Revise: Digital Electronics and Communication System

Every system: input, process, output.

A smoke detector: sensor, comparator, alarm.

Binary place values: 1, 2, 4, 8, 16 (powers of 2).

1011 (binary) = 11 (decimal).

AND: all inputs 1. OR: at least one input 1.

AND with A=1,B=0 gives Y=0.

Transmitter -> channel -> receiver.

A radio station broadcasts through the air to a car radio.

Applies to devices of any internal complexity.

A streetlight: light sensor, control circuit, relay.

Digital signals resist noise far better than analog.

The rightmost bit is always the smallest place value.

Every digital circuit is built from combinations of basic gates.

A seatbelt-AND-brake interlock is exactly an AND gate.

Modulation encodes information onto a carrier wave.

FM resists noise better than AM.