ADC interrupt-driven reading in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable the ADC.

Embedded C

ADC->CR2 |= [1];

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AADC_CR2_CONT

BADC_CR2_ADON

CADC_CR2_DMA

DADC_CR2_EOCS

Attempts:

3 left

💡 Hint

Common Mistakes

Using ADC_CR2_CONT which enables continuous mode but not interrupt.

Using ADC_CR2_DMA which enables DMA, not interrupt.

Using ADC_CR2_EOCS which configures end of conversion selection.

The ADC_CR2_ADON bit enables the ADC.

2fill in blank

medium

Complete the code to start the ADC conversion.

Embedded C

ADC->CR2 |= [1];

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AADC_CR2_SWSTART

BADC_CR2_ADON

CADC_CR2_EXTTRIG

DADC_CR2_DMA

Attempts:

3 left

💡 Hint

Common Mistakes

Using ADC_CR2_ADON which only enables ADC but does not start conversion.

Using ADC_CR2_EXTTRIG which is for external trigger, not software start.

Using ADC_CR2_DMA which enables DMA, unrelated to start.

ADC_CR2_SWSTART starts the ADC conversion by software.

3fill in blank

hard

Fix the error in the interrupt handler to clear the ADC interrupt flag.

Embedded C

void ADC_IRQHandler(void) {
    if (ADC->SR & [1]) {
        uint16_t value = ADC->DR;
        // process value
        ADC->SR &= ~ADC_SR_EOC;
    }
}

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AADC_SR_EOC

BADC_SR_STRT

CADC_SR_AWD

DADC_SR_OVR

Attempts:

3 left

💡 Hint

Common Mistakes

Checking ADC_SR_OVR which is overrun flag, not conversion complete.

Checking ADC_SR_AWD which is analog watchdog flag.

Checking ADC_SR_STRT which is start flag, not end.

ADC_SR_EOC is the end of conversion flag that must be checked and cleared.

4fill in blank

hard

Fill both blanks to configure the NVIC for ADC interrupt with priority 1.

Embedded C

NVIC_SetPriority([1], 1);
NVIC_EnableIRQ([2]);

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AADC_IRQn

BTIM2_IRQn

CUSART1_IRQn

DEXTI0_IRQn

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated IRQ numbers like TIM2_IRQn or USART1_IRQn.

Mismatching IRQ numbers between priority and enable calls.

ADC_IRQn is the interrupt number for ADC; both priority and enable use it.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that stores ADC values for channels with readings above 1000.

Embedded C

adc_values = { [1]: [2] for [3] in channels if readings[[3]] > 1000 }

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Achannel

Breadings[channel]

D{

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the opening brace.

Using wrong variable names for keys or values.

Incorrect comprehension syntax.

The dictionary comprehension syntax requires braces, key:value pairs, and iteration variable.