91 lines
4 KiB
C++
Executable file
91 lines
4 KiB
C++
Executable file
#include <QTRSensors.h>
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// This example is designed for use with six QTR-1A sensors or the first six sensors of a
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// QTR-8A module. These reflectance sensors should be connected to analog inputs 0 to 5.
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// The QTR-8A's emitter control pin (LEDON) can optionally be connected to digital pin 2,
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// or you can leave it disconnected and change the EMITTER_PIN #define below from 2 to
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// QTR_NO_EMITTER_PIN.
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// The setup phase of this example calibrates the sensor for ten seconds and turns on
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// the LED built in to the Arduino on pin 13 while calibration is going on.
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// During this phase, you should expose each reflectance sensor to the lightest and
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// darkest readings they will encounter.
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// For example, if you are making a line follower, you should slide the sensors across the
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// line during the calibration phase so that each sensor can get a reading of how dark the
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// line is and how light the ground is. Improper calibration will result in poor readings.
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// If you want to skip the calibration phase, you can get the raw sensor readings
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// (analog voltage readings from 0 to 1023) by calling qtra.read(sensorValues) instead of
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// qtra.readLine(sensorValues).
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// The main loop of the example reads the calibrated sensor values and uses them to
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// estimate the position of a line. You can test this by taping a piece of 3/4" black
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// electrical tape to a piece of white paper and sliding the sensor across it. It
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// prints the sensor values to the serial monitor as numbers from 0 (maximum reflectance)
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// to 1000 (minimum reflectance) followed by the estimated location of the line as a number
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// from 0 to 5000. 1000 means the line is directly under sensor 1, 2000 means directly
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// under sensor 2, etc. 0 means the line is directly under sensor 0 or was last seen by
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// sensor 0 before being lost. 5000 means the line is directly under sensor 5 or was
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// last seen by sensor 5 before being lost.
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#define NUM_SENSORS 6 // number of sensors used
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#define NUM_SAMPLES_PER_SENSOR 4 // average 4 analog samples per sensor reading
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#define EMITTER_PIN 2 // emitter is controlled by digital pin 2
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// sensors 0 through 5 are connected to analog inputs 0 through 5, respectively
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QTRSensorsAnalog qtra((unsigned char[]) {0, 1, 2, 3, 4, 5},
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NUM_SENSORS, NUM_SAMPLES_PER_SENSOR, EMITTER_PIN);
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unsigned int sensorValues[NUM_SENSORS];
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void setup()
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{
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delay(500);
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pinMode(13, OUTPUT);
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digitalWrite(13, HIGH); // turn on Arduino's LED to indicate we are in calibration mode
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for (int i = 0; i < 400; i++) // make the calibration take about 10 seconds
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{
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qtra.calibrate(); // reads all sensors 10 times at 2.5 ms per six sensors (i.e. ~25 ms per call)
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}
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digitalWrite(13, LOW); // turn off Arduino's LED to indicate we are through with calibration
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// print the calibration minimum values measured when emitters were on
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Serial.begin(9600);
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for (int i = 0; i < NUM_SENSORS; i++)
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{
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Serial.print(qtra.calibratedMinimumOn[i]);
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Serial.print(' ');
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}
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Serial.println();
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// print the calibration maximum values measured when emitters were on
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for (int i = 0; i < NUM_SENSORS; i++)
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{
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Serial.print(qtra.calibratedMaximumOn[i]);
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Serial.print(' ');
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}
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Serial.println();
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Serial.println();
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delay(1000);
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}
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void loop()
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{
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// read calibrated sensor values and obtain a measure of the line position from 0 to 5000
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// To get raw sensor values, call:
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// qtra.read(sensorValues); instead of unsigned int position = qtra.readLine(sensorValues);
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unsigned int position = qtra.readLine(sensorValues);
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// print the sensor values as numbers from 0 to 1000, where 0 means maximum reflectance and
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// 1000 means minimum reflectance, followed by the line position
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for (unsigned char i = 0; i < NUM_SENSORS; i++)
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{
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Serial.print(sensorValues[i]);
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Serial.print('\t');
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}
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//Serial.println(); // uncomment this line if you are using raw values
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Serial.println(position); // comment this line out if you are using raw values
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delay(250);
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}
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