Mindstorms Sensor

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How could i use lejos for legos mindstorms to use a colorlight sensor to follow a straight black line?

Hi Josh,

[01] I couldn’t find technical information about your color sensor (a link to a datasheet would be helpful), so I will assume that it works on the same principles as most of the hobby color sensors.

[02] Typically, robots that are designed to follow black line use two (2) optical sensors fixed some distance apart. Each sensor’s output is proportional to the amount of light which is reflected from under the sensor; line reflects less than the floor. When the robot is on the line, the sensors are located somewhat symmetrically on either side of the line, and their outputs are the same (or close). When the robot drifts off the line slightly, one sensor sees more line that other, the difference between their outputs increases, and the robot can take corrective action (e.g. turn to get back on the line).

[03] The method described in [02] typically uses IR LED(s) and photodiodes or prototransistors. But it could be done with two (2) color sensor as well.

[04] You could use a single color sensor, if you can modify the design of your line, and have blue and red lines running next to each other. When the robot deviates from the line, the color sensor would see increase in either red or blue.

Hope it helps!

- Nick