Today’s examples are all about reading values from the input pins.
The simplest is, of course, the digital button, which is binary (on/off). To get an accurate reading we use a
Digital Button with Pulldown Resistor
The more interesting sensors and readings tend to be more than on/off. This is also where the Arduino can stand apart from some of its rivals that do not have as many (or any) analog inputs.
Analog readings are a number between 0 and 1023 (1024 values total), so quite fine readings can be taken. We can demonstrate this using a Potentiometer (Pot).