Pololu Reflectance Sensor Array Module QTR-8A

The QTR-8RC reflectance sensor array is intended as a line sensor, but it can be used as a general-purpose proximity or reflectance sensor. The module is a convenient carrier for eight IR emitter and receiver (phototransistor) pairs evenly spaced at intervals of 0.375" (9.525 mm).

To use a sensor, you must first charge the output node by applying a voltage to its OUT pin. You can then read the reflectance by withdrawing the externally supplied voltage and timing how long it takes the output voltage to decay due to the integrated phototransistor. Shorter decay time is an indication of greater reflection.

FEATURES:

1. No analog-to-digital converter (ADC) is required
2. Improved sensitivity over voltage-divider analog output
3. Parallel reading of multiple sensors is possible with most microcontrollers
4. Parallel reading allows optimized use of LED power enable option
5. Operating voltage: 3.3-5.0 V
6. Supply current: 100 mA
7. Output format: 8 digital I/O-compatible signals that can be read as a timed high pulse
8. Optimal sensing distance: 0.125" (3 mm)
9. Maximum recommended sensing distance: 0.375" (9.5 mm)

PACKAGE INCLUDES:

1. 1 X Pololu Reflectance Sensor Array Module QTR-8A