Why serial communication connects to external devices in Raspberry Pi - See It in Action

Why Serial Communication Connects to External Devices

📖 Scenario: You have a Raspberry Pi and want to talk to an external device like a sensor or a microcontroller. You use serial communication to send and receive messages between the Raspberry Pi and the device.

🎯 Goal: Build a simple Python program that sets up serial communication parameters and sends a message to an external device connected via serial port.

📋 What You'll Learn

Create a variable with the serial port name

Create a variable with the baud rate (speed of communication)

Write code to open the serial connection using pyserial

Send a message string to the external device

Print confirmation that the message was sent

💡 Why This Matters

🌍 Real World

Serial communication is used to connect Raspberry Pi to sensors, microcontrollers, and other devices to exchange data simply and reliably.

💼 Career

Understanding serial communication is important for hardware interfacing roles, embedded systems programming, and IoT device development.

1

Set up the serial port variable

Create a variable called serial_port and set it to the string "/dev/ttyUSB0" which is the serial port name for the external device.

Raspberry Pi

# Create a variable called serial_port and set it to "/dev/ttyUSB0"
# Your code here

Hint

The serial port is usually a device file like "/dev/ttyUSB0" on Linux systems like Raspberry Pi.

2

Set the baud rate for communication

Create a variable called baud_rate and set it to the integer 9600, which is a common speed for serial communication.

Raspberry Pi

serial_port = "/dev/ttyUSB0"
# Create a variable called baud_rate and set it to 9600
# Your code here

Hint

Baud rate is the speed of data transfer. 9600 is a standard value.

3

Open the serial connection and send a message

Import the serial module. Then create a Serial object called ser using serial.Serial(serial_port, baud_rate). Use ser.write() to send the byte string b'Hello Device' to the external device.

Raspberry Pi

serial_port = "/dev/ttyUSB0"
baud_rate = 9600
# Import serial and open connection
# Send b'Hello Device' to the external device
# Your code here

Hint

Use import serial and then serial.Serial() to open the port. Use write() to send bytes.

4

Print confirmation message

Write a print statement that outputs the exact text "Message sent to device on /dev/ttyUSB0" to confirm the message was sent.

Raspberry Pi

import serial

serial_port = "/dev/ttyUSB0"
baud_rate = 9600

ser = serial.Serial(serial_port, baud_rate)
ser.write(b'Hello Device')
# Print confirmation message
# Your code here

Hint

Use print() with the exact message to show confirmation.