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Add more PWMOut examples and rename the duty constructor argument 

to duty_cycle so that its consistent with the attribute.

Fixes #84
This commit is contained in:
Scott Shawcroft 2017-02-01 15:07:31 -08:00
parent 1da14b0eec
commit 9f6da7b2fe
1 changed files with 28 additions and 4 deletions
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32
shared-bindings/nativeio/PWMOut.c
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@ -38,24 +38,48 @@
//|
//| PWMOut can be used to output a PWM signal on a given pin.
//|
//| .. class:: PWMOut(pin, duty=0, frequency=500, variable_frequency=False)
//| .. class:: PWMOut(pin, duty_cycle=0, frequency=500, variable_frequency=False)
//|
//| 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: 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
//|
//| Example usage::
//| Simple LED fade::
//|
//| import nativeio
//| import board
//|
//| with nativeio.PWMOut(board.D13) as pwm: # output on D13
//| pwm.duty_cycle = 2 ** 15 # Cycles the pin with 50% duty cycle (half of 2 ** 16)
//| pwm.duty_cycle = 2 ** 15 # Cycles the pin with 50% duty cycle (half of 2 ** 16) at the default 500hz
//|
//| PWM at specific frequency (servos and motors)::
//|
//| import nativeio
//| import board
//|
//| with nativeio.PWMOut(board.D13, frequency=50) as pwm:
//| pwm.duty_cycle = 2 ** 15 # Cycles the pin with 50% duty cycle (half of 2 ** 16) at 50hz
//|
//| Variable frequency (usually tones)::
//|
//| import nativeio
//| import board
//| import time
//|
//| with nativeio.PWMOut(board.D13, duty_cycle=2 ** 15, frequency=440, variable_frequency=True) as pwm:
//| time.sleep(0.2)
//| pwm.frequency = 880
//| time.sleep(0.1)
//|
STATIC mp_obj_t nativeio_pwmout_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
@ -72,7 +96,7 @@ STATIC mp_obj_t nativeio_pwmout_make_new(const mp_obj_type_t *type, size_t n_arg
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
enum { ARG_duty, ARG_frequency, ARG_variable_frequency };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_duty, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ 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} },
};