About Boolean logic
Boolean logic is understanding the logic with which Boolean expressions are evaluated. The Boolean expressions this course covers are NOT, AND, OR and XOR. Each one has its own logic circuit symbol, truth table, and
Boolean expression symbol. Logic gates are the building blocks of electronic circuits and part of household devices and computer management systems.
Boolean NOT
The Boolean NOT takes just one input and the output is the oposite of the input i.e. If the input is 0 the output is 1 and if the input is 1 then the output is 0.
Boolean OR
The Boolean OR takes two inputs and outputs 1 if either input is 1. Only when neither input is 1 will the output be 0.
Logic circuits
Logic gates can be combined to create more complex cicuits. Logic gates form the basis for many things in Computer Science including having a role in household devices.
Below you can see the logic circuit and truth table for a circuit that models some self opening doors at a shopping center. Input A is the outside sensor to detect movement. Input B is the inside sensor.
Input C is the on/off switch for the doors. if someone approaches either door and the door is switched on the output will be 1 (Door opens).
