Dimensions : 2.95″ x 0.5″ x 0.125″ (without header pins installed) Operating voltage : 3.3-5.0 V Supply current : 100 mA Output format : digital I/O compatible

Product Description

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). Each phototransistor uses a capacitor discharge circuit that allows a digital I/O line on a microcontroller to take an analog reading of reflected IR by measuring the discharge time of the capacitor. Shorter capacitor discharge time is an indication of greater reflection.

The outputs are all independent, but the LEDs are arranged in pairs to halve current consumption. The LEDs are controlled by a MOSFET with a gate normally pulled high, allowing the LEDs to be turned off by setting the MOSFET gate to a low voltage. Turning the LEDs off might be advantageous for limiting power consumption when the sensors are not in use or for varying the effective brightness of the LEDs through PWM control.

Specification

General

Material

Aluminium, Plastic

Dimensions

2.95″ x 0.5″ x 0.125″ (without header pins installed)

Operating voltage

3.3-5.0 V

Supply current

100 mA

Output format

digital I/O compatible

Optimal sensing distance

0.125″ (3 mm)

Maximum recommended sensing distance

0.375″ (9.5 mm)

Weight without header pins

0.11 oz (3.09 g)

Dimensions

Length

7.50 cm

Width

1.30 cm

Height

0.20 cm

Other parameters

Weight

5.00 g