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Commit 4940bee

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dpgeorgedpgeorge
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extmod: Add machine time_pulse_us function (at C and Python level).
The C implementation is taken from the DHT driver.
1 parent 298c2ae commit 4940bee

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4 files changed

+108
-18
lines changed

4 files changed

+108
-18
lines changed

‎drivers/dht/dht.c

+3-18
Original file line numberDiff line numberDiff line change
@@ -29,24 +29,9 @@
2929
#include "py/runtime.h"
3030
#include "py/mperrno.h"
3131
#include "py/mphal.h"
32+
#include "extmod/machine_pulse.h"
3233
#include "drivers/dht/dht.h"
3334

34-
STATIC mp_uint_t time_pulse_us(mp_hal_pin_obj_t pin, int pulse_value, mp_uint_t timeout) {
35-
mp_uint_t start = mp_hal_ticks_us();
36-
while (mp_hal_pin_read(pin) != pulse_value) {
37-
if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout) {
38-
return (mp_uint_t)-1;
39-
}
40-
}
41-
start = mp_hal_ticks_us();
42-
while (mp_hal_pin_read(pin) == pulse_value) {
43-
if ((mp_uint_t)(mp_hal_ticks_us() - start) >= timeout) {
44-
return (mp_uint_t)-1;
45-
}
46-
}
47-
return mp_hal_ticks_us() - start;
48-
}
49-
5035
STATIC mp_obj_t dht_readinto(mp_obj_t pin_in, mp_obj_t buf_in) {
5136
mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(pin_in);
5237
mp_hal_pin_open_drain(pin);
@@ -79,15 +64,15 @@ STATIC mp_obj_t dht_readinto(mp_obj_t pin_in, mp_obj_t buf_in) {
7964
}
8065

8166
// time pulse, should be 80us
82-
ticks = time_pulse_us(pin, 1, 150);
67+
ticks = machine_time_pulse_us(pin, 1, 150);
8368
if (ticks == (mp_uint_t)-1) {
8469
goto timeout;
8570
}
8671

8772
// time 40 pulses for data (either 26us or 70us)
8873
uint8_t *buf = bufinfo.buf;
8974
for (int i = 0; i < 40; ++i) {
90-
ticks = time_pulse_us(pin, 1, 100);
75+
ticks = machine_time_pulse_us(pin, 1, 100);
9176
if (ticks == (mp_uint_t)-1) {
9277
goto timeout;
9378
}

‎extmod/machine_pulse.c

+67
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,67 @@
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
32+
33+
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)-1;
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+
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+
if (us == (mp_uint_t)-1) {
61+
nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(MP_ETIMEDOUT)));
62+
}
63+
return mp_obj_new_int(us);
64+
}
65+
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_time_pulse_us_obj, 2, 3, machine_time_pulse_us_);
66+
67+
#endif

‎extmod/machine_pulse.h

+37
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,37 @@
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+
#ifndef __MICROPY_INCLUDED_EXTMOD_MACHINE_PULSE_H__
28+
#define __MICROPY_INCLUDED_EXTMOD_MACHINE_PULSE_H__
29+
30+
#include "py/obj.h"
31+
#include "py/mphal.h"
32+
33+
mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us);
34+
35+
MP_DECLARE_CONST_FUN_OBJ(machine_time_pulse_us_obj);
36+
37+
#endif // __MICROPY_INCLUDED_EXTMOD_MACHINE_PULSE_H__

‎py/py.mk

+1
Original file line numberDiff line numberDiff line change
@@ -176,6 +176,7 @@ PY_O_BASENAME = \
176176
../extmod/modubinascii.o \
177177
../extmod/virtpin.o \
178178
../extmod/machine_mem.o \
179+
../extmod/machine_pulse.o \
179180
../extmod/machine_i2c.o \
180181
../extmod/modussl.o \
181182
../extmod/modurandom.o \

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