Writing commands to I2C device in Raspberry Pi - Mini Project: Build & Apply

Writing commands to I2C device

📖 Scenario: You have a Raspberry Pi connected to a small I2C device, like a sensor or a display. You want to send commands to this device to control it or request data.In this project, you will learn how to write commands to an I2C device using Python on the Raspberry Pi.

🎯 Goal: Build a simple Python program that writes specific command bytes to an I2C device at a given address.

📋 What You'll Learn

Use the smbus2 library to communicate over I2C

Set the I2C device address correctly

Write a command byte to the device

Print confirmation of the command sent

💡 Why This Matters

🌍 Real World

Many sensors and small devices use I2C to communicate. Writing commands lets you control these devices, like turning on a display or starting a sensor measurement.

💼 Career

Understanding I2C communication is important for embedded systems, hardware interfacing, and IoT jobs where you connect software to physical devices.

1

Set up the I2C bus and device address

Import the SMBus class from the smbus2 library. Create a variable called bus that opens I2C bus number 1. Create a variable called device_address and set it to 0x40 (the device's I2C address).

Raspberry Pi

from smbus2 import SMBus
# Your code here

Hint

Use SMBus(1) to open the I2C bus on Raspberry Pi.

The device address is a hexadecimal number 0x40.

2

Define the command byte to send

Create a variable called command and set it to the integer 0x10. This represents the command byte you want to send to the device.

Raspberry Pi

from smbus2 import SMBus
bus = SMBus(1)
device_address = 0x40
# Your code here

Hint

The command is a single byte, so use an integer like 0x10.

3

Write the command byte to the I2C device

Use the write_byte method of bus to send the command byte to the device_address.

Raspberry Pi

from smbus2 import SMBus
bus = SMBus(1)
device_address = 0x40
command = 0x10
# Your code here

Hint

Call bus.write_byte(device_address, command) to send the command.

4

Print confirmation of the command sent

Write a print statement that outputs: "Command 0x10 sent to device at address 0x40".

Raspberry Pi

from smbus2 import SMBus
bus = SMBus(1)
device_address = 0x40
command = 0x10
bus.write_byte(device_address, command)
# Your code here

Hint

Use print("Command 0x10 sent to device at address 0x40") exactly.