
SENSORS, ADCS AND ACTUATORS 131
Commonly used light sensors are LDRs and photo junction devices.
Sharp (the Company) has developed a good set of proximity and range sensors.
Optical encoders are xed to the wheels of moving vehicles to measure velocity.
Humidity sensors are used in homes, factories and automobiles.
A to D converters have data and control interfaces
The data interface of ADCs may be parallel or serial.
Displays are a necessity in many embedded systems.
LEDs may be used singly or as seven segment ones.
Seven segment LEDs may operate in the static or dynamic modes.
OLEDs are a new kind of display devices