.. _program_listing_file_src_encoder.h:

Program Listing for File encoder.h
==================================

|exhale_lsh| :ref:`Return to documentation for file <file_src_encoder.h>` (``src/encoder.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // Code in this file is inspired by:
   // https://github.com/hbrobotics/ros_arduino_bridge/blob/indigo-devel/ros_arduino_firmware/src/libraries/ROSArduinoBridge/encoder_driver.h
   //
   // ----------------------------------------------------------------------------
   // ros_arduino_bridge's license follows:
   //
   // Software License Agreement (BSD License)
   //
   // Copyright (c) 2012, Patrick Goebel.
   // All rights reserved.
   //
   // Redistribution and use in source and binary forms, with or without
   // modification, are permitted provided that the following conditions
   // are met:
   //
   //   * Redistributions of source code must retain the above copyright
   //     notice, this list of conditions and the following disclaimer.
   //   * Redistributions in binary form must reproduce the above
   //     copyright notice, this list of conditions and the following
   //     disclaimer in the documentation and/or other materials provided
   //     with the distribution.
   //
   // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   // COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   // POSSIBILITY OF SUCH DAMAGE.
   
   // BSD 3-Clause License
   //
   // Copyright (c) 2023, Ekumen Inc.
   // All rights reserved.
   //
   // Redistribution and use in source and binary forms, with or without
   // modification, are permitted provided that the following conditions are met:
   //
   // 1. Redistributions of source code must retain the above copyright notice, this
   //    list of conditions and the following disclaimer.
   //
   // 2. Redistributions in binary form must reproduce the above copyright notice,
   //    this list of conditions and the following disclaimer in the documentation
   //    and/or other materials provided with the distribution.
   //
   // 3. Neither the name of the copyright holder nor the names of its
   //    contributors may be used to endorse or promote products derived from
   //    this software without specific prior written permission.
   //
   // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   #pragma once
   
   #include <stdint.h>
   
   #include "interrupt_in.h"
   
   namespace andino {
   
   class Encoder {
    public:
     Encoder(const InterruptIn* channel_a_interrupt_in, const InterruptIn* channel_b_interrupt_in)
         : channel_a_interrupt_in_(channel_a_interrupt_in),
           channel_b_interrupt_in_(channel_b_interrupt_in) {}
   
     void begin();
   
     long read();
   
     void reset();
   
    private:
     static constexpr int8_t kTicksDelta[]{0, 1, -1, 0, -1, 0, 0, 1, 1, 0, 0, -1, 0, -1, 1, 0};
   
     static constexpr int kInstancesMax{2};
   
     static const InterruptIn::InterruptCallback kCallbacks[kInstancesMax];
   
     static void callback_0();
   
     static void callback_1();
   
     void callback();
   
     static Encoder* instances_[kInstancesMax];
   
     static int instance_count_;
   
     const InterruptIn* channel_a_interrupt_in_;
   
     const InterruptIn* channel_b_interrupt_in_;
   
     uint8_t state_{0x00};
   
     volatile long count_{0L};
   };
   
   }  // namespace andino