Automated plant watering system in Raspberry Pi - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the GPIO library for Raspberry Pi.

Raspberry Pi

import [1] as GPIO

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

ARPi.GPIO

Bgpiozero

Ctime

Dos

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unrelated libraries like 'time' or 'os'.

Using 'gpiozero' which is a different GPIO library.

The RPi.GPIO library is used to control GPIO pins on Raspberry Pi.

2fill in blank

medium

Complete the code to set GPIO pin 18 as an output pin.

Raspberry Pi

GPIO.setmode(GPIO.BCM)
GPIO.setup([1], GPIO.OUT)

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

A17

B18

C27

D22

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong pin numbers like 17 or 22.

Not setting the pin as output.

Pin 18 is set as output to control the water pump.

3fill in blank

hard

Fix the error in the code to read moisture sensor value from pin 23.

Raspberry Pi

GPIO.setup(23, GPIO.IN)
moisture = GPIO.[1](23)

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

Aoutput

Bread

Cinput

Dinput_read

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'output' instead of 'input'.

Using non-existent methods like 'read' or 'input_read'.

Use GPIO.input(pin) to read digital input from a pin.

4fill in blank

hard

Fill both blanks to turn on the water pump when soil is dry.

Raspberry Pi

if moisture [1] 0:
    GPIO.output([2], GPIO.HIGH)

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

A==

B!=

C18

D23

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '=='.

Using wrong pin number for pump.

If moisture sensor reads 0 (dry), turn on pump at pin 18.

5fill in blank

hard

Fill both blanks to create a dictionary of sensor readings with pin as key and value as moisture.

Raspberry Pi

sensor_data = {[2]: [1] for [3] in [23, 24, 25]}

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

A{

BGPIO.input(pin)

Cpin

D}

Attempts:

3 left

💡 Hint

Common Mistakes

Using list brackets instead of dictionary braces.

Using wrong variable names.

This dictionary comprehension reads moisture from pins 23, 24, and 25.

Practice

1.

What is the main purpose of an automated plant watering system using a Raspberry Pi?

easy

A. To control room temperature automatically

B. To water plants continuously without checking soil

C. To measure sunlight for plants

D. To water plants only when the soil is dry

Solution

1. Step 1: Understand the system goal

   The system uses sensors to check soil moisture.

2. Step 2: Identify the watering condition

   It waters plants only when soil is dry to save water.

3. Final Answer:

   To water plants only when the soil is dry -> Option D

4. Quick Check:

   Water only if dry = A [OK]

Hint: Focus on saving water by watering only when needed [OK]

Common Mistakes:

• Thinking it waters plants all the time
• Confusing soil moisture with sunlight
• Assuming it controls temperature

2.

Which of the following Python code snippets correctly sets up a GPIO pin 17 as an output to control a water pump?

import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
# What goes here?

easy

A. GPIO.setup(17, GPIO.OUT)

B. GPIO.setup(17, GPIO.IN)

C. GPIO.output(17, GPIO.IN)

D. GPIO.output(17, GPIO.OUT)

Solution

1. Step 1: Identify pin mode setup

   GPIO.setup(pin_number, GPIO.OUT) sets pin as output.

2. Step 2: Choose correct function and mode

   GPIO.setup(17, GPIO.OUT) correctly sets pin 17 as output.

3. Final Answer:

   GPIO.setup(17, GPIO.OUT) -> Option A

4. Quick Check:

   Setup output pin = A [OK]

Hint: Use GPIO.setup(pin, GPIO.OUT) to set output pins [OK]

Common Mistakes:

• Using GPIO.IN instead of GPIO.OUT for output pins
• Calling GPIO.output instead of GPIO.setup to set mode
• Confusing pin numbers or modes

3.

What will be the output of this Python code controlling a pump based on soil moisture sensor reading?

import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.OUT)
soil_moisture = 300  # sensor value
if soil_moisture < 400:
    GPIO.output(17, GPIO.HIGH)
    print("Pump ON")
else:
    GPIO.output(17, GPIO.LOW)
    print("Pump OFF")

medium

A. SyntaxError

B. Pump OFF

C. Pump ON

D. No output

Solution

1. Step 1: Check soil moisture condition

   Value 300 is less than 400, so condition is true.

2. Step 2: Determine pump action and output

   GPIO.output sets pin HIGH and prints "Pump ON".

3. Final Answer:

   Pump ON -> Option C

4. Quick Check:

   300 < 400 triggers Pump ON [OK]

Hint: Compare sensor value to threshold to decide pump state [OK]

Common Mistakes:

• Misreading the comparison operator
• Confusing HIGH and LOW states
• Ignoring print output

4.

Identify the error in this Raspberry Pi watering system code snippet:

import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.OUT)
soil_moisture = 500
if soil_moisture > 400
    GPIO.output(17, GPIO.LOW)
    print("Pump OFF")

medium

A. soil_moisture value is invalid

B. Missing colon (:) after if condition

C. GPIO.output should be GPIO.setup

D. Wrong GPIO pin number

Solution

1. Step 1: Check if statement syntax

   Python requires a colon (:) after the if condition.

2. Step 2: Identify missing colon error

   The code misses ':' after 'if soil_moisture > 400', causing syntax error.

3. Final Answer:

   Missing colon (:) after if condition -> Option B

4. Quick Check:

   if statement needs ':' = D [OK]

Hint: Always put ':' after if conditions in Python [OK]

Common Mistakes:

• Forgetting colon after if
• Confusing GPIO.output with GPIO.setup
• Assuming pin number is wrong

5.

You want to improve the watering system to water plants only if soil moisture is below 400 and only between 6 AM and 8 AM. Which Python code snippet correctly adds this time condition?

import datetime
now = datetime.datetime.now()
soil_moisture = 350
if soil_moisture < 400 and ???:
    print("Watering plants")
else:
    print("No watering")

hard

A. now.hour >= 6 and now.hour <= 8

B. now.hour > 6 or now.hour < 8

C. now.hour < 6 and now.hour > 8

D. now.hour == 6 or now.hour == 8

Solution

1. Step 1: Understand time range condition

   We want hours from 6 to 8 inclusive, so hour >= 6 and hour <= 8.

2. Step 2: Combine soil moisture and time conditions

   Use 'and' to check both soil moisture and time range.

3. Final Answer:

   now.hour >= 6 and now.hour <= 8 -> Option A

4. Quick Check:

   Check hour between 6 and 8 = B [OK]

Hint: Use 'and' with hour >= 6 and <= 8 for time range [OK]

Common Mistakes:

• Using 'or' instead of 'and' for time range
• Using strict inequalities excluding 6 or 8
• Checking only exact hours 6 or 8