circuitpython/ports/esp32/esp32_rmt.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019 "Matt Trentini" <matt.trentini@gmail.com>
*
* 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 "py/runtime.h"
#include "modmachine.h"
#include "mphalport.h"
#include "driver/rmt.h"
// This exposes the ESP32's RMT module to MicroPython. RMT is provided by the Espressif ESP-IDF:
//
// https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/peripherals/rmt.html
//
// With some examples provided:
//
// https://github.com/espressif/arduino-esp32/tree/master/libraries/ESP32/examples/RMT
//
// RMT allows accurate (down to 12.5ns resolution) transmit - and receive - of pulse signals.
// Originally designed to generate infrared remote control signals, the module is very
// flexible and quite easy-to-use.
//
// This current MicroPython implementation lacks some major features, notably receive pulses
// and carrier output.
// Forward declaration
extern const mp_obj_type_t esp32_rmt_type;
typedef struct _esp32_rmt_obj_t {
mp_obj_base_t base;
uint8_t channel_id;
gpio_num_t pin;
uint8_t clock_div;
uint16_t carrier_duty_percent;
uint32_t carrier_freq;
mp_uint_t num_items;
rmt_item32_t *items;
bool loop_en;
} esp32_rmt_obj_t;
STATIC mp_obj_t esp32_rmt_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_pin, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_clock_div, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, // 100ns resolution
{ MP_QSTR_carrier_duty_percent, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 50} },
{ MP_QSTR_carrier_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_uint_t channel_id = args[0].u_int;
gpio_num_t pin_id = machine_pin_get_id(args[1].u_obj);
mp_uint_t clock_div = args[2].u_int;
bool carrier_en = false;
mp_uint_t carrier_duty_percent = 0;
mp_uint_t carrier_freq = 0;
if (args[4].u_int > 0) {
carrier_en = true;
carrier_duty_percent = args[3].u_int;
carrier_freq = args[4].u_int;
}
if (clock_div < 1 || clock_div > 255) {
mp_raise_ValueError(MP_ERROR_TEXT("clock_div must be between 1 and 255"));
}
esp32_rmt_obj_t *self = m_new_obj_with_finaliser(esp32_rmt_obj_t);
self->base.type = &esp32_rmt_type;
self->channel_id = channel_id;
self->pin = pin_id;
self->clock_div = clock_div;
self->carrier_duty_percent = carrier_duty_percent;
self->carrier_freq = carrier_freq;
self->loop_en = false;
rmt_config_t config = {0};
config.rmt_mode = RMT_MODE_TX;
config.channel = (rmt_channel_t)self->channel_id;
config.gpio_num = self->pin;
config.mem_block_num = 1;
config.tx_config.loop_en = 0;
config.tx_config.carrier_en = carrier_en;
config.tx_config.idle_output_en = 1;
config.tx_config.idle_level = 0;
config.tx_config.carrier_duty_percent = self->carrier_duty_percent;
config.tx_config.carrier_freq_hz = self->carrier_freq;
config.tx_config.carrier_level = 1;
config.clk_div = self->clock_div;
check_esp_err(rmt_config(&config));
check_esp_err(rmt_driver_install(config.channel, 0, 0));
return MP_OBJ_FROM_PTR(self);
}
STATIC void esp32_rmt_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
esp32_rmt_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (self->pin != -1) {
mp_printf(print, "RMT(channel=%u, pin=%u, source_freq=%u, clock_div=%u",
self->channel_id, self->pin, APB_CLK_FREQ, self->clock_div);
if (self->carrier_freq > 0) {
mp_printf(print, ", carrier_freq=%u, carrier_duty_percent=%u)",
self->carrier_freq, self->carrier_duty_percent);
} else {
mp_printf(print, ")");
}
} else {
mp_printf(print, "RMT()");
}
}
STATIC mp_obj_t esp32_rmt_deinit(mp_obj_t self_in) {
// fixme: check for valid channel. Return exception if error occurs.
esp32_rmt_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (self->pin != -1) { // Check if channel has already been deinitialised.
rmt_driver_uninstall(self->channel_id);
self->pin = -1; // -1 to indicate RMT is unused
m_free(self->items);
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_rmt_deinit_obj, esp32_rmt_deinit);
// Return the source frequency.
// Currently only the APB clock (80MHz) can be used but it is possible other
// clock sources will added in the future.
STATIC mp_obj_t esp32_rmt_source_freq(mp_obj_t self_in) {
return mp_obj_new_int(APB_CLK_FREQ);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_rmt_source_freq_obj, esp32_rmt_source_freq);
// Return the clock divider.
STATIC mp_obj_t esp32_rmt_clock_div(mp_obj_t self_in) {
esp32_rmt_obj_t *self = MP_OBJ_TO_PTR(self_in);
return mp_obj_new_int(self->clock_div);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_rmt_clock_div_obj, esp32_rmt_clock_div);
// Query whether the channel has finished sending pulses. Takes an optional
// timeout (in ticks of the 80MHz clock), returning true if the pulse stream has
// completed or false if they are still transmitting (or timeout is reached).
STATIC mp_obj_t esp32_rmt_wait_done(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_self, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
esp32_rmt_obj_t *self = MP_OBJ_TO_PTR(args[0].u_obj);
esp_err_t err = rmt_wait_tx_done(self->channel_id, args[1].u_int);
return err == ESP_OK ? mp_const_true : mp_const_false;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(esp32_rmt_wait_done_obj, 1, esp32_rmt_wait_done);
STATIC mp_obj_t esp32_rmt_loop(mp_obj_t self_in, mp_obj_t loop) {
esp32_rmt_obj_t *self = MP_OBJ_TO_PTR(self_in);
self->loop_en = mp_obj_get_int(loop);
if (!self->loop_en) {
bool loop_en;
check_esp_err(rmt_get_tx_loop_mode(self->channel_id, &loop_en));
if (loop_en) {
check_esp_err(rmt_set_tx_loop_mode(self->channel_id, false));
check_esp_err(rmt_set_tx_intr_en(self->channel_id, true));
}
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(esp32_rmt_loop_obj, esp32_rmt_loop);
STATIC mp_obj_t esp32_rmt_write_pulses(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_self, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_pulses, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = mp_const_none} },
{ MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
esp32_rmt_obj_t *self = MP_OBJ_TO_PTR(args[0].u_obj);
mp_obj_t pulses = args[1].u_obj;
mp_uint_t start = args[2].u_int;
if (start > 1) {
mp_raise_ValueError(MP_ERROR_TEXT("start must be 0 or 1"));
}
size_t pulses_length = 0;
mp_obj_t *pulses_ptr = NULL;
mp_obj_get_array(pulses, &pulses_length, &pulses_ptr);
mp_uint_t num_items = (pulses_length / 2) + (pulses_length % 2);
if (num_items > self->num_items) {
self->items = (rmt_item32_t *)m_realloc(self->items, num_items * sizeof(rmt_item32_t *));
self->num_items = num_items;
}
for (mp_uint_t item_index = 0; item_index < num_items; item_index++) {
mp_uint_t pulse_index = item_index * 2;
self->items[item_index].duration0 = mp_obj_get_int(pulses_ptr[pulse_index++]);
self->items[item_index].level0 = start++; // Note that start _could_ wrap.
if (pulse_index < pulses_length) {
self->items[item_index].duration1 = mp_obj_get_int(pulses_ptr[pulse_index]);
self->items[item_index].level1 = start++;
}
}
if (self->loop_en) {
bool loop_en;
check_esp_err(rmt_get_tx_loop_mode(self->channel_id, &loop_en));
if (loop_en) {
check_esp_err(rmt_set_tx_intr_en(self->channel_id, true));
check_esp_err(rmt_set_tx_loop_mode(self->channel_id, false));
}
check_esp_err(rmt_wait_tx_done(self->channel_id, portMAX_DELAY));
check_esp_err(rmt_set_tx_intr_en(self->channel_id, false));
}
check_esp_err(rmt_write_items(self->channel_id, self->items, num_items, false /* non-blocking */));
if (self->loop_en) {
check_esp_err(rmt_set_tx_loop_mode(self->channel_id, true));
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(esp32_rmt_write_pulses_obj, 2, esp32_rmt_write_pulses);
STATIC const mp_rom_map_elem_t esp32_rmt_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&esp32_rmt_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&esp32_rmt_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_source_freq), MP_ROM_PTR(&esp32_rmt_source_freq_obj) },
{ MP_ROM_QSTR(MP_QSTR_clock_div), MP_ROM_PTR(&esp32_rmt_clock_div_obj) },
{ MP_ROM_QSTR(MP_QSTR_wait_done), MP_ROM_PTR(&esp32_rmt_wait_done_obj) },
{ MP_ROM_QSTR(MP_QSTR_loop), MP_ROM_PTR(&esp32_rmt_loop_obj) },
{ MP_ROM_QSTR(MP_QSTR_write_pulses), MP_ROM_PTR(&esp32_rmt_write_pulses_obj) },
};
STATIC MP_DEFINE_CONST_DICT(esp32_rmt_locals_dict, esp32_rmt_locals_dict_table);
const mp_obj_type_t esp32_rmt_type = {
{ &mp_type_type },
.name = MP_QSTR_RMT,
.print = esp32_rmt_print,
.make_new = esp32_rmt_make_new,
.locals_dict = (mp_obj_dict_t *)&esp32_rmt_locals_dict,
};