Newbie - LED timer w/ up down time buttons

Other Hardware LEDs and Multiplexing
1

I just started working with my arduino and built some simple programs led projects, but what I want to do next is more complex and I don't know where to start.

What I want to do next is build a LED timer. When you push the button the LED light remains on for a determined amout of time (say 10 seconds) and then shuts off and stays off. The determined amount of time then can be changed thru a push button switch up/down in seconds etc..

Here is where I am at now with a basic momentary LED on when button is pushed.

int ledPin = 12;                // LED is connected to pin 12
int switchPin = 2;              // switch is connected to pin 2
int val;                        // variable for reading the pin status


void setup() {
  pinMode(ledPin, OUTPUT);      // Set the LED pin as output
  pinMode(switchPin, INPUT);    // Set the switch pin as input
}


void loop(){
  val = digitalRead(switchPin);   // read input value and store it in val
  if (val == LOW) {               // check if the button is pressed
    digitalWrite(ledPin, HIGH);   // turn LED on
  }
  if (val == HIGH) {              // check if the button is not pressed
    digitalWrite(ledPin, LOW);    // turn LED off
  }
}
2

Or a potentiometer to adjust time.

3

try this:

void loop(){
// add this
int delayTime = (analogRead (A0)*10);  // delay up to 10.24 seconds 
  val = digitalRead(switchPin);   // read input value and store it in val
  if (val == LOW) {               // check if the button is pressed
    digitalWrite(ledPin, HIGH);   // turn LED on
delay (delayTime);  // keep the LED on
  }
4

Thanks :slight_smile:

I updated my code and added print function to show resistance in pot.. I was trying to use millis but I did not know how to implement the millis code. I will test it tonight

int ledPin = 12;                // LED is connected to pin 12
int switchPin = 2;              // switch is connected to pin 2
int val;                        // variable for reading the pin status
int analogPin = 0;               // variable pots impute to control time via resistance


void setup() {
  Serial.begin(9600);            //begin serial communications lcd display
  pinMode(ledPin, OUTPUT);      // Set the LED pin as output
  pinMode(switchPin, INPUT);    // Set the switch pin as input
}


void loop(){

  int sensorValue = analogRead(A0);      // store resistance value
  Serial.println(sensorValue, DEC);
  int delayTime = (analogRead (A0)*10);  // delay up to 10.24 seconds 
  val = digitalRead(switchPin);   // read input value and store it in val
  if (val == LOW) {               // check if the button is pressed
    digitalWrite(ledPin, HIGH);   // turn LED on
    delay (delayTime);  // keep the LED on


  }
  if (val == HIGH) {              // check if the button is not pressed
    digitalWrite(ledPin, LOW);    // turn LED off
  }
}