Reading Analog Values with Arduino Nano Multiplexer

How to Read Analog Values from a 12-Channel IR Sensor Array using an Arduino Nano

This tutorial will guide you through the process of reading analog values from a 12-channel IR sensor array using an Arduino Nano and a 16-channel multiplexer module. This project is perfect for robotics enthusiasts or those exploring electronics.

Hardware Requirements

• Arduino Nano
• 16-channel 74HC4067 multiplexer module
• Breadboard
• 12-channel IR sensor array (custom-made or ordered)

Connections

1. Place the Arduino Nano on the breadboard.
2. Connect the 5-volt output pin of the Arduino to the positive rail of the breadboard, and the ground pin to the negative rail.
3. Place the multiplexer module on the breadboard.
4. Connect the VCC pin of the module to the positive rail, and the ground pin to the negative rail.
5. Connect the enable pin of the multiplexer to the negative rail to activate it.
6. Connect the multiplexer signal pin to one of the Arduino's analog pins according to the pin mapping table.
7. Connect the sensor pins to the multiplexer's output pins from 0 to 11 in sequence.
8. Finally, connect the sensor ground to the breadboard's negative rail and the sensor VCC to the positive rail.

Software Requirements

• Arduino IDE software

Code Explanation

2. Create an array named sensor of size 12 to store the analog readings for up to 12 channels from the multiplexer.
3. Initialize serial communication at a baud rate of 9600 for debugging purposes.
4. Configure the single pin connected to the Arduino as an output to control the multiplexer.
5. The select channel function configures the multiplexer to select the desired channel by setting the control pins based on the binary representation of the channel number.

Code

const int signalPin = A0; // Define the signal pin
int sensor[12]; // Create an array to store analog readings

void setup() {
  Serial.begin(9600); // Initialize serial communication
  pinMode(signalPin, OUTPUT); // Configure the signal pin as an output
}

void loop() {
  for (int i = 0; i < 12; i++) { // Iterate through channels 0 to 11
    selectChannel(i); // Select the channel on the multiplexer
    sensor[i] = analogRead(signalPin); // Read the analog signal from the selected channel and store it in the sensor array
    Serial.print(sensor[i]); // Print the sensor reading for the current channel to the serial monitor
    Serial.print(" "); // Separate readings with spaces
  }
  Serial.println(); // New line after readings for all channels are sent
}

void selectChannel(int channel) {
  // Configure the multiplexer to select the desired channel by setting the control pins based on the binary representation of the channel number
}
      

Testing and Results

Open the serial monitor to display the sensor values. When you keep your hand on the sensor, the value will be less than 100. Otherwise, the value will be greater than 800 or 900.

You can extend the channel up to 16 channels by changing the code.

Introduction

Hardware Requirements

• An Arduino Nano board
• A multiplexer module (such as the CD74HC4067)
• Multiple analog sensors (such as potentiometers or light-dependent resistors)
• Jumper wires and a breadboard for connection

Multiplexer Basics

The CD74HC4067 is a 16-channel multiplexer module that can be controlled using four digital pins on the Arduino. By setting these control pins high or low, we can select which of the 16 inputs is connected to the output.

Connecting the Multiplexer

1. Connect the VCC pin on the multiplexer to the 5V pin on the Arduino.
2. Connect the GND pin on the multiplexer to a GND pin on the Arduino.
3. Connect the S0-S3 pins on the multiplexer to digital pins 2-5 on the Arduino (respectively).
4. Connect the analog sensors you wish to read from to the input channels on the multiplexer (e.g. CH0, CH1, etc.).

Reading Analog Values with Arduino

const int muxS0 = 2; // S0 pin on the multiplexer
const int muxS1 = 3; // S1 pin on the multiplexer
const int muxS2 = 4; // S2 pin on the multiplexer
const int muxS3 = 5; // S3 pin on the multiplexer
const int analogInPin = A0; // Analog input pin on the Arduino

void setup() {
  pinMode(muxS0, OUTPUT);
  pinMode(muxS1, OUTPUT);
  pinMode(muxS2, OUTPUT);
  pinMode(muxS3, OUTPUT);
}

void loop() {
  for (int i = 0; i < 16; i++) { // Loop through each of the 16 channels
    // Set the control pins to select the current channel
    digitalWrite(muxS0, bitRead(i, 0));
    digitalWrite(muxS1, bitRead(i, 1));
    digitalWrite(muxS2, bitRead(i, 2));
    digitalWrite(muxS3, bitRead(i, 3));

    // Read the analog value from the selected channel
    int sensorValue = analogRead(analogInPin);

    // Print the result to the serial monitor
    Serial.print("Channel ");
    Serial.print(i);
    Serial.print(": ");
    Serial.println(sensorValue);

    delay(100); // Wait 100ms before moving on to the next channel
  }
}
      

Conclusion

const int muxSelectPins[] = {2, 3, 4}; // S0-S2 pins
void setup() {
  pinMode(muxSelectPins[0], OUTPUT);
  pinMode(muxSelectPins[1], OUTPUT);
  pinMode(muxSelectPins[2], OUTPUT);
}

void loop() {
  int channel = 0; // Select MUX channel
  digitalWrite(muxSelectPins[0], (channel & 1));
  digitalWrite(muxSelectPins[1], ((channel >> 1) & 1));
  digitalWrite(muxSelectPins[2], ((channel >> 2) & 1));
  int sensorValue = analogRead(A0); // Read analog value from MUX output
  Serial.println(sensorValue);
}