1 /*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2016 Damien P. George
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27 #include "py/runtime.h"
28 #include "py/mperrno.h"
29 #include "extmod/machine_pulse.h"
30
31 #if MICROPY_PY_MACHINE_PULSE
32
machine_time_pulse_us(mp_hal_pin_obj_t pin,int pulse_level,mp_uint_t timeout_us)33 MP_WEAK mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us) {
34 mp_uint_t start = mp_hal_ticks_us();
35 while (mp_hal_pin_read(pin) != pulse_level) {
36 if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
37 return (mp_uint_t)-2;
38 }
39 }
40 start = mp_hal_ticks_us();
41 while (mp_hal_pin_read(pin) == pulse_level) {
42 if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout_us) {
43 return (mp_uint_t)-1;
44 }
45 }
46 return mp_hal_ticks_us() - start;
47 }
48
machine_time_pulse_us_(size_t n_args,const mp_obj_t * args)49 STATIC mp_obj_t machine_time_pulse_us_(size_t n_args, const mp_obj_t *args) {
50 mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(args[0]);
51 int level = 0;
52 if (mp_obj_is_true(args[1])) {
53 level = 1;
54 }
55 mp_uint_t timeout_us = 1000000;
56 if (n_args > 2) {
57 timeout_us = mp_obj_get_int(args[2]);
58 }
59 mp_uint_t us = machine_time_pulse_us(pin, level, timeout_us);
60 // May return -1 or -2 in case of timeout
61 return mp_obj_new_int(us);
62 }
63 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_time_pulse_us_obj, 2, 3, machine_time_pulse_us_);
64
65 #endif
66