NormalUniverse · March 14, 2018 09:28 · Mar 14, 2018
diff --git a/Simple Button Debounce State Machine b/Simple Button Debounce State Machine
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+//Title: Button Debouncing using a State Machine, Complex Version
+//Author: Chris Guichet
+//Date: Jan 15, 2018
+//
+//Description:
+//  -A State Machine is a useful tool to organize complex code
+//  -Think of it like the next step beyone "If Else" statements
+//  -This example code uses a State Machine to handle tac switch debouncing
+//  -It also has a "Hold" function to enable interaction with long button presses
+//
+//Wiring Instructions:
+//  -Wire a SPST momentary switch between a Digital I/O pin and Ground.  (I use pin 12)
+//    (we will use an internal pullup resistor, so no need to worry about wiring a resistor)
+//
+//Code Reading Tip:
+//  -Before mentally digesting this code, collapse all folds to get a bird's eye view.
+//  -Ctrl-a (to select all) -> Right Click -> Folding -> Collapse All Folds
+
+//Top Level Variables:
+int DEBUG = 1;  //Set to 1 to enable serial monitor debugging info
+
+//Switch Variables:
+int state_s1 = 0;
+int state_prev_s1 = 0;
+int pin_s1 = 12;
+int val_s1 = 0;
+unsigned long t_s1 = 0;
+unsigned long t_0_s1 = 0;
+unsigned long bounce_delay_s1 = 10;
+unsigned long hold_delay_s1 = 1000;
+
+void setup() {
+  // initialize digital pins
+  pinMode(12,INPUT_PULLUP); //INPUT_PULLUP will use the Arduino's internal pullup resistor
+
+  //if DEBUG is turned on, intiialize serial connection
+  if(DEBUG) {Serial.begin(115200);Serial.println("Debugging is ON");}
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  SM_s1();
+
+  //If debug is enabled, do some printing of messages
+
+  //Let the world know when the state changes
+  if(DEBUG) {
+    if(state_prev_s1 != state_s1) {Serial.print("Switch State: "); Serial.println(state_s1);}
+    };
+
+  //Let the world know when the button is held or pressed  
+  if (DEBUG) {Serial.println("HOLDED!!");}
+  if (DEBUG) {Serial.println("TRIGGERED!!");}
+}
+
+void SM_s1() {
+  //Almost every state needs these lines, so I'll put it outside the State Machine
+  val_s1 = digitalRead(pin_s1);
+  state_prev_s1 = state_s1;
+
+  //State Machine Section
+  switch (state_s1) {
+    case 0: //RESET!
+      //Catch all "home base" for the State MAchine
+      state_s1 = 1;
+    break;
+
+    case 1: //WAIT
+      //Wait for the switch to go low
+      if (val_s1 == LOW) {state_s1 = 2;}
+    break;
+
+    case 2: //ARMING!
+      //Record the time and proceed to ARMED
+      t_0_s1 = millis();
+      state_s1 = 3;
+    break;
+
+    case 3: //ARMED
+      //Check to see if the proper has delay has passed.  If a bounce occures then RESET
+      t_s1 = millis();
+      if (t_s1 - t_0_s1 > bounce_delay_s1) {state_s1 = 4;}
+      if (val_s1 == HIGH) {state_s1 = 0;}
+    break;
+
+    case 4: //DRAWN
+      //If switch goes HIGH, then TRIGGER. Also check timer for a "Long Pess"
+      t_s1 = millis();
+      if (val_s1 == HIGH) {state_s1 = 5;}
+      if (t_s1 - t_0_s1 > hold_delay_s1) {state_s1 = 6;}
+    break;
+
+    case 5: //TRIGGERED!
+      //reset the State Machine
+      state_s1 = 0;
+    break;
+
+    case 6: //HOLD!
+      //proceed to LOW WAIT
+      state_s1 = 7;
+    break;
+
+    case 7: //LOW WAIT
+      //wait for switch to go back HIGH, then reset
+      if (val_s1 == HIGH) {state_s1 = 0;}
+    break;
+  }
+
+}