Introduction to the keypad interface - Arduino Tutorial

- [Narrator] A keypad is a common hardware interface so let's see how we can set up one with our Arduino board. The keypad type we're using is four by three which means four rows and three columns. Each point is a pushbutton arranged this way. Each pushbutton is an active low type. This is the arrangement for an active low pushbutton. We have a voltage source, VCC, and a resistor. We call the resistor a pull-up resistor, then a pushbutton connected to ground. And in order to read the value of the active low pushbutton we connect the controller pin between the pull-up resistor and the pushbutton. Active low simply means when the switch or the pushbutton is closed or pressed, it sends a low signal to the microcontroller. So as the name says it, when it's active, it sends a low signal. When the switch is not pressed, it sends a high signal. An active low pushbutton uses a pull-up resistor. It pulls up the value to high when it's…