Color sensor help please

Help & Support Robot Parts
1

Hey guys,

Im working on creating a “line follower robot” that has 3 possible paths (red / blue / green tape) that all intersect at a shared start point. I am trying to find a light sensor that will be able to detect the correct color and follow the right path.

From what I understand, the way the sensors work is that light is bounced off a surface (the tape) and read back via a photoresistor. From there depending on the intensity you can tell the color. Am i correct in that understanding?

I have been looking at these two sensors

robotshop.com/pololu-qtr-infrared-sensor-array-1.html

robotshop.com/parallax-infrared-line-follower-kit-2.html

I was on another internet “shop” asking about a sensor they had, that said the sensor “Can Detect color difference” after inquiring with a representative from their website they said it can only detect black and white.

robokitsworld.com/index.php?main_page=product_info&cPath=11&products_id=43

Can anyone suggest a color sensor for me? or point me in the right direction thank you

2

The line following sensors that you chose can only detect the reflectivity of IR light. In practice this means they can only detect the difference between black and white.

A colour sensor, would shine white light onto an object and then measure (using photodiodes mostly) how much light is there for each of the primary colours red, green, and blue. From those components you can then determine what colour was sensed.

In your case, it seems you will need at least three colours sensors (in order to know if you are centered on the colour line, or too far right or left).

Perhaps these sensors could be of use: RB-Plx-200 or RB-Dfr-153