Setting pin mode (IN, OUT) in Raspberry Pi - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set GPIO pin 17 as an output.

Raspberry Pi

GPIO.setup(17, GPIO.[1])

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

AOUT

BHIGH

CLOW

DIN

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'IN' instead of 'OUT' when setting output mode.

Confusing pin mode with pin state (HIGH/LOW).

To set a pin as output, use GPIO.OUT.

2fill in blank

medium

Complete the code to set GPIO pin 22 as an input.

Raspberry Pi

GPIO.setup(22, GPIO.[1])

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

AOUT

BIN

CHIGH

DLOW

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'OUT' instead of 'IN' when setting input mode.

Confusing pin mode with pin state.

To read signals from a pin, set it as input using GPIO.IN.

3fill in blank

hard

Fix the error in setting pin 5 mode to output.

Raspberry Pi

GPIO.setup(5, GPIO.[1])

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

AINPUT

BIN

COUTPUT

DOUT

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'OUTPUT' instead of 'OUT'.

Using 'INPUT' instead of 'IN'.

The correct constant for output mode is GPIO.OUT, not 'OUTPUT'.

4fill in blank

hard

Fill both blanks to set pin 13 as input with a pull-up resistor.

Raspberry Pi

GPIO.setup(13, GPIO.[1], pull_up_down=GPIO.[2])

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

AIN

BOUT

CPUD_UP

DPUD_DOWN

Attempts:

3 left

💡 Hint

Common Mistakes

Using output mode instead of input.

Using pull-down resistor instead of pull-up.

Set pin mode to GPIO.IN and enable pull-up resistor with GPIO.PUD_UP.

5fill in blank

hard

Fill all three blanks to set pin 18 as output and set it HIGH.

Raspberry Pi

GPIO.setup(18, GPIO.[1])
GPIO.output(18, GPIO.[2])
state = GPIO.input(18) == GPIO.[3]

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

AIN

BOUT

CHIGH

DLOW

Attempts:

3 left

💡 Hint

Common Mistakes

Using input mode instead of output.

Setting pin state to LOW instead of HIGH.

Comparing input to LOW instead of HIGH.

Set pin 18 as output with GPIO.OUT, set it HIGH, and check if input reads HIGH.

Practice

1. What does GPIO.setup(pin, GPIO.IN) do in Raspberry Pi programming?

easy

A. Sets the pin as an input to read signals

B. Sets the pin as an output to send signals

C. Resets the pin to default mode

D. Disables the pin

Solution

1. Step 1: Understand the function purpose

   GPIO.setup configures a pin's mode on the Raspberry Pi.

2. Step 2: Identify the mode set by GPIO.IN

   GPIO.IN sets the pin to input mode, allowing it to read signals.

3. Final Answer:

   Sets the pin as an input to read signals -> Option A

4. Quick Check:

   GPIO.IN means input mode [OK]

Hint: IN means input mode to read signals [OK]

Common Mistakes:

• Confusing IN with OUT mode
• Thinking it resets or disables the pin
• Assuming it sets output mode

2. Which of the following is the correct syntax to set GPIO pin 17 as an output pin?

easy

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

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

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

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

Solution

1. Step 1: Identify the correct function to set pin mode

   GPIO.setup(pin, mode) is used to set pin mode.

2. Step 2: Choose the correct mode for output

   GPIO.OUT sets the pin as output.

3. Final Answer:

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

4. Quick Check:

   Use setup with OUT for output pins [OK]

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

Common Mistakes:

• Using GPIO.output instead of GPIO.setup to set mode
• Confusing GPIO.setmode with GPIO.setup
• Setting pin as input instead of output

3. What will be the output of this code snippet?

import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(22, GPIO.OUT)
GPIO.output(22, True)
print(GPIO.input(22))

medium

A. None

B. True

C. Error: Pin not set as input

D. False

Solution

1. Step 1: Understand pin mode and output

   Pin 22 is set as output and then set to True (high voltage).

2. Step 2: Reading pin state with GPIO.input

   Reading the pin returns the current output state, which is True.

3. Final Answer:

   True -> Option B

4. Quick Check:

   Output pin set True reads as True [OK]

Hint: Output pin set True reads True when input read [OK]

Common Mistakes:

• Thinking input read only works on input pins
• Expecting False because pin is output
• Assuming error when reading output pin

4. Identify the error in this code snippet:

import RPi.GPIO as GPIO
GPIO.setup(5, GPIO.OUT)
GPIO.output(5, True)

medium

A. Missing GPIO.setmode() before setup

B. Wrong pin number used

C. GPIO.output() cannot set pin high

D. GPIO.setup() should use GPIO.IN

Solution

1. Step 1: Check for GPIO mode setting

   GPIO.setmode() must be called before setup to define pin numbering scheme.

2. Step 2: Verify setup and output usage

   Setup and output calls are correct but missing mode causes runtime error.

3. Final Answer:

   Missing GPIO.setmode() before setup -> Option A

4. Quick Check:

   Always call GPIO.setmode() first [OK]

Hint: Always call GPIO.setmode() before setup [OK]

Common Mistakes:

• Skipping GPIO.setmode() call
• Confusing setup and output functions
• Using wrong pin numbering without setmode

5. You want to read a button press on pin 10 and turn on an LED on pin 11 when pressed. Which code correctly sets the pin modes?

hard

A. GPIO.setup(10, GPIO.OUT)
GPIO.setup(11, GPIO.IN)

B. GPIO.setup(10, GPIO.IN)
GPIO.setup(11, GPIO.IN)

C. GPIO.setup(10, GPIO.IN)
GPIO.setup(11, GPIO.OUT)

D. GPIO.setup(10, GPIO.OUT)
GPIO.setup(11, GPIO.OUT)

Solution

1. Step 1: Determine pin roles

   Pin 10 reads button input, so it must be input mode.

2. Step 2: Set LED pin mode

   Pin 11 controls LED output, so it must be output mode.

3. Final Answer:

   GPIO.setup(10, GPIO.IN) GPIO.setup(11, GPIO.OUT) -> Option C

4. Quick Check:

   Input pin for button, output pin for LED [OK]

Hint: Input for button pin, output for LED pin [OK]

Common Mistakes:

• Reversing input and output pins
• Setting both pins as input
• Setting both pins as output