DebounceIN library allows debouncing a GPIO pin interrupt

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Comitter:
nleoni
Date:
Tue Feb 18 16:52:49 2014 +0000
Commit message:
1st commit

Changed in this revision

DebounceInt.cpp Show annotated file Show diff for this revision Revisions of this file
DebounceInt.h Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebounceInt.cpp	Tue Feb 18 16:52:49 2014 +0000
@@ -0,0 +1,73 @@
+/* DebounceInt Library */
+/* This class enables debouncing a GPIO interrupt from a specific MBED pin            */
+/* It does so by using the InterruptMask library to temporarily mask the interrupt    */
+/* from the specified pin for a user specified delay specified in us. After the delay */
+/* time has passed the interrupt is unmasked (reenabled) and any pending interrupts   */
+/* also cleared. The library gives you the flexibiity to debounce on either the       */
+/* rising or falling edge interrupts.                                                 */
+// Usage:
+// Declare a DebounceInt object with a valid mbed pin (p5-p30 except p19 and p20) as 
+// an argument. Within your interrupt service routine call the appropriate debounce
+// method debouncePinRise or debouncePinFall. 
+// Requires the InterruptMask library available at: https://mbed.org/users/nleoni/code/InterruptMask/
+
+#include "DebounceInt.h"
+
+//Default constructor, required but not to be used, will yield error and exit.
+    DebounceInt::DebounceInt(){
+        exit(1);
+    }
+    
+//Constructor with PinName, delay will remain default value
+    DebounceInt::DebounceInt(PinName pin){
+    // Inputs:
+    // PinName pin: Expected Proper Mbed Pin (e.g. p12), program will exit otherwise
+        this->pinIntMask = new InterruptMask(pin);
+        this->setDelay(_DEBOUNCEINTDELAYDEFAULT);    
+    }
+
+//Constructor with PinName and specified delay in micro-seconds
+    DebounceInt::DebounceInt(PinName pin,unsigned int delay_us){
+    // Inputs:
+    // PinName pin: Expected Proper Mbed Pin (e.g. p12), program will exit otherwise
+    // unsigned int delay: Expected positive delay, will force delay to be larger
+    // than minimum delay _MINDBOUNCEDELAY
+        this->pinIntMask = new InterruptMask(pin);        
+        this->setDelay(delay_us);
+    }
+
+//method to modify delay for debounce in us
+    void DebounceInt::setDelay(unsigned int delay_us){
+    // Inputs:
+    // unsigned int delay: Expected positive delay, will force delay to be larger
+    // than minimum delay _MINDBOUNCEDELAY
+        if(delay_us>(_MINDBOUNCEDELAY) ){
+            this->delay=delay_us;
+        } else { 
+            this->delay=_MINDBOUNCEDELAY;
+        }
+    } 
+
+//method to be called within Interrupt Service Routine to debounce GPIO pin on rising edge
+    void DebounceInt::debouncePinRise(void){
+        this->pinIntMask->maskIntR();
+        this->debounceCallBack.attach_us(this,&DebounceInt::debounceCallbackPinRise,this->delay);
+    }
+    
+//internal callback used to re-enable (unmask) interrupts on rising edge
+    void DebounceInt::debounceCallbackPinRise(void){
+        this->pinIntMask->ClrInt();
+        this->pinIntMask->unMaskIntR();
+    }
+
+//method to be called within Interrupt Service Routine to debounce GPIO pin on falling edge
+    void DebounceInt::debouncePinFall(void){
+        this->pinIntMask->maskIntF();
+        this->debounceCallBack.attach_us(this,&DebounceInt::debounceCallbackPinFall,this->delay);
+    }
+    
+//internal callback used to re-enable (unmask) interrupts on falling edge
+    void DebounceInt::debounceCallbackPinFall(void){
+        this->pinIntMask->ClrInt();
+        this->pinIntMask->unMaskIntF();
+    }
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebounceInt.h	Tue Feb 18 16:52:49 2014 +0000
@@ -0,0 +1,66 @@
+/* DebounceInt Library */
+/* This class enables debouncing a GPIO interrupt from a specific MBED pin            */
+/* It does so by using the InterruptMask library to temporarily mask the interrupt    */
+/* from the specified pin for a user specified delay specified in us. After the delay */
+/* time has passed the interrupt is unmasked (reenabled) and any pending interrupts   */
+/* also cleared. The library gives you the flexibiity to debounce on either the       */
+/* rising or falling edge interrupts.                                                 */
+// Usage:
+// Declare a DebounceInt object with a valid mbed pin (p5-p30 except p19 and p20) as 
+// an argument. Within your interrupt service routine call the appropriate debounce
+// method debouncePinRise or debouncePinFall. 
+// Requires the InterruptMask library available at: https://mbed.org/users/nleoni/code/InterruptMask/
+
+//
+// Example Code: toggles LED1 on falling edge interrupt
+//#include "mbed.h"
+//#include "DebounceInt.h"
+//DigitalOut myled(LED1);
+//InterruptIn upPressed(p15);
+//DebounceInt *upPressedDebounce; //debounce object to be used within interrupt for joystick up
+//                                //note that pointer is defined here to have global variable
+//                                //but constructor call must be within the main function.
+//int main() {
+//  upPressedDebounce = new DebounceInt(p15,50000); //create DebounceInt object for p15 interrupt
+//                                                  //with a 50000 us delay (interrupt disabled to avoid bounce)                                    
+//  upPressed.fall(ISRup);            //attach joystick up click on falling edge, that is when
+//                                    //user releases the joystick the action will happen
+//  while(1){
+//  }
+//}
+//void ISRup(void){
+//    upPressedDebounce->debouncePinFall(); //call debounce method on pin fall, will disable interrupt for 
+//                                          //specified delay
+//    myled=!myled;
+//}
+
+
+#include "mbed.h"
+#include "InterruptMask.h"
+
+#ifndef DEBOUNCEINT
+#define DEBOUNCEINT
+#define _DEBOUNCEINTDELAYDEFAULT 50000 //useconds, this number would be about 50 ms
+#define _MINDBOUNCEDELAY 5
+class DebounceInt{
+public://members
+private://members
+    InterruptMask* pinIntMask; //Internal InterruptMask object
+    unsigned int delay; //this is the debounce delay, during which the interrupt in question is masked
+    Timeout debounceCallBack;
+
+public://methods
+    DebounceInt();     //Default constructor, required but not to be used, will yield error and exit.
+    DebounceInt(PinName pin);//Constructor with PinName, delay will remain default value
+    DebounceInt(PinName pin,unsigned int delay_us);//Constructor with PinName and specified delay in micro-seconds
+    void setDelay(unsigned int); //method to modify delay for debounce in us
+    void debouncePinRise(void);  //method to be called within Interrupt Service Routine to debounce GPIO pin on rising edge
+    void debouncePinFall(void);  //method to be called within Interrupt Service Routine to debounce GPIO pin on falling edge
+    
+private://methods
+    void debounceCallbackPinRise(void); //internal callback used to re-enable (unmask) interrupts on rising edge
+    void debounceCallbackPinFall(void); //internal callback used to re-enable (unmask) interrupts on falling edge
+    
+};
+
+#endif