V3.3.1 - Avoid mistakenly double press detection after boot.

Author: ArminJo

README.md

@@ -17,11 +17,11 @@ Available as [Arduino library "EasyButtonAtInt01"](https://www.arduinolibraries.
 Debouncing is merely done by ignoring a button change within the debouncing time (default 50 ms).
 So **button state is instantly available** without debouncing delay!
 - Implements **toggle button** functionality.
-- Support for **double press detection** is included. See [EasyButtonExample](examples/EasyButtonExample/EasyButtonExample.ino#L112) and [Callback example](examples/Callback/Callback.ino#L78).
-- Support for **long press detection**, is included. See [Callback example](examples/Callback/Callback.ino#L98).
+- Support for **double press detection** is included. See [EasyButtonExample](examples/EasyButtonExample/EasyButtonExample.ino#L111) and [Callback example](examples/Callback/Callback.ino#L77).
+- Support for **long press detection**, is included. See [Callback example](examples/Callback/Callback.ino#L97).
 - Support for **active high buttons**.
 - Small memory footprint.
-- Support to **measure maximum bouncing period of a button**. See [DebounceTest example](examples/DebounceTest/DebounceTest.ino#L64).
+- Support to **measure maximum bouncing period of a button**. See [DebounceTest example](examples/DebounceTest/DebounceTest.ino#L62).
 
 ## Table of available pins for the 2 buttons
 | CPU | Button 0 | Button 1 using INT1 | Button 1 using PCINT, if INT1_PIN is defined !=3 |
@@ -154,7 +154,7 @@ Modify them by enabling / disabling them, or change the values if applicable.
 | `USE_BUTTON_1` | disabled | Enables code for button at INT1 (pin3 on 328P, PA3 on ATtiny167, PCINT0 / PCx for ATtinyX5). |
 | `BUTTON_IS_ACTIVE_HIGH` | disabled | Enable this if you buttons are active high. |
 | `USE_ATTACH_INTERRUPT` | disabled | This forces use of the arduino function attachInterrupt(). It is required if you get the error "multiple definition of \`__vector_1'" (or \`__vector_2'), because another library uses the attachInterrupt() function. |
-| `NO_BUTTON_RELEASE_CALLBACK` | disabled | Disables the code for release callback. This saves 2 bytes RAM and 64 bytes FLASH. |
+| `NO_BUTTON_RELEASE_CALLBACK` | disabled | Disables the code for release callback. This saves 2 bytes RAM and 64 bytes program space. |
 | `BUTTON_DEBOUNCING_MILLIS` | 50 | With this you can adapt to the characteristic of your button. |
 | `ANALYZE_MAX_BOUNCING_PERIOD` | disabled | Analyze the buttons actual debounce value. |
 | `BUTTON_LED_FEEDBACK` | disabled | This activates LED_BUILTIN as long as button is pressed. |
@@ -197,6 +197,9 @@ bool checkForForButtonNotPressedTime(uint16_t aTimeoutMillis);
 ```
 
 # Revision History
+###  Version 3.3.1
+- Avoid mistakenly double press detection after boot.
+
 ###  Version 3.3.0
 - Renamed EasyButtonAtInt01.cpp.h to EasyButtonAtInt01.hpp.
 

examples/Callback/Callback.ino

@@ -76,8 +76,6 @@ void blinkLEDBlocking(uint8_t aLedPin, uint8_t aBlinkCount, uint16_t aDelay) {
 void handleButtonPress(bool aButtonToggleState) {
     /*
      * Double press (< 200 ms) detection by calling checkForForDoublePress() once at button press time.
-     * Be aware, that the first press after booting may be detected as double press!
-     * This is because the "last time of press" is initialized with 0 milliseconds, which is interpreted as the first press happened at the beginning of boot.
      */
     if (Button0AtPin2.checkForDoublePress(300)) {
         Serial.print(F("Double press "));

examples/EasyButtonExample/ATtinySerialOut.hpp

@@ -243,7 +243,7 @@ void writeUnsignedByte(uint8_t aByte) {
 }
 
 /*
- * 2 Byte Hex output
+ * 2 byte Hex output
  */
 void writeUnsignedByteHex(uint8_t aByte) {
     char tStringBuffer[3];
@@ -261,7 +261,7 @@ void writeUnsignedByteHex(uint8_t aByte) {
 }
 
 /*
- * 2 Byte Hex output with 2 Byte prefix "0x"
+ * 2 byte Hex output with 2 byte prefix "0x"
  */
 void writeUnsignedByteHexWithPrefix(uint8_t aByte) {
     writeBinary('0');
@@ -354,7 +354,7 @@ void TinySerialOut::flush() {
 }
 
 /*
- * 2 Byte Hex output with 2 Byte prefix "0x"
+ * 2 byte Hex output with 2 byte prefix "0x"
  */
 void TinySerialOut::printHex(uint8_t aByte) {
     writeUnsignedByteHexWithPrefix(aByte);
@@ -530,7 +530,7 @@ inline void delay4CyclesExact(uint16_t a4Microseconds) {
  * 115200 baud - 8,680 cycles per bit, 86,8 per byte at 1 MHz
  *
  *  Assembler code for 115200 baud extracted from Digispark core files:
- *  Code size is 196 Byte (including first call)
+ *  Code size is 196 byte (including first call)
  *
  *   TinySerialOut.h - Tiny write-only software serial.
  *   Copyright 2010 Rowdy Dog Software. This code is part of Arduino-Tiny.
@@ -680,7 +680,7 @@ void write1Start8Data1StopNoParity(uint8_t aValue) {
 }
 #else
 /*
- * Small code using loop. Code size is 76 Byte (including first call)
+ * Small code using loop. Code size is 76 byte (including first call)
  *
  * 1 MHz CPU Clock
  *  26,04 cycles per bit, 260,4 per byte for 38400 baud at 1 MHz Clock

examples/EasyButtonExample/EasyButtonExample.ino

@@ -109,9 +109,7 @@ void loop() {
 
 void handleButtonPress(bool aButtonToggleState) {
     /*
-     * This function works reliable only if called early in press callback function
-     * Be aware, that the first press after booting may be detected as double press!
-     * This is because the "last time of press" is initialized with 0 milliseconds, which is interpreted as the first press happened at the beginning of boot.
+     * checkForDoublePress() works reliable only if called early in press callback function
      */
     if (Button0AtPin2.checkForDoublePress()) {
         Serial.println(F("Button 0 double press (< 400 ms) detected"));

library.json

@@ -6,7 +6,7 @@
     "type": "git",
     "url": "https://github.com/ArminJo/EasyButtonAtInt01"
   },
-  "version": "3.3.0",
+  "version": "3.3.1",
   "exclude": "pictures",
   "authors": {
     "name": "Armin Joachimsmeyer",

library.properties

@@ -1,9 +1,9 @@
 name=EasyButtonAtInt01
-version=3.3.0
+version=3.3.1
 author=Armin Joachimsmeyer
 maintainer=Armin Joachimsmeyer <armin.arduino@gmail.com>
 sentence=Small and easy to use Arduino library for using push buttons at INT0/pin2 and / or any PinChangeInterrupt pin.<br/>Functions for long and double press detection are included.<br/><br/>Just connect buttons between ground and any pin of your Arduino - that's it<br/><br/><b>No call</b> of begin() or polling function like update() required. No blocking debouncing delay.<br/>
-paragraph=<br/>Define an EasyButtonIn in you main program and use <i>ButtonStateIsActive</i> or <i>ButtonToggleState</i> to determine your action.<br/>Or use a <b>callback function</b> which will be called once on every button press or release.<br/><br/>Usage:<pre>#define USE_BUTTON_0<br/>#include "EasyButtonAtInt01.hpp"<br/>EasyButton Button0AtPin2;<br/><br/>void setup() {}<br/>void loop() {<br/>...<br/>    digitalWrite(LED_BUILTIN, Button0AtPin2.ButtonToggleState);<br/>...<br/>}</pre><br/><br/><b>New: </b>Renamed EasyButtonAtInt01.cpp.h to EasyButtonAtInt01.hpp. => <b>You must change: #include "EasyButtonAtInt01.cpp.h" to: #include "EasyButtonAtInt01.hpp"</b><br/>
+paragraph=<br/>Define an EasyButtonIn in you main program and use <i>ButtonStateIsActive</i> or <i>ButtonToggleState</i> to determine your action.<br/>Or use a <b>callback function</b> which will be called once on every button press or release.<br/><br/>Usage:<pre>#define USE_BUTTON_0<br/>#include "EasyButtonAtInt01.hpp"<br/>EasyButton Button0AtPin2;<br/><br/>void setup() {}<br/>void loop() {<br/>...<br/>    digitalWrite(LED_BUILTIN, Button0AtPin2.ButtonToggleState);<br/>...<br/>}</pre><br/><br/><b>New: </b>Avoid mistakenly double press detection after boot.</b><br/>
 category=Signal Input/Output
 url=https://github.com/ArminJo/EasyButtonAtInt01
 architectures=avr

src/EasyButtonAtInt01.h

@@ -12,7 +12,7 @@
  *  #include "EasyButtonAtInt01.h"
  *  EasyButton Button0AtPin2(true);
  *
- *  Copyright (C) 2018  Armin Joachimsmeyer
+ *  Copyright (C) 2018-2022  Armin Joachimsmeyer
  *  armin.joachimsmeyer@gmail.com
  *
  *  This file is part of EasyButtonAtInt01 https://github.com/ArminJo/EasyButtonAtInt01.
@@ -34,7 +34,7 @@
 #ifndef EASY_BUTTON_AT_INT01_H_
 #define EASY_BUTTON_AT_INT01_H_
 
-#define VERSION_EASY_BUTTON "3.2.0"
+#define VERSION_EASY_BUTTON "3.2.1"
 #define VERSION_EASY_BUTTON_MAJOR 3
 #define VERSION_EASY_BUTTON_MINOR 2
 // The change log is at the bottom of the file
@@ -62,7 +62,7 @@
 /*
  * Define USE_ATTACH_INTERRUPT to force use of the arduino function attachInterrupt().
  * It is required if you get the error " multiple definition of `__vector_1'" (or `__vector_2'), because another library uses the attachInterrupt() function.
- * For one button it needs additional 160 bytes FLASH, for 2 buttons it needs additional 88 bytes.
+ * For one button it needs additional 160 bytes program space, for 2 buttons it needs additional 88 bytes.
  */
 //#define USE_ATTACH_INTERRUPT
 //
@@ -84,7 +84,7 @@
 #endif
 
 /*
- * Activate this to save 2 bytes RAM and 64 bytes FLASH
+ * Activate this to save 2 bytes RAM and 64 bytes program space
  */
 //#define NO_BUTTON_RELEASE_CALLBACK
 //
@@ -128,7 +128,7 @@
 #endif
 
 /*
- * These defines are here to enable saving of 150 bytes FLASH if only one button is needed
+ * These defines are here to enable saving of 150 bytes program space if only one button is needed
  */
 //#define USE_BUTTON_0
 //#define USE_BUTTON_1

src/EasyButtonAtInt01.hpp

@@ -15,7 +15,7 @@
  *  #include "EasyButtonAtInt01.hpp"
  *  EasyButton Button0AtPin2(true);
  *
- *  Copyright (C) 2018  Armin Joachimsmeyer
+ *  Copyright (C) 2018-2022  Armin Joachimsmeyer
  *  armin.joachimsmeyer@gmail.com
  *
  *  This file is part of EasyButtonAtInt01 https://github.com/ArminJo/EasyButtonAtInt01.
@@ -42,7 +42,7 @@
  * - USE_BUTTON_1                   Enables code for button at INT1 (pin3 on 328P, PA3 on ATtiny167, PCINT0 / PCx for ATtinyX5).
  * - BUTTON_IS_ACTIVE_HIGH          Enable this if you buttons are active high.
  * - USE_ATTACH_INTERRUPT           This forces use of the arduino function attachInterrupt(). It is required if you get the error "multiple definition of __vector_1".
- * - NO_BUTTON_RELEASE_CALLBACK     Disables the code for release callback. This saves 2 bytes RAM and 64 bytes FLASH.
+ * - NO_BUTTON_RELEASE_CALLBACK     Disables the code for release callback. This saves 2 bytes RAM and 64 bytes program space.
  * - BUTTON_DEBOUNCING_MILLIS       With this you can adapt to the characteristic of your button.
  * - ANALYZE_MAX_BOUNCING_PERIOD    Analyze the buttons actual debounce value.
  * - BUTTON_LED_FEEDBACK            This activates LED_BUILTIN as long as button is pressed.
@@ -458,13 +458,19 @@ bool EasyButton::checkForLongPressBlocking(uint16_t aLongPressThresholdMillis) {
  * Double press detection by computing difference between current (active) timestamp ButtonLastChangeMillis
  * and last release timestamp ButtonReleaseMillis.
  * !!!Works only reliable if called early in ButtonPress callback function!!!
- * Be aware, that the first press after booting may be detected as double press!
- * This is because ButtonReleaseMillis is initialized with 0 milliseconds, which is interpreted as the first press happened at the beginning of boot.
  * @return true if double press detected.
  */
 bool EasyButton::checkForDoublePress(uint16_t aDoublePressDelayMillis) {
-    unsigned long tReleaseToPressTimeMillis = ButtonLastChangeMillis - ButtonReleaseMillis;
-    return (tReleaseToPressTimeMillis <= aDoublePressDelayMillis);
+    /*
+     * Check if ButtonReleaseMillis is not in initialized state
+     * otherwise a single press before aDoublePressDelayMillis after boot is mistakenly detected as double press
+     */
+    if (ButtonReleaseMillis != 0) {
+        // because ButtonReleaseMillis is initialized with 0 milliseconds, which is interpreted as the first press happened at the beginning of boot.
+        unsigned long tReleaseToPressTimeMillis = ButtonLastChangeMillis - ButtonReleaseMillis;
+        return (tReleaseToPressTimeMillis <= aDoublePressDelayMillis);
+    }
+    return false;
 }
 
 /*