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.
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
Key Specifications:
- 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)
Alternate viewing angle:
Click through for a close-up.
Downloads & Resources:
QTI Line Sensor rev 1.0 (.pdf)
Sensor Objects for Propeller Programmers