228 lines
9.9 KiB
C++
Executable File
228 lines
9.9 KiB
C++
Executable File
#include <AFMotor.h>
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int trigPin = 10; // Trigger
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int echoPin = 11; // Echo
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long duration, cm, inches;
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#define TRIG_PIN 10 // Pin A4 on the Motor Drive Shield connected to the ultrasonic sensor
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#define ECHO_PIN 11 // Pin A5 on the Motor Drive Shield connected to the ultrasonic sensor
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#define MAX_DISTANCE_POSSIBLE 1000 // sets maximum useable sensor measuring distance to 1000cm
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#define MAX_SPEED 120 // sets speed of DC traction motors to 120/256 or about 47% of full speed - to reduce power draining.
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#define MOTORS_CALIBRATION_OFFSET 3 // this sets offset to allow for differences between the two DC motors
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#define COLL_DIST 20 // sets distance at which the Obstacle avoiding Robot stops and reverses to 10cm
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#define TURN_DIST COLL_DIST+10 // sets distance at which the Obstacle avoiding Robot looks away from object (not reverse) to 20cm (10+10)
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AF_DCMotor leftMotor(1, MOTOR12_1KHZ); // create motor #1 using M1 output on Motor Drive Shield, set to 1kHz PWM frequency
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AF_DCMotor rightMotor(2, MOTOR34_1KHZ); // create motor #2, using M2 output, set to 1kHz PWM frequency
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int pos = 0; // this sets up variables for use in the sketch (code)
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int maxDist = 0;
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int maxAngle = 0;
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int maxRight = 0;
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int maxLeft = 0;
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int maxFront = 0;
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int course = 0;
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int curDist = 0;
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String motorSet = "";
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int speedSet = 0;
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//-------------------------------------------- SETUP LOOP ----------------------------------------------------------------------------
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void setup() {
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Serial.begin(9600);
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//Define inputs and outputs
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pinMode(trigPin, OUTPUT);
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pinMode(echoPin, INPUT);
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delay(2000); // delay for two seconds
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checkRoute(); // run the CheckRoute routine to find the best Route to begin travel
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motorSet = "FORWARD"; // set the director indicator variable to FORWARD
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moveForward(); // run function to make Obstacle avoiding Robot move forward
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}
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//------------------------------------------------------------------------------------------------------------------------------------
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//---------------------------------------------MAIN LOOP ------------------------------------------------------------------------------
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void loop() {
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checkForward(); // check that if the Obstacle avoiding Robot is supposed to be moving forward, that the drive motors are set to move forward - this is needed to overcome some issues with only using 4 AA NiMH batteries
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checkRoute(); // set ultrasonic sensor to scan for any possible obstacles
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void checkRoute() {
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int curLeft = 0;
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int curFront = 0;
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int curRight = 0;
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int curDist = 0;
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delay(120); // wait 120milliseconds for servo to reach position
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for (pos = 144; pos >= 36; pos -= 18) // loop to sweep the servo (& sensor) from 144-degrees left to 36-degrees right at 18-degree intervals.
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{
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delay(90); // wait 90ms for servo to get to position
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checkForward(); // check the Obstacle avoiding Robot is still moving forward
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curDist = readPing(); // get the current distance to any object in front of sensor
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if (curDist < COLL_DIST) { // if the current distance to object is less than the collision distance
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checkCourse(); // run the checkCourse function
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break; // jump out of this loop
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}
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if (curDist < TURN_DIST) { // if current distance is less than the turn distance
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changeRoute(); // run the changeRoute function
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}
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if (curDist > curDist) {
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maxAngle = pos;
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}
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if (pos > 90 && curDist > curLeft) {
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curLeft = curDist;
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}
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if (pos == 90 && curDist > curFront) {
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curFront = curDist;
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}
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if (pos < 90 && curDist > curRight) {
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curRight = curDist;
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}
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}
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maxLeft = curLeft;
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maxRight = curRight;
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maxFront = curFront;
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void setCourse() { // set direction for travel based on a very basic distance map, simply which direction has the greatest distance to and object - turning right or left?
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if (maxAngle < 90) {
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turnRight();
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}
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if (maxAngle > 90) {
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turnLeft();
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}
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maxLeft = 0;
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maxRight = 0;
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maxFront = 0;
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void checkCourse() { // we're about to hit something so move backwards, stop, find where the empty Route is.
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moveBackward();
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delay(500);
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moveStop();
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setCourse();
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void changeRoute() {
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if (pos < 90) {
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lookLeft(); // when current position of sensor is less than 90-degrees, it means the object is on the right hand side so look left
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}
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if (pos > 90) {
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lookRight(); // when current position of sensor is greater than 90-degrees, it means the object is on the left hand side so look right
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}
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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int readPing() { // read the ultrasonic sensor distance
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// delay(70);
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// unsigned int uS = sonar.ping();
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// int cm = uS / US_ROUNDTRIP_CM;
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// return cm
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return distance();
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void checkForward() {
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if (motorSet == "FORWARD") {
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leftMotor.run(FORWARD); // ensure motors are going forward
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rightMotor.run(FORWARD);
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}
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void checkBackward() {
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if (motorSet == "BACKWARD") {
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leftMotor.run(BACKWARD); // ensure motors are going backward
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rightMotor.run(BACKWARD);
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}
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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// In some cases, the Motor Drive Shield may just stop if the supply voltage is too low (due to using only four NiMH AA cells).
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// The above functions simply remind the Shield that if it's supposed to go forward, then ensure it is going forward and vice versa.
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//-------------------------------------------------------------------------------------------------------------------------------------
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void moveStop() {
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leftMotor.run(RELEASE); // stop the motors.
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rightMotor.run(RELEASE);
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void moveForward() {
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motorSet = "FORWARD";
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leftMotor.run(FORWARD); // turn it on going forward
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rightMotor.run(FORWARD); // turn it on going forward
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for (speedSet = 0; speedSet < MAX_SPEED; speedSet += 2) // slowly bring the speed up to avoid loading down the batteries too quickly
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{
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leftMotor.setSpeed(speedSet + MOTORS_CALIBRATION_OFFSET);
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rightMotor.setSpeed(speedSet);
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delay(5);
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}
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void moveBackward() {
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motorSet = "BACKWARD";
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leftMotor.run(BACKWARD); // turn it on going forward
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rightMotor.run(BACKWARD); // turn it on going forward
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for (speedSet = 0; speedSet < MAX_SPEED; speedSet += 2) // slowly bring the speed up to avoid loading down the batteries too quickly
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{
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leftMotor.setSpeed(speedSet + MOTORS_CALIBRATION_OFFSET);
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rightMotor.setSpeed(speedSet);
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delay(5);
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}
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void turnRight() {
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motorSet = "RIGHT";
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leftMotor.run(FORWARD); // turn motor 1 forward
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rightMotor.run(BACKWARD); // turn motor 2 backward
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delay(400); // run motors this way for 400ms
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motorSet = "FORWARD";
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leftMotor.run(FORWARD); // set both motors back to forward
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rightMotor.run(FORWARD);
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void turnLeft() {
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motorSet = "LEFT";
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leftMotor.run(BACKWARD); // turn motor 1 backward
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rightMotor.run(FORWARD); // turn motor 2 forward
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delay(400); // run motors this way for 400ms
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motorSet = "FORWARD";
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leftMotor.run(FORWARD); // turn it on going forward
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rightMotor.run(FORWARD); // turn it on going forward
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void lookRight() {
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rightMotor.run(BACKWARD); // looking right? set right motor backwards for 400ms
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delay(400);
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rightMotor.run(FORWARD);
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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void lookLeft() {
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leftMotor.run(BACKWARD); // looking left? set left motor backwards for 400ms
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delay(400);
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leftMotor.run(FORWARD);
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}
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int distance() {
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// The sensor is triggered by a HIGH pulse of 10 or more microseconds.
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// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
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digitalWrite(trigPin, LOW);
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delayMicroseconds(5);
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digitalWrite(trigPin, HIGH);
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delayMicroseconds(10);
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digitalWrite(trigPin, LOW);
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// Read the signal from the sensor: a HIGH pulse whose
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// duration is the time (in microseconds) from the sending
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// of the ping to the reception of its echo off of an object.
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pinMode(echoPin, INPUT);
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duration = pulseIn(echoPin, HIGH);
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// Convert the time into a distance
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cm = (duration/2) / 29.1; // Divide by 29.1 or multiply by 0.0343
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inches = (duration/2) / 74; // Divide by 74 or multiply by 0.0135
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Serial.print(inches);
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Serial.print("in, ");
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Serial.print(cm);
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Serial.print("cm");
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Serial.println();
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return cm;
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}
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//-------------------------------------------------------------------------------------------------------------------------------------
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