Why ADC is needed in Embedded C

Introduction

ADC (Analog to Digital Converter) is needed to change real-world signals like temperature or sound into numbers a microcontroller can understand.

Reading temperature from a sensor that gives voltage output.

Measuring light intensity using a photoresistor.

Detecting sound levels from a microphone.

Monitoring battery voltage in a device.

Syntax

Embedded C

int adc_value = ADC_Read(channel);

This function reads the analog voltage on the specified channel and returns a digital number.

The digital number represents the voltage level as a value between 0 and the ADC's maximum (like 1023 for 10-bit ADC).

Examples

Reads analog value from channel 0, often connected to a temperature sensor.

Embedded C

int temperature = ADC_Read(0);

Reads analog value from channel 1, for example from a light sensor.

Embedded C

int light_level = ADC_Read(1);

Sample Program

This program simulates reading analog values from two sensors using ADC and prints the digital values.

Embedded C

#include <stdio.h>

// Simulated ADC read function
int ADC_Read(int channel) {
    if (channel == 0) return 512; // Example value for temperature sensor
    if (channel == 1) return 256; // Example value for light sensor
    return 0;
}

int main() {
    int temp = ADC_Read(0);
    int light = ADC_Read(1);
    printf("Temperature sensor value: %d\n", temp);
    printf("Light sensor value: %d\n", light);
    return 0;
}

Important Notes

ADC converts continuous voltage into a number so microcontrollers can process it.

Different ADCs have different resolutions, like 8-bit, 10-bit, or 12-bit, affecting precision.

Summary

ADC is needed to turn real-world analog signals into digital numbers.

This lets microcontrollers read sensors like temperature or light.

Without ADC, microcontrollers cannot understand analog signals.