FilesExpand file tree

 main

/

machine_pulse.c

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

44 lines (39 loc) · 1.43 KB

 main

/

machine_pulse.c

Top

File metadata and controls

• Code
• Blame

44 lines (39 loc) · 1.43 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

// SPDX-FileCopyrightText: 2014 MicroPython & CircuitPython contributors (https://github.com/adafruit/circuitpython/graphs/contributors)

// SPDX-FileCopyrightText: Copyright (c) 2016 Damien P. George

//

// SPDX-License-Identifier: MIT

#include "py/runtime.h"

#include "py/mperrno.h"

#include "extmod/machine_pulse.h"

#if MICROPY_PY_MACHINE_PULSE

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