I’m currently working on a project that involves line following using the QTR-8RC sensor with an Arduino Mega 2560.
What I’m curious is how can I tell the robot to stop if the sensors read a solid black line so that I can tell the robot to perform an operation?
I moved your thread to the Sensors category of our forum since it seemed more appropriate.
You can find details for a couple ways to read the sensors under the “Reading the Sensors” heading of the QTRSensors Methods & Usage Notes found in the Arduino Library for the Pololu QTR Reflectance Sensors documentation.
Essentially, you can look at the readings from each sensor and compare them to some threshold to try to determine if they are seeing black or white. For example, if you want to check to see if they are all over a black surface, you can compare each sensor reading to a threshold and use the logical AND
&& operator. This is how the maze solving example for our 3pi Robot works to find the end of the maze, so you might find the code in that example helpful as a reference.