locator_receiver/utility/DigitalOutput.h

   1 /* Arduino SSD1306Ascii Library
   2  * Copyright (C) 2015 by William Greiman
   3  *
   4  * This file is part of the Arduino SSD1306Ascii Library
   5  *
   6  * This Library is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This Library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with the Arduino SSD1306Ascii Library.  If not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20 /**
  21  * @file DigitalOutput.h
  22  * @brief Faster version of digitalWrite().
  23  */
  24 #ifndef DigitalOutput_h
  25 #define DigitalOutput_h
  26
  27 #include <Arduino.h>
  28 #ifdef __AVR__
  29 #include <util/atomic.h>
  30 #include <avr/io.h>
  31 /**
  32  * @class DigitalOutput
  33  * @brief Faster version of digitalWrite().
  34  */
  35 class DigitalOutput {
  36  public:
  37   /**
  38    * @breif initialize the digital pin.
  39    *
  40    * @param[in] pin The Arduino pin number.
  41    */
  42   void begin(uint8_t pin) {
  43     uint8_t port = digitalPinToPort(pin);
  44     m_portReg = portOutputRegister(port);
  45     m_bit = digitalPinToBitMask(pin);
  46     m_mask = ~m_bit;
  47     pinMode(pin, OUTPUT);
  48   }
  49   /**
  50    * @brief Set the level of a digital pin.
  51    *
  52    * @param[in] level The value to be set.
  53    */
  54   inline __attribute__((always_inline))
  55   void write(bool level) {ATOMIC_BLOCK(ATOMIC_FORCEON) {writeI(level);}}
  56   /**
  57    * @brief Set the level of a digital pin.
  58    *
  59    * @param[in] level The value to be set.
  60    * @note This function must be called with interrupts disabled.
  61    */
  62   inline __attribute__((always_inline))
  63   void writeI(bool level) {
  64     *m_portReg = level ? *m_portReg | m_bit : *m_portReg & m_mask;
  65   }
  66
  67  private:
  68   uint8_t m_bit;
  69   uint8_t m_mask;
  70   volatile uint8_t* m_portReg;
  71 };
  72 #else  // _AVR_
  73 /**
  74  * @class DigitalOutput
  75  * @brief Non AVR version of digitalWrite().
  76  */
  77 class DigitalOutput {
  78  public:
  79   /**
  80    * @brief initialize the digital pin.
  81    *
  82    * @param[in] pin The Arduino pin number.
  83    */
  84   void begin(uint8_t pin) {
  85     m_pin = pin;
  86     pinMode(m_pin, OUTPUT);
  87   }
  88   /**
  89    * @brief Set the level of a digital pin.
  90    *
  91    * @param[in] level The value to be set.
  92    */
  93   inline __attribute__((always_inline))
  94   void write(bool level) {
  95     digitalWrite(m_pin, level);
  96   }
  97  private:
  98   uint8_t m_pin;
  99 };
 100 #endif  // _AVR_
 101 #endif  // DigitalOutput_h