What are analog devices? - Arduino Tutorial

- [Instructor] There are two types of components that we interface with in Ardiuno, digital and analog. Digital devices produce two possible values as their output, either zero or one. We may also refer to these as high or low. An example would be a push button switch- it's either on or off. However, analog sensors can produce a continuous number of possible output values. Some examples of analog components are: light dependent resistors, which can be used as a light sensor, temperature sensors, stepper motors, and joystick controllers. There are many different ways to measure the analog output they produce. Voltage is a common analog output. So when working with analog sensors, we need to know what type of output the sensor produces in order to properly use it in the program. This allows us to control the brightness of an LED, the speed of motor, and so on. Typically, analog sensors output one of these three physical electrical properties: voltage, resistance, or capacitance. An example of an analog sensor that produces voltage is a temperature sensor, such as TMP37 and LM35. When working with sensors that produce voltage, we need to know the voltage range that the sensor outputs, and take into consideration the voltage reference that Arduino is using. An example of this type of sensor is an LDR, or light dependent resistor. An example of a capacitance sensor is a touch sensor. Here's a simple touch sensor that was included in my Ardiuno kit.