Btw, which is better, especially in performance in Line Follower application, QTR-RC or QTR-A?

In QTR-RC explanation, I see “Parallel reading of multiple sensors is possible with most microcontrollers”. How to do that? Because after charging the capacitor of each sensor, we have to wait it for discharging.

Thanks in advance.

–chris tj

With the QTR-RC, the idea is that you charge the capacitors on all of the sensors simultaneously, then measure the time required for each one to discharge. The discharge takes up to about 1-2 ms, so you can read 8 or more sensors 500-1000 times per second.

The QTR-A would be good for someone doing analog circuitry, or for someone who doesn’t want to write a complicated function to drive the sensor. Powerful controllers with multiple ADCs could also use it effectively. But for most applications, I’d recommend the QTR-RC.