how to build a sensor/receiver that revives green and red light?

hi guys
i hope you can help me out. i am competing in a roborace (www.roborace.co.za)
we need a sensor that picks up a green light so that the car can start moving forward,
then we also need a sensor that picks up red light in order to stop the car.

i know you can use a normal LED and connect it the wrong why around apparently  it can pick up the same  color as what the LED is emitting
example: Green Led will pick up green light.

can someone please help me out

Kind regards

lemonie3 years ago
Put a filter* over your sensor. Green filter - green light.


*thin, coloured plastic.
marcelalfa (author) 3 years ago
thanks ill try figuring it out. thanks for the info
caitlinsdad3 years ago
You can try this http://laser.physics.sunysb.edu/~tanya/report2/ You probably then need a microcontroller such as an arduino to take the sensor reading and control the appropriate movement of the motors.Good luck.