text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2016 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include "py/runtime.h"
  #include "py/mperrno.h"
  #include "machine_pulse.h"
  
  #if MICROPY_PY_MACHINE_PULSE
  
  MP_WEAK mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us) {
      mp_uint_t start = mp_hal_ticks_us();
      while (mp_hal_pin_read(pin) != pulse_level) {
          if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
              return (mp_uint_t)-2;
          }
      }
      start = mp_hal_ticks_us();
      while (mp_hal_pin_read(pin) == pulse_level) {
          if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
              return (mp_uint_t)-1;
          }
      }
      return mp_hal_ticks_us() - start;
  }
  
  STATIC mp_obj_t machine_time_pulse_us_(size_t n_args, const mp_obj_t *args) {
      mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(args[0]);
      int level = 0;
      if (mp_obj_is_true(args[1])) {
          level = 1;
      }
      mp_uint_t timeout_us = 1000000;
      if (n_args > 2) {
          timeout_us = mp_obj_get_int(args[2]);
      }
      mp_uint_t us = machine_time_pulse_us(pin, level, timeout_us);
      // May return -1 or -2 in case of timeout
      return mp_obj_new_int(us);
  }
  MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_time_pulse_us_obj, 2, 3, machine_time_pulse_us_);
  
  #endif
  