smbus2 library for I2C in Raspberry Pi - Mini Project: Build & Apply

Reading Temperature Sensor Data Using smbus2 on Raspberry Pi

📖 Scenario: You have a Raspberry Pi connected to a temperature sensor via the I2C bus. You want to read the temperature data from the sensor using the smbus2 library.

🎯 Goal: Build a Python program that reads raw temperature data from the sensor using smbus2 and prints the temperature value.

📋 What You'll Learn

Use the smbus2 library to communicate over I2C

Create a variable for the I2C bus number

Create a variable for the sensor's I2C address

Read a byte of data from the sensor's temperature register

Print the temperature data read from the sensor

💡 Why This Matters

🌍 Real World

Reading sensor data from devices like temperature sensors, light sensors, or other I2C peripherals connected to Raspberry Pi.

💼 Career

Understanding how to use I2C communication and the smbus2 library is useful for embedded systems, IoT projects, and hardware interfacing jobs.

1

Set up I2C bus and sensor address

Import SMBus from smbus2. Create a variable called bus_number and set it to 1. Create a variable called sensor_address and set it to 0x48.

Raspberry Pi

# Import SMBus and set bus_number and sensor_address
# Your code here

Hint

The Raspberry Pi usually uses I2C bus 1. The sensor address is given in hexadecimal.

2

Set the temperature register address

Create a variable called temp_register and set it to 0x00, which is the register address for temperature data on the sensor.

Raspberry Pi

from smbus2 import SMBus

bus_number = 1
sensor_address = 0x48

# Set the temperature register address
# Your code here

Hint

The temperature register is usually at address 0x00 for many temperature sensors.

3

Read temperature data from the sensor

Open the I2C bus using SMBus(bus_number) as bus. Use bus.read_byte_data(sensor_address, temp_register) to read the temperature byte. Store the result in a variable called temperature.

Raspberry Pi

from smbus2 import SMBus

bus_number = 1
sensor_address = 0x48
temp_register = 0x00

# Read temperature data from the sensor
# Your code here

Hint

Use a with block to open the bus safely. The read_byte_data method reads one byte from the given register.

4

Print the temperature value

Print the value of the temperature variable using print().

Raspberry Pi

from smbus2 import SMBus

bus_number = 1
sensor_address = 0x48
temp_register = 0x00

with SMBus(bus_number) as bus:
    temperature = bus.read_byte_data(sensor_address, temp_register)
    
    # Print the temperature value
    # Your code here

Hint

Use print(temperature) to show the temperature byte read from the sensor.