Dave from Plastibots had some fun with the brake lights of his Nissan Juke. He added some red LED lighting strips to the car and made a custom circuit to drive them. He is getting power from the parking lights and taking in a signal from the brake lights. When only the parking lights are on the lighting strip is PWM controlled to a level of 75%, when the brake is applied the lights are turned on with full power. The control is done in a smooth fashion. I like this since lots of vehicle lighting these days turns on and off very sharply since most of the lighting is LED. I miss the days of incandescent bulbs which had an inherent brightening and dimming delay.
“I wanted to also monitor and react to braking to enhance the effect. I decided to go with an ATTiny85 using the Arduino core. It only needed 1 input from the 12V brake power and 1 PWM output to control a MOSFET which in turn powered the LED light strip @ 12V. I built one controller per tail light.”
