Good Evening All,
I am currently trying to do the ImechE design challenge at Uni and need some guidance on my code and project. Unfortunately I have very little coding experience.
Below is a rough schematic of the ciricuit:
Essentially, the circuit contains the following components:
DC motor
L298N motor driver board
1 x limit switch
1 x arduino board.
this is my plan for the project:
step 1) switch on arduino, motor rotates clockwise.
step 2) Once the limit switch is present the motor polarity is changed.
step 3) when the distance that the ultrasonic sensor measures is greater than 2m it ignores the limit switch and changes the polarity again.
step 4) when the distance is 1m it stops the motor.
The overall specification can be found at the following URL:
(please click on the 2023 2nd year document).
However, I have some questions:
- is the use of a component correct for what I am trying to do?
- Would the code shown below work:
// Constants and variables are set for the Arduino pins and the corresponding functions
int trigPin = 6; // TrigPin to D6
int echoPin = 5; // EchoPin to D5
int in1 = 10; // Left Side MOSFET Motor Controller to D10
int in2 = 9; //Left Side MOSFET Motor Controller to D9
int SW = 13; // Microswitch connect to D13
float d; // Declaration of the distance variable used within the loop() function
int S; // Declaration of the switch variable used within the loop() function, in the form of binary values
int Phase = 0; // Variable that counts phases
void setup() //Function to be executed once.
{
pinMode(in1, OUTPUT); // Sets pin in1 in OUTPUT mode
pinMode(in2, OUTPUT); // Sets pin in2 in OUTPUT mode
pinMode(trigPin, OUTPUT);// Sets the pin trigPin in OUTPUT mode
pinMode(echoPin, INPUT); // Sets the pin echoPin in INPUT mode
pinMode (SW, INPUT_PULLUP); // Sets the pin SW in INPUT_PULLUP mode
Serial.begin(9600);// Starts the serial communication
}
void loop() { //Specified function loops indefinitely until Arduino is turned off
switch(Phase){ //Switches between the multiple cases in the phases of the order coded
case 0: // Case 0 ensures that when the switch has not been activated, the motor turns clockwise and travels up the pipe.
rotateCW();
d = distanceRead(); //Distance measured by the ultrasonic sensor
S = digitalRead (SW); //Switch input read
if (S==0) //Switch is OFF - '0' and ON - '1'. The motor rotates ant-clockwise when the switch is pressed
{
Phase = 1;
}
Serial.print(Phase);
break; //End of phase.
//Set distance here for when the model has gone up and back to the bottom to reverse polarity again
case 1: // Case 1: Anticlockwise rotation of the motor if the distance read is greater than or equal to 236cm
rotateACW();
d=distanceRead();
if(d >=236)
{
Phase = 2;
Serial.print(Phase);
}
break;
//Set distance here for distance from datum to red line
case 2: // Case 2: Clockwise rotation of the motor
//if the distance read is less than or equal to 106cm, stop the motor
rotateCW();
d=distanceRead();
if(d<=106)
{
stopMotor();
Phase = 3;
Serial.print(Phase);
}
break;
default:
Serial.println("Trial Completed"); // Print the message once the while loop has terminated
while(1); //Stops the loop()
}
}
//***************** Function declaration ********************
//Function names and values are declared
int rotateCW(){
digitalWrite(in1, LOW);
digitalWrite(in2, HIGH);
}
int rotateACW(){
digitalWrite(in1, HIGH);
digitalWrite(in2, LOW);
}
int stopMotor(){
digitalWrite(in1, LOW);
digitalWrite(in2, LOW);
}
int distanceRead(){
float c; //Declaration of the speed of sound in air variable
float duration; //Declaration of the duration of the ultrasonic wave variable
float distance; //Declaration of the distance variable within the function declaration
float T = 20.5; // Room temperature is in celsius
digitalWrite(trigPin, LOW);// Clears the trigPin
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);// Sets the trigPin on HIGH state for 10 micro seconds
delayMicroseconds(10);
digitalWrite(trigPin, LOW); // Sets the trigPin on LOW state
c = (331.4 +0.6*T)/10000; // Reference: http://hyperphysics.phyastr.gsu.edu/hbase/Sound/souspe.html
duration = pulseIn(echoPin, HIGH);// Reads the echoPin, returns the sound wave travel time in microseconds
distance = duration*c; //Displayed distance as a result of time passed and set value of speed of sound wave travel
return distance;
}
Any help will be greatly appreciated.