1. Analog and Digital Signals Binary Code 7th Grade Science

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

3. Learning Targets To explain how binary code is used to communicate by making sound or text on screens. To differentiate between digitized and analog signals.. Today’s PLAN Today’s DO We will view PowerPoint slides to help us differentiate between analog and digital signals. We will practice decoding binary code messages and make our own binary code messages.

4. Types of Signals To explain how binary code is used to communicate by making sound or text on screens. To differentiate between digitized and analog 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.

5. Examples of Analog Signals: To differentiate between digitized and analog signals.. To explain how binary code is used to communicate by making sound or text on screens. 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 WaveSquare Wave (not digital) Random-Periodic

6. Examples of Analog Signals: To differentiate between digitized and analog signals.. To explain how binary code is used to communicate by making sound or text on screens. 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------

7. Electronics: How do they work? ON OFF OR

8. 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.

9. 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 –0–0 –1–1

10. 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

11. 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 –1001 –1110 –And so on…..

12. 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.

13. 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 ____ _____ _____ _____ _____ (8 x 2) (4 x 2) (2 x 2) (1 x 2) 124816

14. 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__ __0__ __1__ __1__ 16 8 4 2 1 (on) (off) (off) (on) (on) 16 +2 +1 = 19

15. 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. 19 = s So 10011 represents the letter “s” in binary code abcdefghij 12345678910 klmnopqrst 11121314151617181920 uvwxyz 212223242526

16. Now Let’s Try Another What letter does this binary number represent? 1 0 1 1 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)

17. 15 21 12 123123 0 1 1 1 1 What letters are represented by the following binary codes? 1 0 0 0 1 1 1 1 0 0

18. 15 21 12 Write the following numbers in Binary Code.

19. 15 21 12 Write the following letters in Binary Code. JOYJOY

20. 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 and can explain the main points. To explain how binary code is used to communicate by making sound or text on screens. To differentiate between digitized and analogue signals.