Analog and Digital Signals Binary Code 7 th

Analog and Digital Signals Binary Code 7 th Grade Science

DO NOW MONDAY • Write down what you think binary code is or what you think this term means.

Learning Targets Today’s PLAN Today’s DO • We will view Power. Point slides to help us differentiate between analog and digital signals. • We will practice decoding binary code messages and make our own binary code messages.

To differentiate between digitized analog signals. . Types of Signals Analog Signals: • Continuous • Never-ending range of values • More exact, but more difficult to work with Digital Signals • Discrete • Only 2 values (0 and 1 – binary code) • Not as exact, but easier to work with Example: • A digital thermostat in a room displays a temperature of 72. An analog thermometer measures the room temperature at 72. 482. • The analog value is continuous and more accurate, but the digital value is more than adequate for the application and significantly easier to process electronically.

To explain how binary code is used to communicate by making sound or text on screens. Examples of Analog Signals: • Sine waves and square waves are two common examples of analog signals. • Digital signals can be square waves too but this square wave is not digital because it goes into the negative range (below the x-axis) 0 volts Sine Wave Square Wave (not digital) Random-Periodic

Examples of Analog Signals: • Digital signal are commonly referred to as square waves or clock signals. • Their minimum value must be 0 volts (OFF=0), and their maximum value must be 5 volts (ON=1). • They can be periodic (repeating) or non-periodic. 5 volts------ 0 volts------

Electronics: How do they work? ON OR OFF

Computer and Circuits • Are always in one of two states: – On – Off • This is encoded by the Binary System. • The Binary System tells computers ad circuits which wires need to be on and which need to be off.

The Binary System • Also called the Base-2 System because it has 2 numbers. • The number system computers use at the most basic level. • Uses only TWO numbers – 0 – 1

How does it compare to our number system? • Our number system: the decimal system • Is a Base-10 system because it uses 10 numbers – 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 • Base-2 System: Binary System • Uses only 2 numbers – 0, 1 – O = Off and 1= On

The Binary System • All circuits are either switched ON (1) of OFF (0). • All data is stored as combinations of 0 and 1 (called binary numbers) – 01 – 101 – 001 – 1110 – And so on…. .

How does it work? • Since it is a Base-2 system, all places in the binary number represent a number multiplied by 2. • We will keep it simple and use up to 5 digit binary numbers. • This means that we will use binary numbers that have 5 digits (0’s or 1’s) or less.

Example • All blanks will contain either a 0 or 1 (binary number). • Each blank represents a value. This value is determined by multiplying the previous number by 2 (since it is a Base-2 system). • Always start with a 1, numbering from the RIGHT SIDE of the blanks _____ _____ 16 8 4 2 (8 x 2) (4 x 2) (2 x 2) (1 x 2) 1

Example • If the blank has a 0 in it, you do not add the number. (That circuit is off and so is not counted. ) • If the blank has a 1 in it, then that numebr is added. (That circuit is on and the is counted. ) __1_ __0__ __1__ 16 8 4 2 1 (on) (off) (on) 16 +2 +1 = 19

Example • Then use a chart that tells what number represents each letter of the alphabet to determine what letter of the alphabet that binary number represents. a b c d e f g h i j 1 2 3 4 5 6 7 8 9 10 k l m n o p q r s t 11 12 13 14 15 16 17 18 19 20 u v w x y z 21 22 23 24 25 26 19 = s So 10011 represents the letter “s” in binary code

Now Let’s Try Another • What letter does this binary number represent? 1 0 1 16 8 4 2 1 16+ 4 +2 +1 = 23 = w (Remember to add only the numbers that are ON - have a 1 in the blank)

What letters are represented by the following binary codes? 151 2 21 312 0 1 1 1 0 0

Write the following numbers in Binary Code. 15 21 12

Write the following letters in Binary Code. 15 J O 21 12 Y

Are you now able to…. I still feel unsure. I need some more help to understand. I feel ok. I need to do some more work to check my understanding. I am happy and feel I understand can explain the main points.