Sumo collision detection on white surface with black border

i am a beginner here.
i recently got the zumo robot for arduino uno. the zumoexamples are good enough to learn.
if i want to run the sumo collision detect on white surface area with black border. what are the changes need to be done in the arduino program to get it done successfully.

any help will be appreciated.
thank you. :relaxed:

Dear vamsiB3,

To use a white surface area with a black border you simply have to INVERT THE PHASE of the sensor’s output.

For example, normally in the BORDER DETECT SKETCH you have the expressions:;
 if (lineSensorValues[0] < QTR_THRESHOLD)

For a white surface area you modify:;
 if (lineSensorValues[0] > QTR_THRESHOLD)

This has been tested and works perfectly with QTR_THRESHOLD 700 on my Zumo 32U4 with 100:1 motors.