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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;
}
}
@tbair8

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tbair8 commented Feb 4, 2019

Awesome!! Thanks for sharing.

@redalrt

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redalrt commented Jul 30, 2019

Very cool, Thank you!

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