QTRMuxes

Lightweight Arduino library for reading Analog Pololu QTR sensors using one or two CD74HC4067 multiplexers.

Supports single and dual 16-channel mux setups (up to 32 sensors), sensor calibration, raw and calibrated readings, and line position calculation.

Features

• Single or dual CD74HC4067 mux support
• Calibration routine with multiple samples
• Read raw sensor values
• Read calibrated sensor values (mapped 0–1000)
• Calculate line position from sensor readings
• Simple API similar to Pololu QTRSensors

Dependencies

This library depends on the CD74HC4067 library by waspinator.
Install it using the Arduino Library Manager or manually from the GitHub repository.

Installation

1. Download or clone this repository.
2. Place the QTRMuxes folder in your Arduino libraries directory.
3. Make sure the CD74HC4067 library is installed.
4. Restart Arduino IDE.

Usage

See the examples for usage with single or dual mux.

Basic example snippet:

#include <QTRMuxes.h>

#define S0 2
#define S1 3
#define S2 4
#define S3 5
#define SIG A0
#define EN0 6
#define EN1 7
#define SENSOR_COUNT 31

QTRMuxes qtr(S0, S1, S2, S3, SIG, EN0, EN1, SENSOR_COUNT);

void setup() {
  Serial.begin(115200);
  qtr.begin(dualMux);
  Serial.println("Calibrating sensors...");
  qtr.calibrate(20, dualMux);
  Serial.println("Calibration done.");
}

void loop() {
  uint16_t sensorValues[SENSOR_COUNT];
  qtr.readCalibrated(sensorValues, dualMux);

  for (int i = 0; i < SENSOR_COUNT; i++) {
    Serial.print(sensorValues[i]);
    Serial.print('\t');
  }
  Serial.println();

  int position = qtr.readLine(sensorValues, dualMux);
  Serial.print("Line position: ");
  Serial.println(position);

  delay(100);
}