB wireless bike light

So I created them wireless bike lights that beep and flash like a car alarm arming/disarming. When in the on mode the head light is on and a string of LED will pulse allowing them to see and be seen.

For the electronics I used one of my Arduino based RFnode as a base but to drive the power hungry LEDs I used a STA301A connected to 3 of the PWM pins of the ATmega168. This allowed me to drive 3 strings of LEDs with PWM support. 

I got a little creative and limited by space and time I mounted the STA301A to the RFnode with some hot glue and mounted surface mount resistors directly to the pins of the IC. Most of the wiring was air wiring as I did not have time to get a customer board fabricated.

For the radio instead of using the nRF24l01+ I found some small key finder fobs that can stay powered from a coin cell battery for months so decided to use them as I could get the power consumption down to less then 1mAh when in sleep mode.   

I was in a bit of a rush to get the units finished before Burningman so I don't have any pictures of the hardware jammed back into the bike light casing and the extra wiring of the LEDs yet. I might add that one they get back.

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