Parallax USA QTI Proximity Sensor

The QTI Sensor is an infrared emitter/receiver that is able to differentiate between a dark surface) with low IR reflectivity) and a light surface (with high IR reflectivity). These little sensors can be very handy for line following, maze navigation, or sensing the outer rim of a SumoBot ring. Wiring options allow it to be used digitally for fast black/white line following, or as an analog sensor to detect different shades of gray. A daylight filter is built into the sensor.

What does QTI stand for?

• Q = Charge
• T = Transfer
• I = Infrared

When your microcontroller measures the time it takes for the QTI's capacitor to decay, it's measuring a rate of charge transfer through an infrared phototransistor. This rate indicates how much infrared is reflecting off a nearby surface.

Key Features:

• Capable of analog or digital outputs
• No-contact surface sensing
• Unfocused for sensing diffused surfaces
• Daylight filter on sensor
• Easy to interface with any Parallax microcontroller
• Power requirements: 5 VDC
• Communication: Analog output of capacitor decay time depending on level of infrared reflectivity
• Dimensions: 1.25 x 0.37 in (31.7 x 9.4 mm)
• Operating temp range: -40 to +185 °F (-40 to +85 °C)