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

88 lines
3.2 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019 Lucian Copeland 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 "shared-bindings/pulseio/PulseOut.h"
#include "shared-bindings/pwmio/PWMOut.h"
#include "py/runtime.h"
// Requires rmt.c void peripherals_reset_all(void) to reset
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t *self,
const mcu_pin_obj_t *pin,
uint32_t frequency,
uint16_t duty_cycle) {
rmt_channel_t channel = peripherals_find_and_reserve_rmt(TRANSMIT_MODE);
if (channel == RMT_CHANNEL_MAX) {
mp_raise_RuntimeError(MP_ERROR_TEXT("All timers in use"));
}
// Configure Channel
rmt_config_t config = RMT_DEFAULT_CONFIG_TX(pin->number, channel);
config.tx_config.carrier_en = true;
config.tx_config.carrier_duty_percent = (duty_cycle * 100) / (1 << 16);
config.tx_config.carrier_freq_hz = frequency;
config.clk_div = 80;
rmt_config(&config);
rmt_driver_install(channel, 0, 0);
self->channel = channel;
}
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t *self) {
return self->channel == RMT_CHANNEL_MAX;
}
void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t *self) {
peripherals_free_rmt(self->channel);
self->channel = RMT_CHANNEL_MAX;
}
void common_hal_pulseio_pulseout_send(pulseio_pulseout_obj_t *self, uint16_t *pulses, uint16_t length) {
rmt_item32_t items[length];
// Circuitpython allows 16 bit pulse values, while ESP32 only allows 15 bits
// Thus, we use entire items for one pulse, rather than switching inside each item
for (size_t i = 0; i < length; i++) {
// Setting the RMT duration to 0 has undefined behavior, so avoid that pre-emptively.
if (pulses[i] == 0) {
pulses[i] = 1;
}
uint32_t level = (i % 2) ? 0 : 1;
const rmt_item32_t item = {{{ (pulses[i] & 0x8000 ? 0x7FFF : 1), level, (pulses[i] & 0x7FFF), level}}};
items[i] = item;
}
rmt_write_items(self->channel, items, length, true);
while (rmt_wait_tx_done(self->channel, 0) != ESP_OK) {
RUN_BACKGROUND_TASKS;
}
}