challenge-bot.com Git - challenge-bot/blob - arduino-sketches/pushbutton/pushbutton.ino

   1 /*
   2     This program is free software: you can redistribute it and/or modify
   3     it under the terms of the GNU Affero General Public License as
   4     published by the Free Software Foundation, either version 3 of
   5     the License, or (at your option) any later version.
   6
   7     This program is distributed in the hope that it will be useful,
   8     but WITHOUT ANY WARRANTY; without even the implied warranty of
   9     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10     GNU Affero General Public License for more details.
  11
  12     You should have received a copy of the GNU Affero General Public License
  13     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  14  */
  15
  16 // pin 13 controls the arduino's built-in LED
  17 int led_pin = 13;
  18 // connect the button to pin 2
  19 int button_pin = 2;
  20 // initially, the button is not pressed.
  21 //  0 means not pressed, 1 means pressed
  22 int button_value = 0;
  23
  24 void setup(){
  25   Serial.begin(9600);}
  26
  27 void loop(){
  28   // see if you can figure out how this logic works
  29   if(digitalRead(button_pin) != button_value){
  30     Serial.println("button state changed!");}
  31   // read the value of the button pin during this loop,
  32   //  and save it in a box named "button_value"
  33   button_value = digitalRead(button_pin);
  34   // write the value to the led pin
  35   digitalWrite(led_pin, button_value);}