Arduino Workshop 3rd session In this session, you will find - What are the PWM pins and how it works? - What is the serial monitor? - What are the sensors? - Start building a home automation system. - Start using some sensors (LDR for light intensity - LM35 for temperature - PIR for personal infrared) on the home automation system.

1. Astrobot
SESSION 3

4. Breadboard

5. Jumpers

6. Polarity

7. Linear Resistors

8. Arduino board

9. Arduino
Software

10. Here you can define :
-global variables.
-your needed libraries.
-any functions you may need.
Here you can make initialization for :
-pins (type of it I/O ).
-libraries.
Execution of some orders once only .
Put your code here

11. Some Arduino’s functions
pinMode(pinNum, INPUT/OUTPUT)
digitalRead(pinNum)
digitalWrite(pinNum, HIGH/LOW)
analogRead(pinNum)
analogWrite(pinNum, value)
delay(time in milliseconds)

12. Analog Signals

13. Using digital pins to get Analog Signal

15. Pulse Width Modulation (PWM)
• PWM pins (~) in Arduino Uno  3, 5, 6, 9, 10 & 11.
• Used to get analog signal from Arduino.
• We use analogWrite(value)
• 0  255

18. Duty Cycle
• 𝐷 =
𝑂𝑛 𝑡𝑖𝑚𝑒
𝑇𝑜𝑡𝑎𝑙 𝑡𝑖𝑚𝑒
.
• 𝑇𝑜𝑡𝑎𝑙 𝑡𝑖𝑚𝑒 = On time + Off time.
• 𝑁𝑒𝑤 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 = 𝐷 ∗ 𝑉𝑜𝑙𝑡𝑎𝑔𝑒 (𝑖𝑒. 3.3, 5)
To reduce the intensity of led to 50% 5 * 50% = 2.5,
So we need 2.5 V
0 VOLT 5 VOLT
0 255

19. map function
• Used to change from range to another easily.
• 𝑚𝑎𝑝 𝑣𝑎𝑙𝑢𝑒, 𝑓𝑟𝑜𝑚𝐿𝑜𝑤, 𝑓𝑟𝑜𝑚𝐻𝑖𝑔ℎ, 𝑡𝑜𝐿𝑜𝑤, 𝑡𝑜𝐻𝑖𝑔ℎ
• Example :-
• map(150, 0, 255, 0, 5) returns 2.9411…

20. Serial
Monitor

23. LDR Sensor

25. The Sensor Type

27. Code

30. LM35 Temperature
Sensor

34. Code

35. PIR Sensor

36. How it can Work?

37. PIR Sensor component

38. Connection with Arduino
board