Task 31A -- Standard Digital Input and Output - No Interrupts

This is the circuit diagram for both parts of the Interrupts task.

It's fairly simple. It comes from the Interrupts site of the Code Project, the author being Dave Auld, who also wrote both code sections, & provides a really good introduction to interrupts.
Arduino's Reference to attachInterrupts is less comprehensive but gives all the necessary info.


I had to use a 150Ohm resistor in place of a push-switch (which i couldn't find for some reason - i DO have one.. somewhere..).  It worked nicely thank-you!
I connected one end of the resistor to Digital Pin 2 on my little breadboard, & touched the other end to GND - in this case the grounded lead of the LED, which promptly turned OFF  :-)  & back ON again when i released the 150Ohm resistor from contact..
..as expected!

/*
 * Project:    Interrupts_part_A_621task31
 * Author:     DaveAuld, tidied (not much! :-) ) by Jane-Maree Howard
 * Date:       23 Feb 2010
 * Platform:   Arduino 22
 * Purpose:    To demonstrate a simple non-interrupt LED-switch
 * Operation:  Description:
 *             "Set up the Arduino as per the schematic
 *              and upload the code below to the microprocessor.
 *              Here you read the value of an input,
 *              do a conditional comparison, run some lengthy routine and repeat.
 *              This will give unpredictable outputs on the LED
 *              due to the lengthy process being at an undetermined point
 *              in relation to when the input button is triggered.
 *              Sometimes the LED will change state immediately,
 *              other times nothing happens, and then
 *              sometimes you need to hold the button for a while
 *              for the state changed to be recognised.
 *              [This is code PART A in the downloaded source file.]"
 *             I had to use a 150Ohm resistor because i couldn't find my push-switch!
 *             It worked fine! 
 */


int pbIn = 2;          // Digital input on pin 2
int ledOut = 4;        // The output LED pin
int state = LOW;       // The input state

void setup()
{
  // Set up the digital Pin 2 to an Input and Pin 4 to an Output
  pinMode(pbIn, INPUT);
  pinMode(ledOut, OUTPUT);
}//setup()

void loop()
{
  state = digitalRead(pbIn);      //Read the button

  digitalWrite(ledOut, state);    //write the LED state

  //Simulate a long running process or complex task
  for (int i = 0; i < 100; i++)
  {
     // do nothing but waste some time
     delay(10);
  }//for()
}//loop()
//END
.