text: /*
   * Copyright (c) 2021 Ruslan V. Uss <unclerus@gmail.com>
   *
   * 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 itscontributors
   *    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.
   */
  
  /**
   * @file wiegand.h
   * @defgroup wiegand wiegand
   * @{
   *
   * ESP-IDF Wiegand protocol receiver
   *
   * Copyright (c) 2021 Ruslan V. Uss <unclerus@gmail.com>
   *
   * BSD Licensed as described in the file LICENSE
   */
  #ifndef __WIEGAND_H__
  #define __WIEGAND_H__
  
  #include <driver/gpio.h>
  #include <esp_err.h>
  #include <esp_timer.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  typedef struct wiegand_reader wiegand_reader_t;
  
  typedef void (*wiegand_callback_t)(wiegand_reader_t *reader);
  
  /**
   * Wiegand reader descriptor
   */
  struct wiegand_reader
  {
      gpio_num_t gpio_d0, gpio_d1;
      wiegand_callback_t callback;
  
      uint8_t *buf;
      size_t size;
      size_t bits;
      esp_timer_handle_t timer;
      bool start_parity;
  };
  
  /**
   * @brief Create and initialize reader instance.
   *
   * @param reader           Reader descriptor
   * @param gpio_d0          GPIO pin for D0
   * @param gpio_d1          GPIO pin for D0
   * @param internal_pullups Enable internal pull-up resistors for D0 and D1 GPIO
   * @param buf_size         Reader buffer size in bytes, must be large enough to
   *                         contain entire Wiegand key
   * @param callback         Callback function for processing received codes
   * @return `ESP_OK` on success
   */
  esp_err_t wiegand_reader_init(wiegand_reader_t *reader, gpio_num_t gpio_d0, gpio_num_t gpio_d1,
          bool internal_pullups, size_t buf_size, wiegand_callback_t callback);
  
  /**
   * @brief Delete reader instance.
   *
   * @param reader Reader descriptor
   * @return `ESP_OK` on success
   */
  esp_err_t wiegand_reader_done(wiegand_reader_t *reader);
  
  #ifdef __cplusplus
  }
  #endif
  
  /**@}*/
  
  #endif /* __WIEGAND_H__ */
  