circuitpython/ports/raspberrypi/common-hal/pulseio/PulseOut.c

113 lines
3.8 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Dave Putz for Adafruit Industries
*
* 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 "common-hal/pulseio/PulseOut.h"
#include <stdint.h>
#include "mpconfigport.h"
#include "py/runtime.h"
#include "shared-bindings/pulseio/PulseOut.h"
#include "shared-bindings/pwmio/PWMOut.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "common-hal/pwmio/PWMOut.h"
#include "supervisor/shared/translate.h"
#include "src/rp2_common/hardware_pwm/include/hardware/pwm.h"
#include "src/common/pico_time/include/pico/time.h"
static uint8_t refcount = 0;
static uint16_t *pulse_buffer = NULL;
static volatile uint16_t pulse_index = 0;
static uint16_t pulse_length;
pwmio_pwmout_obj_t *pwmout_obj;
volatile uint16_t current_duty_cycle;
void pulse_finish(void) {
pulse_index++;
// Turn pwm pin off by setting duty cyle to 1.
common_hal_pwmio_pwmout_set_duty_cycle(pwmout_obj,1);
if (pulse_index >= pulse_length) {
return;
}
add_alarm_in_us(pulse_buffer[pulse_index], pulseout_interrupt_handler, NULL, false);
if (pulse_index % 2 == 0) {
common_hal_pwmio_pwmout_set_duty_cycle(pwmout_obj,current_duty_cycle);
}
}
int64_t pulseout_interrupt_handler(alarm_id_t id, void *user_data) {
pulse_finish();
return 0;
}
void pulseout_reset() {
refcount = 0;
}
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t *self,
const pwmio_pwmout_obj_t *carrier,
const mcu_pin_obj_t *pin,
uint32_t frequency,
uint16_t duty_cycle) {
refcount++;
pwmout_obj = (pwmio_pwmout_obj_t *)carrier;
current_duty_cycle = common_hal_pwmio_pwmout_get_duty_cycle(pwmout_obj);
self->pin = carrier->pin->number;
self->slice = carrier->slice;
pwm_set_enabled(pwmout_obj->slice,false);
}
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t *self) {
return self->pin == NO_PIN;
}
void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t *self) {
if (common_hal_pulseio_pulseout_deinited(self)) {
return;
}
refcount--;
self->pin = NO_PIN;
}
void common_hal_pulseio_pulseout_send(pulseio_pulseout_obj_t *self, uint16_t *pulses, uint16_t length) {
pulse_buffer = pulses;
pulse_index = 0;
pulse_length = length;
add_alarm_in_us(pulses[0], pulseout_interrupt_handler, NULL, false);
common_hal_pwmio_pwmout_set_duty_cycle(pwmout_obj,current_duty_cycle);
pwm_set_enabled(pwmout_obj->slice,true);
while (pulse_index < length) {
// Do other things while we wait. The interrupts will handle sending the
// signal.
RUN_BACKGROUND_TASKS;
}
// Short delay to give pin time to settle before disabling PWM
common_hal_mcu_delay_us(25);
pwm_set_enabled(pwmout_obj->slice,false);
}