Distance Measurement Sensor
GP2Y0A21YK is General Purpose Type Distance Measuring Sensors from Sharp. (see the product page). Sharp Infrared (IR) radiation Distance Measuring Sensor use Infrared signal to measure object distance from 10 to 80 cm with analog output.
Features
Less influence on the color of reflective objects, reflectivity
Line-up of distance output/distance judgement type
Distance output type (analog voltage) : [...]