
SENSORS, ADCS AND ACTUATORS 87
3.1 | Sensors
Remember the block diagram (Figure 1.2) that we started with. Any embedded system
needs sensors—depending on the application, it may be just one sensor or as in most
cases, many sensors. A sensor converts a physical quantity into a corresponding voltage.
Take an application like a home security system—there should be sensors for sensing
temperature, light, motion, humidity, etc. e data obtained from these sensors decide
the course of action for the actuators of the system. In this section, we take a quick look
at some of the commonly used sensors.
3.1.1 | Temperature Sensors
3.1.1.1 | Thermistor