Timing issues with running a motor from a button press

Projects Programming
8

Hey Stefan, thank you for your detailed answer. Sorry for my slow reply. I've been swamped so haven't had time to respond until now. I understand the need to have a resistor between the input pin and the I previously had a resistor on my breadboard which is why I was using "pinMode(buttonPin, INPUT)". After understanding this post more and reading up on INPUT_PULLUP I simplified my wiring and I'm now using the internal pullup resistor.

This is the code I'm now attempting to use:

int motorPin = 9;   //Define motor input pin
int buttonPin = 2;  //Define button input pin

void setup() {
  pinMode(motorPin, OUTPUT);         //Set motorPin as an Output
  pinMode(buttonPin, INPUT_PULLUP);  //Set buttonPin as an Input
}

void loop() {
  if (digitalRead(buttonPin) == LOW) {  //When button is pressed
    digitalWrite(motorPin, HIGH);
    delay(3000);                  //run motor for 30000ms (3s)
    digitalWrite(motorPin, LOW);  //otherwise turn motor off
  }
}

When I press my button it runs the motor, but the motor doesn't stop spinning after 3000ms.

I tried to use the serial monitor to understand what's happening, and it printed "1" then after another 3 seconds printed "1" again, so I suspect the button is somehow continuously being triggered. Admittedly, I don't fully understand how to implement the serial monitor so that information could be misleading.

Should I be using some other syntax instead of "digitalWrite(motorPin, LOW);" after my delay?

Here is the code I used when trying to use the serial monitor:

int motorPin = 9;   //Define motor input pin
int buttonPin = 2;  //Define button input pin

void setup() {
  pinMode(motorPin, OUTPUT);         //Set motorPin as an Output
  pinMode(buttonPin, INPUT_PULLUP);  //Set buttonPin as an Input
  Serial.begin(9600);                //Start serial monitor
}

void loop() {
  if (digitalRead(buttonPin) == LOW) {  //When button is pressed
    digitalWrite(motorPin, HIGH);
    Serial.println(digitalRead (motorPin), DEC);
    delay(3000);                  //run motor for 30000ms (3s)
    digitalWrite(motorPin, LOW);  //otherwise turn motor off
  }
}

Thanks for the help!