Add Ticker library (#1057)

* Add Ticker library

* Fix CI (#1)

remove LED_BUILTIN in examples

libraries/Ticker/examples/Arguments/Arguments.ino

+#include <Arduino.h>
+#include <Ticker.h>
+
+// attach a LED to GPIO 21
+#define LED_PIN 21
+
+Ticker tickerSetHigh;
+Ticker tickerSetLow;
+
+void setPin(int state) {
+  digitalWrite(LED_PIN, state);
+}
+
+void setup() {
+  pinMode(LED_PIN, OUTPUT);
+  digitalWrite(1, LOW);
+  
+  // every 25 ms, call setPin(0) 
+  tickerSetLow.attach_ms(25, setPin, 0);
+  
+  // every 26 ms, call setPin(1)
+  tickerSetHigh.attach_ms(26, setPin, 1);
+}
+
+void loop() {
+
+}

libraries/Ticker/examples/Blinker/Blinker.ino

+#include <Arduino.h>
+#include <Ticker.h>
+
+// attach a LED to pPIO 21
+#define LED_PIN 21
+
+Ticker blinker;
+Ticker toggler;
+Ticker changer;
+float blinkerPace = 0.1;  //seconds
+const float togglePeriod = 5; //seconds
+
+void change() {
+  blinkerPace = 0.5;
+}
+
+void blink() {
+  digitalWrite(LED_PIN, !digitalRead(LED_PIN));
+}
+
+void toggle() {
+  static bool isBlinking = false;
+  if (isBlinking) {
+    blinker.detach();
+    isBlinking = false;
+  }
+  else {
+    blinker.attach(blinkerPace, blink);
+    isBlinking = true;
+  }
+  digitalWrite(LED_PIN, LOW);  //make sure LED on on after toggling (pin LOW = led ON)
+}
+
+void setup() {
+  pinMode(LED_PIN, OUTPUT);
+  toggler.attach(togglePeriod, toggle);
+  changer.once(30, change);
+}
+
+void loop() {
+  
+}

libraries/Ticker/keywords.txt

+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+Ticker	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+attach	KEYWORD2
+attach_ms KEYWORD2
+once  KEYWORD2
+detach  KEYWORD2

libraries/Ticker/library.properties

+name=Ticker
+version=1.1
+author=Bert Melis
+maintainer=Hristo Gochkov <hristo@espressif.com>
+sentence=Allows to call functions with a given interval.
+paragraph=
+category=Timing
+url=
+architectures=esp32

libraries/Ticker/src/Ticker.cpp

+/* 
+  Ticker.cpp - esp32 library that calls functions periodically
+
+  Copyright (c) 2017 Bert Melis. All rights reserved.
+  
+  Based on the original work of:
+  Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
+  The original version is part of the esp8266 core for Arduino environment.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "Ticker.h"
+
+Ticker::Ticker() :
+  _timer(nullptr) {}
+
+Ticker::~Ticker() {
+  detach();
+}
+
+void Ticker::_attach_ms(uint32_t milliseconds, bool repeat, callback_with_arg_t callback, uint32_t arg) {
+  esp_timer_create_args_t _timerConfig;
+  _timerConfig.arg = reinterpret_cast<void*>(arg);
+  _timerConfig.callback = callback;
+  _timerConfig.dispatch_method = ESP_TIMER_TASK;
+  _timerConfig.name = "Ticker";
+  if (_timer) {
+    esp_timer_stop(_timer);
+    esp_timer_delete(_timer);
+  }
+  esp_timer_create(&_timerConfig, &_timer);
+  if (repeat) {
+    esp_timer_start_periodic(_timer, milliseconds * 1000);
+  } else {
+    esp_timer_start_once(_timer, milliseconds * 1000);
+  }
+}
+
+void Ticker::detach() {
+  if (_timer) {
+    esp_timer_stop(_timer);
+    esp_timer_delete(_timer);
+    _timer = nullptr;
+  }
+}

libraries/Ticker/src/Ticker.h

+/* 
+  Ticker.h - esp32 library that calls functions periodically
+
+  Copyright (c) 2017 Bert Melis. All rights reserved.
+  
+  Based on the original work of:
+  Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
+  The original version is part of the esp8266 core for Arduino environment.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef TICKER_H
+#define TICKER_H
+
+extern "C" {
+  #include "esp_timer.h"
+}
+
+class Ticker
+{
+public:
+  Ticker();
+  ~Ticker();
+  typedef void (*callback_t)(void);
+  typedef void (*callback_with_arg_t)(void*);
+
+  void attach(float seconds, callback_t callback)
+  {
+    _attach_ms(seconds * 1000, true, reinterpret_cast<callback_with_arg_t>(callback), 0);
+  }
+
+  void attach_ms(uint32_t milliseconds, callback_t callback)
+  {
+    _attach_ms(milliseconds, true, reinterpret_cast<callback_with_arg_t>(callback), 0);
+  }
+
+  template<typename TArg>
+  void attach(float seconds, void (*callback)(TArg), TArg arg)
+  {
+    static_assert(sizeof(TArg) <= sizeof(uint32_t), "attach() callback argument size must be <= 4 bytes");
+    // C-cast serves two purposes:
+    // static_cast for smaller integer types,
+    // reinterpret_cast + const_cast for pointer types
+    uint32_t arg32 = (uint32_t)arg;
+    _attach_ms(seconds * 1000, true, reinterpret_cast<callback_with_arg_t>(callback), arg32);
+  }
+
+  template<typename TArg>
+  void attach_ms(uint32_t milliseconds, void (*callback)(TArg), TArg arg)
+  {
+    static_assert(sizeof(TArg) <= sizeof(uint32_t), "attach_ms() callback argument size must be <= 4 bytes");
+    uint32_t arg32 = (uint32_t)arg;
+    _attach_ms(milliseconds, true, reinterpret_cast<callback_with_arg_t>(callback), arg32);
+  }
+
+  void once(float seconds, callback_t callback)
+  {
+    _attach_ms(seconds * 1000, false, reinterpret_cast<callback_with_arg_t>(callback), 0);
+  }
+
+  void once_ms(uint32_t milliseconds, callback_t callback)
+  {
+    _attach_ms(milliseconds, false, reinterpret_cast<callback_with_arg_t>(callback), 0);	
+  }
+
+  template<typename TArg>
+  void once(float seconds, void (*callback)(TArg), TArg arg)
+  {
+    static_assert(sizeof(TArg) <= sizeof(uint32_t), "attach() callback argument size must be <= 4 bytes");
+    uint32_t arg32 = (uint32_t)(arg);
+    _attach_ms(seconds * 1000, false, reinterpret_cast<callback_with_arg_t>(callback), arg32);
+  }
+
+  template<typename TArg>
+  void once_ms(uint32_t milliseconds, void (*callback)(TArg), TArg arg)
+  {
+    static_assert(sizeof(TArg) <= sizeof(uint32_t), "attach_ms() callback argument size must be <= 4 bytes");
+    uint32_t arg32 = (uint32_t)(arg);
+    _attach_ms(milliseconds, false, reinterpret_cast<callback_with_arg_t>(callback), arg32);
+  }
+
+  void detach();
+  bool active();
+
+protected:	
+  void _attach_ms(uint32_t milliseconds, bool repeat, callback_with_arg_t callback, uint32_t arg);
+
+
+protected:
+  esp_timer_handle_t _timer;
+};
+
+
+#endif  // TICKER_H