MCP3008 ADC over SPI in Raspberry Pi - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the SPI library needed to communicate with MCP3008.

Raspberry Pi

import [1]

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Agpiozero

Bspidev

CRPi.GPIO

Dtime

Attempts:

3 left

💡 Hint

Common Mistakes

Importing gpiozero or RPi.GPIO instead of spidev.

Forgetting to import the SPI library.

The spidev library is used to communicate over SPI with devices like the MCP3008 ADC.

2fill in blank

medium

Complete the code to open SPI bus 0, device 0 for communication.

Raspberry Pi

spi = spidev.SpiDev()
spi.[1](0, 0)

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Aopen

Bstart

Cconnect

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using connect or init instead of open.

Not opening the SPI device before use.

The open method opens the SPI bus and device for communication.

3fill in blank

hard

Fix the error in the code to read channel 0 from MCP3008 correctly.

Raspberry Pi

def read_channel(channel):
    adc = spi.xfer2([1, (8 + [1]) << 4, 0])
    data = ((adc[1] & 3) << 8) + adc[2]
    return data

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Aspi

B0

C1

Dchannel

Attempts:

3 left

💡 Hint

Common Mistakes

Using a fixed number like 0 or 1 instead of the channel variable.

Using an undefined variable.

The variable channel must be used to select the ADC channel dynamically.

4fill in blank

hard

Fill both blanks to set SPI speed and mode correctly for MCP3008.

Raspberry Pi

spi.max_speed_hz = [1]
spi.mode = [2]

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A1350000

B500000

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using too high or too low SPI speed.

Setting wrong SPI mode causing communication errors.

The MCP3008 works well with SPI speed of 1.35 MHz and SPI mode 0.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that reads channels 0 to 3 and stores their values.

Raspberry Pi

adc_values = {ch: read_channel([1]) for ch in range([2], [3])}

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Ach

B0

C4

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a fixed number instead of the loop variable for reading channels.

Incorrect range boundaries causing missing or extra channels.

The comprehension uses ch as the argument to read_channel and loops from 0 to 4 (exclusive) to read channels 0,1,2,3.