Analog Input
Analog input refers to measurement of a voltage from an external source such as a sensor or a potentiometer. In this context, “analog” refers to a signal that is varying continuously, in contrast to a digital signal that only takes on two discrete levels.
An example of an analog signal is a sensor measuring the temperature in a room. The sensor reading could be any value within a range of temperatures.
An example of a digital signal is a lightbulb controlled by a simple on/off switch: the light is either on or it is off. Replacing the on/off switch with a dimmer switch would convert the digital on/off state of the light to an analog range of brightness between off (dark) and fully on.
The analog input capability of an Arduino enables the Arduino to measure voltages that represent (or are caused by) some external stimulus. Therefore, analog input is an important way to make an Arduino board to responsive to its environment.
Applications
- Sensor readings
- Potentiometers for user input