circuitpython/shared-bindings/pwmio/PWMOut.c

308 lines
13 KiB
C

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* SPDX-FileCopyrightText: 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 <stdint.h>
#include "shared/runtime/context_manager_helpers.h"
#include "py/objproperty.h"
#include "py/runtime.h"
#include "shared-bindings/microcontroller/Pin.h"
#include "shared-bindings/pwmio/PWMOut.h"
#include "shared-bindings/util.h"
void common_hal_pwmio_pwmout_raise_error(pwmout_result_t result) {
switch (result) {
case PWMOUT_OK:
break;
case PWMOUT_INVALID_PIN:
raise_ValueError_invalid_pin();
break;
case PWMOUT_INVALID_FREQUENCY:
mp_arg_error_invalid(MP_QSTR_frequency);
break;
case PWMOUT_INVALID_FREQUENCY_ON_PIN:
mp_raise_ValueError(MP_ERROR_TEXT("Frequency must match existing PWMOut using this timer"));
break;
case PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE:
mp_raise_ValueError(MP_ERROR_TEXT("Cannot vary frequency on a timer that is already in use"));
break;
case PWMOUT_ALL_TIMERS_ON_PIN_IN_USE:
mp_raise_ValueError(MP_ERROR_TEXT("All timers for this pin are in use"));
break;
case PWMOUT_ALL_TIMERS_IN_USE:
mp_raise_RuntimeError(MP_ERROR_TEXT("All timers in use"));
break;
case PWMOUT_ALL_CHANNELS_IN_USE:
mp_raise_RuntimeError(MP_ERROR_TEXT("All channels in use"));
break;
default:
case PWMOUT_INITIALIZATION_ERROR:
mp_raise_RuntimeError(MP_ERROR_TEXT("Could not start PWM"));
break;
}
}
//| class PWMOut:
//| """Output a Pulse Width Modulated signal on a given pin.
//|
//| .. note:: The exact frequencies possible depend on the specific microcontroller.
//| If the requested frequency is within the available range, one of the two
//| nearest possible frequencies to the requested one is selected.
//|
//| If the requested frequency is outside the range, either (A) a ValueError
//| may be raised or (B) the highest or lowest frequency is selected. This
//| behavior is microcontroller-dependent, and may depend on whether it's the
//| upper or lower bound that is exceeded.
//|
//| In any case, the actual frequency (rounded to 1Hz) is available in the
//| ``frequency`` property after construction.
//|
//| .. note:: The frequency is calculated based on a nominal CPU frequency.
//| However, depending on the board, the error between the nominal and
//| actual CPU frequency can be large (several hundred PPM in the case of
//| crystal oscillators and up to ten percent in the case of RC
//| oscillators)
//|
//| """
//|
//| def __init__(
//| self,
//| pin: microcontroller.Pin,
//| *,
//| duty_cycle: int = 0,
//| frequency: int = 500,
//| variable_frequency: bool = False
//| ) -> None:
//| """Create a PWM object associated with the given pin. This allows you to
//| write PWM signals out on the given pin. Frequency is fixed after init
//| unless ``variable_frequency`` is True.
//|
//| .. note:: When ``variable_frequency`` is True, further PWM outputs may be
//| limited because it may take more internal resources to be flexible. So,
//| when outputting both fixed and flexible frequency signals construct the
//| fixed outputs first.
//|
//| :param ~microcontroller.Pin pin: The pin to output to
//| :param int duty_cycle: The fraction of each pulse which is high. 16-bit
//| :param int frequency: The target frequency in Hertz (32-bit)
//| :param bool variable_frequency: True if the frequency will change over time
//|
//|
//| Simple LED on::
//|
//| import pwmio
//| import board
//|
//| pwm = pwmio.PWMOut(board.LED)
//|
//| while True:
//| pwm.duty_cycle = 2 ** 15 # Cycles the pin with 50% duty cycle (half of 2 ** 16) at the default 500hz
//|
//| PWM LED fade::
//|
//| import pwmio
//| import board
//|
//| pwm = pwmio.PWMOut(board.LED) # output on LED pin with default of 500Hz
//|
//| while True:
//| for cycle in range(0, 65535): # Cycles through the full PWM range from 0 to 65535
//| pwm.duty_cycle = cycle # Cycles the LED pin duty cycle through the range of values
//| for cycle in range(65534, 0, -1): # Cycles through the PWM range backwards from 65534 to 0
//| pwm.duty_cycle = cycle # Cycles the LED pin duty cycle through the range of values
//|
//| PWM at specific frequency (servos and motors)::
//|
//| import pwmio
//| import board
//|
//| pwm = pwmio.PWMOut(board.D13, frequency=50)
//| pwm.duty_cycle = 2 ** 15 # Cycles the pin with 50% duty cycle (half of 2 ** 16) at 50hz
//|
//| Variable frequency (usually tones)::
//|
//| import pwmio
//| import board
//| import time
//|
//| pwm = pwmio.PWMOut(board.D13, duty_cycle=2 ** 15, frequency=440, variable_frequency=True)
//| time.sleep(0.2)
//| pwm.frequency = 880
//| time.sleep(0.1)
//|
//| """
//| ...
STATIC mp_obj_t pwmio_pwmout_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
enum { ARG_pin, ARG_duty_cycle, ARG_frequency, ARG_variable_frequency };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_pin, MP_ARG_REQUIRED | MP_ARG_OBJ, },
{ MP_QSTR_duty_cycle, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 500} },
{ MP_QSTR_variable_frequency, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
};
mp_arg_val_t parsed_args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, args, MP_ARRAY_SIZE(allowed_args), allowed_args, parsed_args);
const mcu_pin_obj_t *pin = validate_obj_is_free_pin(parsed_args[ARG_pin].u_obj, MP_QSTR_pin);
uint16_t duty_cycle = parsed_args[ARG_duty_cycle].u_int;
uint32_t frequency = parsed_args[ARG_frequency].u_int;
bool variable_frequency = parsed_args[ARG_variable_frequency].u_bool;
// create PWM object from the given pin
pwmio_pwmout_obj_t *self = mp_obj_malloc(pwmio_pwmout_obj_t, &pwmio_pwmout_type);
pwmout_result_t result = common_hal_pwmio_pwmout_construct(self, pin, duty_cycle, frequency, variable_frequency);
common_hal_pwmio_pwmout_raise_error(result);
return MP_OBJ_FROM_PTR(self);
}
//| def deinit(self) -> None:
//| """Deinitialises the PWMOut and releases any hardware resources for reuse."""
//| ...
STATIC mp_obj_t pwmio_pwmout_deinit(mp_obj_t self_in) {
pwmio_pwmout_obj_t *self = MP_OBJ_TO_PTR(self_in);
common_hal_pwmio_pwmout_deinit(self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pwmio_pwmout_deinit_obj, pwmio_pwmout_deinit);
STATIC void check_for_deinit(pwmio_pwmout_obj_t *self) {
if (common_hal_pwmio_pwmout_deinited(self)) {
raise_deinited_error();
}
}
//| def __enter__(self) -> PWMOut:
//| """No-op used by Context Managers."""
//| ...
// Provided by context manager helper.
//| def __exit__(self) -> None:
//| """Automatically deinitializes the hardware when exiting a context. See
//| :ref:`lifetime-and-contextmanagers` for more info."""
//| ...
STATIC mp_obj_t pwmio_pwmout_obj___exit__(size_t n_args, const mp_obj_t *args) {
(void)n_args;
common_hal_pwmio_pwmout_deinit(args[0]);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pwmio_pwmout___exit___obj, 4, 4, pwmio_pwmout_obj___exit__);
//| duty_cycle: int
//| """16 bit value that dictates how much of one cycle is high (1) versus low
//| (0). 0xffff will always be high, 0 will always be low and 0x7fff will
//| be half high and then half low.
//|
//| Depending on how PWM is implemented on a specific board, the internal
//| representation for duty cycle might have less than 16 bits of resolution.
//| Reading this property will return the value from the internal representation,
//| so it may differ from the value set."""
STATIC mp_obj_t pwmio_pwmout_obj_get_duty_cycle(mp_obj_t self_in) {
pwmio_pwmout_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
return MP_OBJ_NEW_SMALL_INT(common_hal_pwmio_pwmout_get_duty_cycle(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(pwmio_pwmout_get_duty_cycle_obj, pwmio_pwmout_obj_get_duty_cycle);
STATIC mp_obj_t pwmio_pwmout_obj_set_duty_cycle(mp_obj_t self_in, mp_obj_t duty_cycle) {
pwmio_pwmout_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
mp_int_t duty = mp_obj_get_int(duty_cycle);
mp_arg_validate_int_range(duty, 0, 0xffff, MP_QSTR_duty_cycle);
common_hal_pwmio_pwmout_set_duty_cycle(self, duty);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(pwmio_pwmout_set_duty_cycle_obj, pwmio_pwmout_obj_set_duty_cycle);
MP_PROPERTY_GETSET(pwmio_pwmout_duty_cycle_obj,
(mp_obj_t)&pwmio_pwmout_get_duty_cycle_obj,
(mp_obj_t)&pwmio_pwmout_set_duty_cycle_obj);
//| frequency: int
//| """32 bit value that dictates the PWM frequency in Hertz (cycles per
//| second). Only writeable when constructed with ``variable_frequency=True``.
//|
//| Depending on how PWM is implemented on a specific board, the internal value
//| for the PWM's duty cycle may need to be recalculated when the frequency
//| changes. In these cases, the duty cycle is automatically recalculated
//| from the original duty cycle value. This should happen without any need
//| to manually re-set the duty cycle. However, an output glitch may occur during the adjustment.
//| """
//|
STATIC mp_obj_t pwmio_pwmout_obj_get_frequency(mp_obj_t self_in) {
pwmio_pwmout_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
return MP_OBJ_NEW_SMALL_INT(common_hal_pwmio_pwmout_get_frequency(self));
}
MP_DEFINE_CONST_FUN_OBJ_1(pwmio_pwmout_get_frequency_obj, pwmio_pwmout_obj_get_frequency);
STATIC mp_obj_t pwmio_pwmout_obj_set_frequency(mp_obj_t self_in, mp_obj_t frequency) {
pwmio_pwmout_obj_t *self = MP_OBJ_TO_PTR(self_in);
check_for_deinit(self);
if (!common_hal_pwmio_pwmout_get_variable_frequency(self)) {
mp_raise_AttributeError(MP_ERROR_TEXT(
"PWM frequency not writable when variable_frequency is False on construction."));
}
mp_int_t freq = mp_obj_get_int(frequency);
if (freq == 0) {
mp_arg_error_invalid(MP_QSTR_frequency);
}
common_hal_pwmio_pwmout_set_frequency(self, freq);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(pwmio_pwmout_set_frequency_obj, pwmio_pwmout_obj_set_frequency);
MP_PROPERTY_GETSET(pwmio_pwmout_frequency_obj,
(mp_obj_t)&pwmio_pwmout_get_frequency_obj,
(mp_obj_t)&pwmio_pwmout_set_frequency_obj);
STATIC const mp_rom_map_elem_t pwmio_pwmout_locals_dict_table[] = {
// Methods
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&pwmio_pwmout_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
{ MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&pwmio_pwmout___exit___obj) },
// Properties
{ MP_ROM_QSTR(MP_QSTR_duty_cycle), MP_ROM_PTR(&pwmio_pwmout_duty_cycle_obj) },
{ MP_ROM_QSTR(MP_QSTR_frequency), MP_ROM_PTR(&pwmio_pwmout_frequency_obj) },
// TODO(tannewt): Add enabled to determine whether the signal is output
// without giving up the resources. Useful for IR output.
};
STATIC MP_DEFINE_CONST_DICT(pwmio_pwmout_locals_dict, pwmio_pwmout_locals_dict_table);
MP_DEFINE_CONST_OBJ_TYPE(
pwmio_pwmout_type,
MP_QSTR_PWMOut,
MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS,
make_new, pwmio_pwmout_make_new,
locals_dict, &pwmio_pwmout_locals_dict
);