Reading sensor data over I2C in Raspberry Pi - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the I2C library.

Raspberry Pi

import [1]

Drag options to blanks, or click blank then click option'

Asmbus2

Brandom

Ctime

Dos

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unrelated modules like random or os.

Forgetting to import the I2C communication library.

We use the smbus2 library to communicate over I2C on Raspberry Pi.

2fill in blank

medium

Complete the code to create an I2C bus object.

Raspberry Pi

bus = smbus2.SMBus([1])

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A0

B1

C2

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using bus number 0 which may not be enabled.

Using bus numbers higher than 1 without checking hardware.

On Raspberry Pi, I2C bus 1 is commonly used for sensor communication.

3fill in blank

hard

Fix the error in reading a byte from the sensor at address 0x48.

Raspberry Pi

data = bus.read_byte_data([1], 0x00)

Drag options to blanks, or click blank then click option'

A0x48

B0x00

C0x04

D0x49

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong I2C address causing no response or errors.

Confusing register address with device address.

The sensor's I2C address is 0x48, so we must use that address to read data.

4fill in blank

hard

Fill both blanks to read two bytes and combine them into a 16-bit value.

Raspberry Pi

high = bus.read_byte_data(0x48, [1])
low = bus.read_byte_data(0x48, [2])
value = (high << 8) | low

Drag options to blanks, or click blank then click option'

A0x00

B0x01

C0x02

D0x03

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect register addresses causing wrong data.

Mixing up high and low byte registers.

Register 0x00 is usually the high byte and 0x01 the low byte for sensor data.

5fill in blank

hard

Fill all three blanks to convert the raw sensor value to temperature in Celsius.

Raspberry Pi

if value & [1]:
    value = value - [2]
temperature = value * [3]

Drag options to blanks, or click blank then click option'

A0x8000

B65536

C0.0078125

D0x7FFF

Attempts:

3 left

💡 Hint

Common Mistakes

Ignoring sign bit causing wrong negative temperature.

Using wrong scale factor leading to incorrect Celsius values.

The highest bit (0x8000) indicates negative temperature in two's complement. We subtract 65536 to convert. The scale factor 0.0078125 converts raw units to Celsius.