PWM generation using timers in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the timer prescaler for PWM generation.

Embedded C

TIM_HandleTypeDef htim1;

void PWM_Init() {
    htim1.Init.Prescaler = [1];
    // Other initialization code
}

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

A65535

B79

C1000

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 as prescaler causes no division, leading to very fast timer overflow.

The prescaler divides the timer clock. Setting it to 79 divides the clock by 80, which is common for PWM timing.

2fill in blank

medium

Complete the code to set the PWM period by configuring the timer's auto-reload register.

Embedded C

void PWM_Init() {
    htim1.Init.Period = [1];
    // Other initialization code
}

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A999

B79

C10000

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Setting period to 0 disables counting, no PWM generated.

The period value sets the timer overflow count. 999 means the timer counts from 0 to 999, giving 1000 counts per PWM cycle.

3fill in blank

hard

Fix the error in setting the PWM pulse width for 50% duty cycle.

Embedded C

TIM_OC_InitTypeDef sConfigOC = {0};
sConfigOC.Pulse = [1];
// Other PWM channel configuration

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Ahtim1.Init.Period / 2

Bhtim1.Init.Period

Chtim1.Init.Prescaler

Dhtim1.Init.Period * 2

Attempts:

3 left

💡 Hint

Common Mistakes

Using full period as pulse causes 100% duty cycle, no off time.

Pulse value sets the duty cycle. Half of the period gives 50% duty cycle.

4fill in blank

hard

Fill both blanks to configure the timer for PWM mode and enable the preload feature.

Embedded C

sConfigOC.OCMode = [1];
sConfigOC.OCPreload = [2];

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ATIM_OCMODE_PWM1

BTIM_OCMODE_TIMING

CTIM_OCNORELOAD_ENABLE

DTIM_OCPRELOAD_ENABLE

Attempts:

3 left

💡 Hint

Common Mistakes

Using timing mode disables PWM output.

OCMode must be set to PWM1 for PWM output. Preload enable allows updating pulse value safely.

5fill in blank

hard

Fill all three blanks to start the PWM signal on channel 1 and enable the timer.

Embedded C

HAL_TIM_PWM_Start(&htim1, [1]);
__HAL_TIM_ENABLE(&htim1);
__HAL_TIM_SET_COUNTER(&htim1, [2]);
htim1.Instance->CR1 |= [3];

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ATIM_CHANNEL_1

B0

CTIM_CR1_CEN

DTIM_CHANNEL_2

Attempts:

3 left

💡 Hint

Common Mistakes

Starting PWM on wrong channel disables output.

Start PWM on channel 1, reset counter to 0, and enable timer counter by setting CEN bit.