Why ADC is needed in Embedded C - See It in Action

Why ADC is Needed in Embedded Systems

📖 Scenario: Imagine you are building a simple embedded system that reads temperature from a sensor. The sensor gives an analog voltage that changes with temperature. Your microcontroller can only understand digital numbers, not analog voltages.

🎯 Goal: You will create a small program that shows why an Analog-to-Digital Converter (ADC) is needed to read analog sensor values and convert them into digital numbers your microcontroller can use.

📋 What You'll Learn

Create a variable to represent an analog voltage value from a sensor

Create a variable to represent the ADC resolution (number of bits)

Write a function to convert the analog voltage to a digital number using the ADC resolution

Print the digital value to show the conversion result

💡 Why This Matters

🌍 Real World

Embedded systems often read sensors that output analog signals. ADC converts these signals to digital so microcontrollers can process them.

💼 Career

Understanding ADC is essential for embedded developers working with sensors, IoT devices, and hardware interfacing.

1

Create an analog voltage variable

Create a float variable called analog_voltage and set it to 2.5 to represent the sensor voltage in volts.

Embedded C

# Create a float variable called analog_voltage and set it to 2.5
# Your code here

Need a hint?

Use float analog_voltage = 2.5f; to store the voltage.

2

Set ADC resolution

Create an int variable called adc_resolution and set it to 10 to represent a 10-bit ADC.

Embedded C

float analog_voltage = 2.5f;
// Create an int variable called adc_resolution and set it to 10
# Your code here

Need a hint?

Use int adc_resolution = 10; to set the ADC bits.

3

Write ADC conversion function

Write a function called convert_adc that takes float voltage and int resolution as inputs and returns an int digital value. Use the formula: digital_value = (voltage / 5.0) * (2^resolution - 1).

Embedded C

float analog_voltage = 2.5f;
int adc_resolution = 10;

// Write int convert_adc(float voltage, int resolution) function here
# Your code here

Need a hint?

Use bit shift (1 << resolution) to calculate max digital value.

4

Print the ADC conversion result

Call convert_adc with analog_voltage and adc_resolution, store the result in digital_value, and print it using printf.

Embedded C

float analog_voltage = 2.5f;
int adc_resolution = 10;

int convert_adc(float voltage, int resolution) {
    int max_digital = (1 << resolution) - 1;
    int digital_value = (int)((voltage / 5.0f) * max_digital);
    return digital_value;
}

// Call convert_adc and print the digital value
# Your code here

Need a hint?

Use printf("Digital value: %d\n", digital_value); to print.