From 0dbd6516b212a526eaecf3540d71ac31450d6386 Mon Sep 17 00:00:00 2001 From: Jack Christensen Date: Wed, 21 Mar 2012 18:05:07 -0400 Subject: [PATCH] initial commit --- button.cpp | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++ button.h | 40 +++++++++++++++++ keywords.txt | 9 ++++ 3 files changed, 168 insertions(+) create mode 100644 button.cpp create mode 100644 button.h create mode 100644 keywords.txt diff --git a/button.cpp b/button.cpp new file mode 100644 index 0000000..2957b49 --- /dev/null +++ b/button.cpp @@ -0,0 +1,119 @@ +/*----------------------------------------------------------------------* + * button.cpp -- Library for reading momentary contact switches like * + * tactile button switches. Intended for use in state machine * + * constructs. Use the read() function to read all buttons in the * + * main loop, which should execute as fast as possible, or at least * + * very frequently. * + * * + * Jack Christensen 11May2011 * + * * + * This work is licensed under the Creative Commons Attribution- * + * ShareAlike 3.0 Unported License. To view a copy of this license, * + * visit http://creativecommons.org/licenses/by-sa/3.0/ or send a * + * letter to Creative Commons, 171 Second Street, Suite 300, * + * San Francisco, California, 94105, USA. * + *----------------------------------------------------------------------*/ +#include "WProgram.h" +#include "button.h" + +//the constructor button(pin, puEnabled, invert, dbTime) instantiates a button object. +//pin is the Arduino pin the button is connected to. +//puEnabled enables the AVR internal pullup resistor if != 0 (can use true or false). +//invert = 0 interprets a high state as pressed, low as released. +//invert != 0 interprets a high state as released, low as pressed (can use true or false). +//dbTime is the debounce time in milliseconds. +//note that invert cannot be implied from puEnabled since an external pullup could be used. +button::button(uint8_t pin, uint8_t puEnabled, uint8_t invert, uint32_t dbTime) +{ + _pin = pin; + _puEnabled = puEnabled; + _invert = invert; + _dbTime = dbTime; + pinMode(_pin, INPUT); + if (_puEnabled != 0) + digitalWrite(_pin, HIGH); //enable pullup resistor + _state = digitalRead(_pin); + if (_invert != 0) _state = !_state; + _time = millis(); + _lastState = _state; + _changed = 0; + _lastTime = _time; + _lastChange = _time; +} + +//read() returns the state of the button 1 (pressed), or 0 (released), +//does debouncing, and also captures and maintains times, previous states, etc. +uint8_t button::read(void) +{ + static uint32_t ms; + static uint8_t pinVal; + + ms = millis(); + pinVal = digitalRead(_pin); + if (_invert != 0) pinVal = !pinVal; + if (ms < _lastChange + _dbTime) { + _lastTime = _time; + _time = ms; + _changed = 0; + return _state; + } + else { + _lastTime = _time; + _lastState = _state; + _state = pinVal; + _time = ms; + if (_state != _lastState) { + _lastChange = ms; + _changed = 1; + } + else { + _changed = 0; + } + return _state; + } +} + +//isPressed() and isReleased() check the button state when it was last read, +//and return false (0) or true (!=0) accordingly. +//These functions do not cause the button to be read. +uint8_t button::isPressed(void) +{ + return _state == 0 ? 0 : 1; +} + +uint8_t button::isReleased(void) +{ + return _state == 0 ? 1 : 0; +} + +//wasPressed() and wasReleased() check the button state to see if it changed +//between the last two reads and return false (0) or true (!=0) accordingly. +//These functions do not cause the button to be read. +uint8_t button::wasPressed(void) +{ + return _state && _changed; +} + +uint8_t button::wasReleased(void) +{ + return !_state && _changed; +} + +//pressedFor(ms) and releasedFor(ms) check to see if the button is pressed (or released), +//and has been in that state for the specified time. Returns false (0) or true (1) accordingly. +//These functions do not cause the button to be read. +uint8_t button::pressedFor(uint32_t ms) +{ + return (_state == 1 && _time - _lastChange >= ms) ? 1 : 0; +} + +uint8_t button::releasedFor(uint32_t ms) +{ + return (_state == 0 && _time - _lastChange >= ms) ? 1 : 0; +} + +//lastChange() returns the time of the last state change in milliseconds. +uint32_t button::lastChange(void) +{ + return _lastChange; +} diff --git a/button.h b/button.h new file mode 100644 index 0000000..1836065 --- /dev/null +++ b/button.h @@ -0,0 +1,40 @@ +/*----------------------------------------------------------------------* + * button.h -- Library for reading momentary contact switches like * + * tactile button switches. * + * * + * Jack Christensen 11 May 2011 * + * * + * This work is licensed under the Creative Commons Attribution- * + * ShareAlike 3.0 Unported License. To view a copy of this license, * + * visit http://creativecommons.org/licenses/by-sa/3.0/ or send a * + * letter to Creative Commons, 171 Second Street, Suite 300, * + * San Francisco, California, 94105, USA. * + *----------------------------------------------------------------------*/ +#ifndef button_h +#define button_h +#include "WProgram.h" +class button +{ + public: + button(uint8_t pin, uint8_t puEnabled, uint8_t invert, uint32_t dbTime); + uint8_t read(); + uint8_t isPressed(); + uint8_t isReleased(); + uint8_t wasPressed(); + uint8_t wasReleased(); + uint8_t pressedFor(uint32_t ms); + uint8_t releasedFor(uint32_t ms); + uint32_t lastChange(); + private: + uint8_t _pin; //arduino pin number + uint8_t _puEnabled; //internal pullup resistor enabled + uint8_t _invert; //if 0, interpret high state as pressed, else interpret low state as pressed + uint8_t _state; //current button state + uint8_t _lastState; //previous button state + uint8_t _changed; //state changed since last read + uint32_t _time; //time of current state (all times are in ms) + uint32_t _lastTime; //time of previous state + uint32_t _lastChange; //time of last state change + uint32_t _dbTime; //debounce time +}; +#endif \ No newline at end of file diff --git a/keywords.txt b/keywords.txt new file mode 100644 index 0000000..3e2c026 --- /dev/null +++ b/keywords.txt @@ -0,0 +1,9 @@ +button KEYWORD1 +read KEYWORD2 +isPressed KEYWORD2 +isReleased KEYWORD2 +wasPressed KEYWORD2 +wasReleased KEYWORD2 +pressedFor KEYWORD2 +releasedFor KEYWORD2 +lastChange KEYWORD2 \ No newline at end of file