QTR-3RC Reflectance Sensor Array - Digital

QTR-3RC Reflectance Sensor Array - Digital info

QTR-3RC 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 three 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. This measurement approach has several advantages, especially when multiple units are used:

• No analog-to-digital converter (ADC) is required
• Improved sensitivity over voltage-divider analog output
• Parallel reading of multiple sensors is possible with most microcontrollers

The LED current-limiting resistors are set to deliver approximately 17 mA to the LEDs when VCC is 5 V, making the total board consumption just over 50 mA.

QTR-3RC Reflectance Sensor Array - Digital  - General Specifications

• Line sensor
• General purpose proximity or reflectance sensor
• 3 IR emitter and receiver pairs
• No ADC required
• Improved sensitivity
• Parallel sensor readings possible
• Maximum 9.5mm sensing range

QTR-3RC Reflectance Sensor Array - Digital  - Technical Specifications

• Dimensions: 32mm x 8mm x 3mm (without header pins installed)
• Operating voltage: 5.0 V
• Supply current: 50 mA
• Output format: 3 digital I/O-compatible signals that can be read as a timed high pulse
• Optimal sensing distance: 3 mm
• Maximum recommended sensing distance: 6 mm
• Weight without header pins: 0.6 g

Videos

Documents

QTR-3RC reflectance sensor array schematic diagram 

Datasheet for the Sharp GP2S60 compact reflective photointerrupter 

Pololu QTR Reflectance Sensor Application Note: https://www.pololu.com/docs/0J13

Pololu AVR C/C++ Library User’s Guide: https://www.pololu.com/docs/0J20

Arduino Library for the Pololu QTR Reflectance Sensors: https://www.pololu.com/docs/0J19

Pololu AVR Library Command Reference: https://www.pololu.com/docs/0J18

References

Pololu Web Site: https://www.pololu.com/product/2457