2nd UNIT :

5th. Explain about Python Programming with an example

using ultrasonic sensor or IR sensor.
Solution :
Python is a high-level, interpreted programming language renowned for its readability and
versatility. Its design emphasizes code readability, allowing developers to express concepts in
fewer lines compared to languages like C++ or Java. Python supports multiple programming
paradigms, including procedural, object-oriented, and functional programming, making it
adaptable to various types of projects.
Key Features of Python:
• Interpreted Language: Python executes code line by line, which simplifies debugging
and accelerates development.
• Dynamic Typing: Variable types are determined at runtime, offering flexibility in coding.
• Comprehensive Standard Library: Often referred to as having "batteries included,"
Python's extensive standard library supports tasks ranging from regular expressions to
web development.
• Cross-Platform Compatibility: Python runs on various operating systems, including
Windows, macOS, and Linux, enhancing its portability.
• Community and Ecosystem: A large and active community contributes to a rich
ecosystem of third-party packages and frameworks, extending Python's capabilities in
areas like web development, data analysis, machine learning, and more.

Applications of Python:
• Web Development
• Data Analysis and Scientific Computing
• Machine Learning
• Automation and Scripting
• IoT and Hardware Interfacing

Infrared (IR) Sensor with Python Example

An IR sensor detects objects by emitting infrared light and measuring the reflection. It can be
used for proximity sensing or object detection.
Required Components:
• Raspberry Pi
• IR Sensor Module (e.g., TCRT5000)
• Jumper wires
• Breadboard

import RPi.GPIO as GPIO

import time

# GPIO Mode (BCM)

GPIO.setmode(GPIO.BCM)

# Set GPIO Pins

IR_SENSOR_PIN = 18

# Set GPIO direction (IN)

GPIO.setup(IR_SENSOR_PIN, GPIO.IN)

if __name__ == '__main__':
try:
while True:
if GPIO.input(IR_SENSOR_PIN):
print("Object detected!")
else:
print("No object detected.")
time.sleep(0.5)

# Reset by pressing CTRL + C

except KeyboardInterrupt:
print("IR sensor reading stopped by User")
GPIO.cleanup()

Explanation:
1. GPIO Setup:
• The GPIO pin connected to the IR sensor's output is set as an input.
2. Main Loop:
• The code continuously checks the state of the IR sensor.
• If the sensor's output is high, it indicates that an object is detected.

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 • If the output is low, no object is detected.
• The status is printed to the console every 0.5 seconds.

6th. Describe about features , Pin Functionality of

Raspberry Pi & Node MCU.
Solution :

Raspberry Pi: Features and Pin Functionality

Raspberry Pi is a low-cost, single-board computer designed to encourage programming and
electronic project development. It can be used for a wide range of applications, including IoT,
robotics, home automation, and education.
Features of Raspberry Pi:
1. Processor: Depending on the model, Raspberry Pi uses ARM-based processors. For
example, the Raspberry Pi 4 features a quad-core Cortex-A72 CPU running at 1.5 GHz.
2. Memory (RAM): Available in different configurations, such as 2GB, 4GB, and 8GB
LPDDR4-3200 SDRAM.
3. Storage: No onboard storage; typically uses a microSD card for the operating system and
file storage.
4. Connectivity:
• Ethernet (for network connections).
• Wi-Fi and Bluetooth (Raspberry Pi 3, 4, and later versions).
• Multiple USB ports (USB 2.0, USB 3.0 in Raspberry Pi 4).
• HDMI output for video (dual micro HDMI in Raspberry Pi 4).
5. GPIO Pins: General Purpose Input/Output pins for hardware interfacing (explained
below).
6. Operating System: Runs Linux-based OSes, with Raspberry Pi OS being the most
popular, but can also run Ubuntu, or even Windows IoT Core.
7. Expandable: Supports a variety of accessories like cameras, displays, and sensors for
enhanced projects.
8. Low Power Consumption: Energy-efficient for 24/7 operations in IoT projects.

Pin Functionality of Raspberry Pi (GPIO Pins):

Raspberry Pi has 40 GPIO (General Purpose Input/Output) pins, available in two rows on the
board. These pins can be configured as either input or output, allowing users to control
external components or read data from sensors.
Here’s a breakdown of some key pins:
1. Power Pins:

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 • Pin 2 & 4: 5V power supply.
• Pin 1 & 17: 3.3V power supply.
• Pin 6, 9, 14, 20, 25, 30, 34, 39: Ground pins (GND).
2. Digital GPIO Pins:
• These can be used for digital input (reading buttons, sensors) or output (driving LEDs,
relays).
• Example GPIO pins: 17, 18, 27, 22, etc.
3. Specialized Pins:
• I2C (Inter-Integrated Circuit): Pins 3 (SDA), 5 (SCL).
• SPI (Serial Peripheral Interface): Pins 19 (MOSI), 21 (MISO), 23 (SCLK), 24 (CE0).
• UART (Universal Asynchronous Receiver-Transmitter): Pins 8 (TXD), 10 (RXD).
• PWM (Pulse Width Modulation): Some GPIO pins support PWM for controlling
motors, servos, etc.

NodeMCU: Features and Pin Functionality:

NodeMCU is an open-source IoT platform based on the ESP8266 Wi-Fi module, commonly
used for IoT applications. It features built-in Wi-Fi, making it a go-to choice for projects
requiring wireless connectivity. NodeMCU can be programmed using the Arduino IDE or the
Lua scripting language.
Features of NodeMCU:
1. Microcontroller: Built around the ESP8266 chip, a low-cost Wi-Fi microcontroller with a
32-bit RISC CPU.
2. Wi-Fi Connectivity: Provides 802.11 b/g/n Wi-Fi for IoT applications, enabling easy
integration with cloud services or other network-based applications.
3. Flash Memory: Typically has 4MB of flash memory for code and data storage.
4. GPIO Pins: Several GPIO pins for controlling external components (sensors, relays, etc.).
5. Low Power: Power-efficient design suitable for battery-powered IoT devices.
6. Programming Support: Can be programmed using the Arduino IDE, MicroPython, or
Lua.
7. Small Form Factor: Compact and breadboard-friendly, making it easy to integrate into
electronic circuits.
8. Built-in ADC (Analog to Digital Converter): Single ADC pin for reading analog sensors.
9. Operating Voltage: 3.3V for GPIO operations.
10. USB Interface: Has a micro-USB port for power and programming, enabling easy use.

Pin Functionality of NodeMCU:

NodeMCU has 11 GPIO pins (GPIO0 to GPIO16) that can be used for various purposes like
input, output, PWM, I2C, and UART.

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Here’s a breakdown of the key pins on the NodeMCU:
1. Power Pins:
• Vin: Input voltage (5V via USB).
• 3V3: 3.3V output for sensors.
• GND: Ground.
2. GPIO Pins:
• These pins can be used as digital I/O (input/output) and for specialized functions like
PWM, I2C, and SPI.
• Example: D0 (GPIO16), D1 (GPIO5), D2 (GPIO4), etc.
3. Analog Pin:
• A0: The only analog pin, used to read analog sensors like temperature or light sensors.
It can handle voltage from 0 to 3.3V.
4. Communication Pins:
• I2C:
◦ D1 (GPIO5) as SCL.
◦ D2 (GPIO4) as SDA.
• SPI:
◦ D5 (GPIO14) as SCLK.
◦ D6 (GPIO12) as MISO.
◦ D7 (GPIO13) as MOSI.
◦ D8 (GPIO15) as CS.
• UART:
◦ TX (GPIO1) for transmitting data.
◦ RX (GPIO3) for receiving data.
5. PWM: Pulse Width Modulation can be used on any of the GPIO pins to control things
like motors or LED brightness.

8th. Write a program to interface an ultrasonic sensor

using Raspberry Pi.
Solution:
Ultrasonic Sensor with Python Example
An ultrasonic sensor, such as the HC-SR04, measures distance by emitting ultrasonic waves
and calculating the time it takes for the echo to return after reflecting off an object. This time
delay is used to compute the distance to the object.
Required Components:
• Raspberry Pi

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• HC-SR04 Ultrasonic Sensor
• Jumper wires
• Breadboard
• Resistors (1kΩ and 2kΩ for voltage divider)

import RPi.GPIO as GPIO

import time

GPIO.setmode(GPIO.BCM)

GPIO_TRIGGER = 23
GPIO_ECHO = 24

GPIO.setup(GPIO_TRIGGER, GPIO.OUT)
GPIO.setup(GPIO_ECHO, GPIO.IN)

def distance():

GPIO.output(GPIO_TRIGGER, True)

time.sleep(0.00001)
GPIO.output(GPIO_TRIGGER, False)

while GPIO.input(GPIO_ECHO) == 0:
start_time = time.time()

while GPIO.input(GPIO_ECHO) == 1:
stop_time = time.time()

time_elapsed = stop_time - start_time

distance = (time_elapsed * 34300) / 2

return distance

if __name__ == '__main__':
try:
while True:
dist = distance()

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print(f"Measured Distance = {dist:.1f} cm")
time.sleep(1)

# Reset by pressing CTRL + C

except KeyboardInterrupt:
print("Measurement stopped by User")
GPIO.cleanup()

Explanation:
1. GPIO Setup:
• The GPIO pins are configured using the BCM numbering scheme.
• The TRIG pin is set as an output to send the trigger pulse.
• The ECHO pin is set as an input to receive the echo pulse.
2. Distance Measurement Function:
• A short 10µs pulse is sent from the TRIG pin to initiate the measurement.
• The code waits for the ECHO pin to go high and records the start time.
• It then waits for the ECHO pin to go low and records the stop time.
• The time difference between the start and stop times is used to calculate the distance
based on the speed of sound.
3. Main Loop:
• The distance is measured every second, and the result is printed to the console.
• The loop continues until interrupted by the user.

14th. List the key features of python?

Solution:

Python is a widely-used, high-level programming language known for its simplicity and
versatility.Here are the key features of Python:
1. Simple and Easy to Learn:Python has a clean and readable syntax, which makes it easy
for beginners to learn and write code. The focus on readability reduces the cost of
program maintenance and development time.
2.
3. Interpreted Language:Python is an interpreted language, meaning you don't need to
compile your code before running it. Python code is executed line by line, which makes
debugging easier and allows for interactive testing and rapid prototyping.

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4. Cross-Platform Compatibility:Python is a platform-independent language, meaning
that Python programs can run on different operating systems (Windows, Linux, macOS)
without modification.
5. Dynamic Typing:Python is dynamically typed, meaning you don’t have to declare the
data type of a variable explicitly. The type is determined at runtime, which simplifies
coding.
6. Extensive Standard Library:Python comes with a vast standard library that includes
modules and functions for handling a wide variety of tasks, such as regular expressions,
file I/O, web services, databases, and more. This reduces the need to write code from
scratch for common tasks.
7. Object-Oriented Programming (OOP) Support:Python fully supports object-oriented
programming concepts such as inheritance, polymorphism, and encapsulation, making it
a powerful tool for building large-scale, reusable applications.
8. High-Level Language:Python abstracts away many low-level details such as memory
management and machine architecture, allowing developers to focus more on solving
problems rather than worrying about complex programming details.
9. Interpreted and Interactive:Python supports an interactive mode that allows you to test
and debug snippets of code line by line in the interpreter. This interactive nature makes it
ideal for experimentation and quick testing.
10. Open-Source and Community Support:Python is open-source and free to use, with a
large and active community. This community contributes to a rich ecosystem of third-
party libraries and frameworks, making Python suitable for various use cases like web
development, data science, AI, and more.
11. Multi-Paradigm Language:Python supports multiple programming paradigms,
including procedural, object-oriented, and functional programming. This flexibility allows
developers to choose the paradigm that best suits their project.
12. Embeddable and Extensible:Python can be embedded into applications to provide
scripting capabilities. It also allows the use of libraries and functions from other
languages like C, C++, or Java, making it highly extensible.
13. Automated Memory Management:Python handles memory management
automatically through its built-in garbage collection. Developers don’t need to manually
allocate or free memory, which reduces the risk of memory leaks and errors.
14. Support for Big Data and Analytics:Python is extensively used in data analysis,
machine learning, and scientific computing, thanks to powerful libraries like NumPy,
Pandas, SciPy, TensorFlow, and Scikit-learn.
15. Web Development Frameworks:Python has several robust web frameworks like Django
and Flask that simplify the development of web applications, allowing developers to
focus on logic rather than underlying details.

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16. GUI Development:Python supports the development of graphical user interface (GUI)
applications through libraries such as Tkinter, PyQt, and wxPython.