Multi-channel ADC scanning in Embedded C - Mini Project: Build & Apply

Multi-channel ADC scanning

📖 Scenario: You are working with a microcontroller that reads analog signals from multiple sensors. These sensors are connected to different ADC channels. You want to write a program that reads all these channels one by one and stores their values.

🎯 Goal: Build a simple multi-channel ADC scanning program in C that reads values from 4 ADC channels and stores them in an array.

📋 What You'll Learn

Create an array to store ADC channel numbers

Create an array to store ADC readings

Write a loop to scan each ADC channel

Store the ADC reading for each channel

Print the ADC readings

💡 Why This Matters

🌍 Real World

Multi-channel ADC scanning is used in embedded systems to read sensors like temperature, light, or pressure from multiple inputs.

💼 Career

Embedded software engineers often write code to read and process sensor data from ADC channels for devices like IoT sensors, automotive systems, and industrial controllers.

1

Setup ADC channel array

Create an integer array called adc_channels with these exact values: 0, 1, 2, 3 representing the ADC channels to scan.

Embedded C

# Create an integer array called adc_channels with values 0, 1, 2, 3
// Your code here

Need a hint?

Use curly braces to list the channel numbers inside the array.

2

Setup ADC readings array

Create an integer array called adc_readings with size 4 to store the readings from each ADC channel.

Embedded C

int adc_channels[4] = {0, 1, 2, 3};
// Create an integer array called adc_readings with size 4
// Your code here

Need a hint?

Declare the array without initializing values.

3

Scan ADC channels and store readings

Write a for loop using int i from 0 to 3. Inside the loop, call the function read_adc(adc_channels[i]) and store the result in adc_readings[i]. Assume read_adc(int channel) is a function that returns an integer ADC value for the given channel.

Embedded C

int adc_channels[4] = {0, 1, 2, 3};
int adc_readings[4];
// Write a for loop to scan each ADC channel and store the reading
// Your code here

Need a hint?

Use the loop variable i to index both arrays.

4

Print ADC readings

Write a for loop using int i from 0 to 3. Inside the loop, print the channel number and its ADC reading using printf in this exact format: Channel 0: 1234 where 0 is the channel and 1234 is the reading from adc_readings[i].

Embedded C

int adc_channels[4] = {0, 1, 2, 3};
int adc_readings[4];
for (int i = 0; i < 4; i++) {
    adc_readings[i] = read_adc(adc_channels[i]);
}
// Print each channel and its reading
// Your code here

Need a hint?

Use printf("Channel %d: %d\n", adc_channels[i], adc_readings[i]); inside the loop.