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micropython/ports/esp32/machine_pwm.c

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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016-2021 Damien P. George
* Copyright (c) 2018 Alan Dragomirecky
* Copyright (c) 2020 Antoine Aubert
* Copyright (c) 2021 Ihor Nehrutsa
*
* 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 <math.h>
#include "py/runtime.h"
#include "py/mphal.h"
#include "driver/ledc.h"
#include "esp_err.h"
#define PWM_DBG(...)
// #define PWM_DBG(...) mp_printf(&mp_plat_print, __VA_ARGS__); mp_printf(&mp_plat_print, "\n");
// Total number of channels
#define PWM_CHANNEL_MAX (LEDC_SPEED_MODE_MAX * LEDC_CHANNEL_MAX)
typedef struct _chan_t {
// Which channel has which GPIO pin assigned?
// (-1 if not assigned)
gpio_num_t pin;
// Which channel has which timer assigned?
// (-1 if not assigned)
int timer_idx;
} chan_t;
// List of PWM channels
STATIC chan_t chans[PWM_CHANNEL_MAX];
// channel_idx is an index (end-to-end sequential numbering) for all channels
// available on the chip and described in chans[]
#define CHANNEL_IDX(mode, channel) (mode * LEDC_CHANNEL_MAX + channel)
#define CHANNEL_IDX_TO_MODE(channel_idx) (channel_idx / LEDC_CHANNEL_MAX)
#define CHANNEL_IDX_TO_CHANNEL(channel_idx) (channel_idx % LEDC_CHANNEL_MAX)
// Total number of timers
#define PWM_TIMER_MAX (LEDC_SPEED_MODE_MAX * LEDC_TIMER_MAX)
// List of timer configs
STATIC ledc_timer_config_t timers[PWM_TIMER_MAX];
// timer_idx is an index (end-to-end sequential numbering) for all timers
// available on the chip and configured in timers[]
#define TIMER_IDX(mode, timer) (mode * LEDC_TIMER_MAX + timer)
#define TIMER_IDX_TO_MODE(timer_idx) (timer_idx / LEDC_TIMER_MAX)
#define TIMER_IDX_TO_TIMER(timer_idx) (timer_idx % LEDC_TIMER_MAX)
// Params for PWM operation
// 5khz is default frequency
#define PWM_FREQ (5000)
// 10-bit resolution (compatible with esp8266 PWM)
#define PWM_RES_10_BIT (LEDC_TIMER_10_BIT)
// Maximum duty value on 10-bit resolution
#define MAX_DUTY_U10 ((1 << PWM_RES_10_BIT) - 1)
// https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/ledc.html#supported-range-of-frequency-and-duty-resolutions
// duty() uses 10-bit resolution or less
// duty_u16() and duty_ns() use 16-bit resolution or less
// Possible highest resolution in device
#if (LEDC_TIMER_BIT_MAX - 1) < LEDC_TIMER_16_BIT
#define HIGHEST_PWM_RES (LEDC_TIMER_BIT_MAX - 1)
#else
#define HIGHEST_PWM_RES (LEDC_TIMER_16_BIT) // 20 bit for ESP32, but 16 bit is used
#endif
// Duty resolution of user interface in `duty_u16()` and `duty_u16` parameter in constructor/initializer
#define UI_RES_16_BIT (16)
// Maximum duty value on highest user interface resolution
#define UI_MAX_DUTY ((1 << UI_RES_16_BIT) - 1)
// How much to shift from the HIGHEST_PWM_RES duty resolution to the user interface duty resolution UI_RES_16_BIT
#define UI_RES_SHIFT (UI_RES_16_BIT - HIGHEST_PWM_RES) // 0 for ESP32, 2 for S2, S3, C3
#if SOC_LEDC_SUPPORT_REF_TICK
// If the PWM frequency is less than EMPIRIC_FREQ, then LEDC_REF_CLK_HZ(1 MHz) source is used, else LEDC_APB_CLK_HZ(80 MHz) source is used
#define EMPIRIC_FREQ (10) // Hz
#endif
// Config of timer upon which we run all PWM'ed GPIO pins
STATIC bool pwm_inited = false;
// MicroPython PWM object struct
typedef struct _machine_pwm_obj_t {
mp_obj_base_t base;
gpio_num_t pin;
bool active;
int mode;
int channel;
int timer;
int duty_x; // PWM_RES_10_BIT if duty(), HIGHEST_PWM_RES if duty_u16(), -HIGHEST_PWM_RES if duty_ns()
int duty_u10; // stored values from previous duty setters
int duty_u16; // - / -
int duty_ns; // - / -
} machine_pwm_obj_t;
STATIC bool is_timer_in_use(int current_channel_idx, int timer_idx);
STATIC void set_duty_u16(machine_pwm_obj_t *self, int duty);
STATIC void set_duty_u10(machine_pwm_obj_t *self, int duty);
STATIC void set_duty_ns(machine_pwm_obj_t *self, int ns);
STATIC void pwm_init(void) {
// Initial condition: no channels assigned
for (int i = 0; i < PWM_CHANNEL_MAX; ++i) {
chans[i].pin = -1;
chans[i].timer_idx = -1;
}
// Prepare all timers config
// Initial condition: no timers assigned
for (int i = 0; i < PWM_TIMER_MAX; ++i) {
timers[i].duty_resolution = HIGHEST_PWM_RES;
// unset timer is -1
timers[i].freq_hz = -1;
timers[i].speed_mode = TIMER_IDX_TO_MODE(i);
timers[i].timer_num = TIMER_IDX_TO_TIMER(i);
timers[i].clk_cfg = LEDC_AUTO_CLK; // will reinstall later according to the EMPIRIC_FREQ
}
}
// Deinit channel and timer if the timer is unused
STATIC void pwm_deinit(int channel_idx) {
// Valid channel?
if ((channel_idx >= 0) && (channel_idx < PWM_CHANNEL_MAX)) {
// Clean up timer if necessary
int timer_idx = chans[channel_idx].timer_idx;
if (timer_idx != -1) {
if (!is_timer_in_use(channel_idx, timer_idx)) {
check_esp_err(ledc_timer_rst(TIMER_IDX_TO_MODE(timer_idx), TIMER_IDX_TO_TIMER(timer_idx)));
// Flag it unused
timers[chans[channel_idx].timer_idx].freq_hz = -1;
}
}
int pin = chans[channel_idx].pin;
if (pin != -1) {
int mode = CHANNEL_IDX_TO_MODE(channel_idx);
int channel = CHANNEL_IDX_TO_CHANNEL(channel_idx);
// Mark it unused, and tell the hardware to stop routing
check_esp_err(ledc_stop(mode, channel, 0));
// Disable ledc signal for the pin
// gpio_matrix_out(pin, SIG_GPIO_OUT_IDX, false, false);
if (mode == LEDC_LOW_SPEED_MODE) {
gpio_matrix_out(pin, LEDC_LS_SIG_OUT0_IDX + channel, false, true);
} else {
#if LEDC_SPEED_MODE_MAX > 1
#if CONFIG_IDF_TARGET_ESP32
gpio_matrix_out(pin, LEDC_HS_SIG_OUT0_IDX + channel, false, true);
#else
#error Add supported CONFIG_IDF_TARGET_ESP32_xxx
#endif
#endif
}
}
chans[channel_idx].pin = -1;
chans[channel_idx].timer_idx = -1;
}
}
// This called from Ctrl-D soft reboot
void machine_pwm_deinit_all(void) {
if (pwm_inited) {
for (int channel_idx = 0; channel_idx < PWM_CHANNEL_MAX; ++channel_idx) {
pwm_deinit(channel_idx);
}
pwm_inited = false;
}
}
STATIC void configure_channel(machine_pwm_obj_t *self) {
ledc_channel_config_t cfg = {
.channel = self->channel,
.duty = (1 << (timers[TIMER_IDX(self->mode, self->timer)].duty_resolution)) / 2,
.gpio_num = self->pin,
.intr_type = LEDC_INTR_DISABLE,
.speed_mode = self->mode,
.timer_sel = self->timer,
};
if (ledc_channel_config(&cfg) != ESP_OK) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("PWM not supported on Pin(%d)"), self->pin);
}
}
STATIC void set_freq(machine_pwm_obj_t *self, unsigned int freq, ledc_timer_config_t *timer) {
if (freq != timer->freq_hz) {
// Find the highest bit resolution for the requested frequency
unsigned int i = LEDC_APB_CLK_HZ; // 80 MHz
#if SOC_LEDC_SUPPORT_REF_TICK
if (freq < EMPIRIC_FREQ) {
i = LEDC_REF_CLK_HZ; // 1 MHz
}
#endif
#if ESP_IDF_VERSION < ESP_IDF_VERSION_VAL(5, 0, 0)
// original code
i /= freq;
#else
// See https://github.com/espressif/esp-idf/issues/7722
int divider = (i + freq / 2) / freq; // rounded
if (divider == 0) {
divider = 1;
}
float f = (float)i / divider; // actual frequency
if (f <= 1.0) {
f = 1.0;
}
i = (unsigned int)roundf((float)i / f);
#endif
unsigned int res = 0;
for (; i > 1; i >>= 1) {
++res;
}
if (res == 0) {
res = 1;
} else if (res > HIGHEST_PWM_RES) {
// Limit resolution to HIGHEST_PWM_RES to match units of our duty
res = HIGHEST_PWM_RES;
}
// Configure the new resolution and frequency
timer->duty_resolution = res;
timer->freq_hz = freq;
timer->clk_cfg = LEDC_USE_APB_CLK;
#if SOC_LEDC_SUPPORT_REF_TICK
if (freq < EMPIRIC_FREQ) {
timer->clk_cfg = LEDC_USE_REF_TICK;
}
#endif
// Set frequency
esp_err_t err = ledc_timer_config(timer);
if (err != ESP_OK) {
if (err == ESP_FAIL) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("unreachable frequency %d"), freq);
} else {
check_esp_err(err);
}
}
// Reset the timer if low speed
if (self->mode == LEDC_LOW_SPEED_MODE) {
check_esp_err(ledc_timer_rst(self->mode, self->timer));
}
}
// Save the same duty cycle when frequency is changed
if (self->duty_x == HIGHEST_PWM_RES) {
set_duty_u16(self, self->duty_u16);
} else if (self->duty_x == PWM_RES_10_BIT) {
set_duty_u10(self, self->duty_u10);
} else if (self->duty_x == -HIGHEST_PWM_RES) {
set_duty_ns(self, self->duty_ns);
}
}
// Calculate the duty parameters based on an ns value
STATIC int ns_to_duty(machine_pwm_obj_t *self, int ns) {
ledc_timer_config_t timer = timers[TIMER_IDX(self->mode, self->timer)];
int64_t duty = ((int64_t)ns * UI_MAX_DUTY * timer.freq_hz + 500000000LL) / 1000000000LL;
if ((ns > 0) && (duty == 0)) {
duty = 1;
} else if (duty > UI_MAX_DUTY) {
duty = UI_MAX_DUTY;
}
return duty;
}
STATIC int duty_to_ns(machine_pwm_obj_t *self, int duty) {
ledc_timer_config_t timer = timers[TIMER_IDX(self->mode, self->timer)];
int64_t ns = ((int64_t)duty * 1000000000LL + (int64_t)timer.freq_hz * UI_MAX_DUTY / 2) / ((int64_t)timer.freq_hz * UI_MAX_DUTY);
return ns;
}
#define get_duty_raw(self) ledc_get_duty(self->mode, self->channel)
STATIC uint32_t get_duty_u16(machine_pwm_obj_t *self) {
int resolution = timers[TIMER_IDX(self->mode, self->timer)].duty_resolution;
int duty = ledc_get_duty(self->mode, self->channel);
if (resolution <= UI_RES_16_BIT) {
duty <<= (UI_RES_16_BIT - resolution);
} else {
duty >>= (resolution - UI_RES_16_BIT);
}
return duty;
}
STATIC uint32_t get_duty_u10(machine_pwm_obj_t *self) {
return get_duty_u16(self) >> 6; // Scale down from 16 bit to 10 bit resolution
}
STATIC uint32_t get_duty_ns(machine_pwm_obj_t *self) {
return duty_to_ns(self, get_duty_u16(self));
}
STATIC void set_duty_u16(machine_pwm_obj_t *self, int duty) {
if ((duty < 0) || (duty > UI_MAX_DUTY)) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("duty_u16 must be from 0 to %d"), UI_MAX_DUTY);
}
ledc_timer_config_t timer = timers[TIMER_IDX(self->mode, self->timer)];
int channel_duty;
if (timer.duty_resolution <= UI_RES_16_BIT) {
channel_duty = duty >> (UI_RES_16_BIT - timer.duty_resolution);
} else {
channel_duty = duty << (timer.duty_resolution - UI_RES_16_BIT);
}
int max_duty = (1 << timer.duty_resolution) - 1;
if (channel_duty < 0) {
channel_duty = 0;
} else if (channel_duty > max_duty) {
channel_duty = max_duty;
}
check_esp_err(ledc_set_duty(self->mode, self->channel, channel_duty));
check_esp_err(ledc_update_duty(self->mode, self->channel));
/*
// Bug: Sometimes duty is not set right now.
// Not a bug. It's a feature. The duty is applied at the beginning of the next signal period.
// Bug: It has been experimentally established that the duty is setted during 2 signal periods, but 1 period is expected.
// See https://github.com/espressif/esp-idf/issues/7288
if (duty != get_duty_u16(self)) {
PWM_DBG("set_duty_u16(%u), get_duty_u16():%u, channel_duty:%d, duty_resolution:%d, freq_hz:%d", duty, get_duty_u16(self), channel_duty, timer.duty_resolution, timer.freq_hz);
ets_delay_us(2 * 1000000 / timer.freq_hz);
if (duty != get_duty_u16(self)) {
PWM_DBG("set_duty_u16(%u), get_duty_u16():%u, channel_duty:%d, duty_resolution:%d, freq_hz:%d", duty, get_duty_u16(self), channel_duty, timer.duty_resolution, timer.freq_hz);
}
}
*/
self->duty_x = HIGHEST_PWM_RES;
self->duty_u16 = duty;
}
STATIC void set_duty_u10(machine_pwm_obj_t *self, int duty) {
if ((duty < 0) || (duty > MAX_DUTY_U10)) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("duty must be from 0 to %u"), MAX_DUTY_U10);
}
set_duty_u16(self, duty << (UI_RES_16_BIT - PWM_RES_10_BIT));
self->duty_x = PWM_RES_10_BIT;
self->duty_u10 = duty;
}
STATIC void set_duty_ns(machine_pwm_obj_t *self, int ns) {
if ((ns < 0) || (ns > duty_to_ns(self, UI_MAX_DUTY))) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("duty_ns must be from 0 to %d ns"), duty_to_ns(self, UI_MAX_DUTY));
}
set_duty_u16(self, ns_to_duty(self, ns));
self->duty_x = -HIGHEST_PWM_RES;
self->duty_ns = ns;
}
/******************************************************************************/
#define SAME_FREQ_ONLY (true)
#define SAME_FREQ_OR_FREE (false)
#define ANY_MODE (-1)
// Return timer_idx. Use TIMER_IDX_TO_MODE(timer_idx) and TIMER_IDX_TO_TIMER(timer_idx) to get mode and timer
STATIC int find_timer(unsigned int freq, bool same_freq_only, int mode) {
int free_timer_idx_found = -1;
// Find a free PWM Timer using the same freq
for (int timer_idx = 0; timer_idx < PWM_TIMER_MAX; ++timer_idx) {
if ((mode == ANY_MODE) || (mode == TIMER_IDX_TO_MODE(timer_idx))) {
if (timers[timer_idx].freq_hz == freq) {
// A timer already uses the same freq. Use it now.
return timer_idx;
}
if (!same_freq_only && (free_timer_idx_found == -1) && (timers[timer_idx].freq_hz == -1)) {
free_timer_idx_found = timer_idx;
// Continue to check if a channel with the same freq is in use.
}
}
}
return free_timer_idx_found;
}
// Return true if the timer is in use in addition to current channel
STATIC bool is_timer_in_use(int current_channel_idx, int timer_idx) {
for (int i = 0; i < PWM_CHANNEL_MAX; ++i) {
if ((i != current_channel_idx) && (chans[i].timer_idx == timer_idx)) {
return true;
}
}
return false;
}
// Find a free PWM channel, also spot if our pin is already mentioned.
// Return channel_idx. Use CHANNEL_IDX_TO_MODE(channel_idx) and CHANNEL_IDX_TO_CHANNEL(channel_idx) to get mode and channel
STATIC int find_channel(int pin, int mode) {
int avail_idx = -1;
int channel_idx;
for (channel_idx = 0; channel_idx < PWM_CHANNEL_MAX; ++channel_idx) {
if ((mode == ANY_MODE) || (mode == CHANNEL_IDX_TO_MODE(channel_idx))) {
if (chans[channel_idx].pin == pin) {
break;
}
if ((avail_idx == -1) && (chans[channel_idx].pin == -1)) {
avail_idx = channel_idx;
}
}
}
if (channel_idx >= PWM_CHANNEL_MAX) {
channel_idx = avail_idx;
}
return channel_idx;
}
/******************************************************************************/
// MicroPython bindings for PWM
STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "PWM(Pin(%u)", self->pin);
if (self->active) {
mp_printf(print, ", freq=%u", ledc_get_freq(self->mode, self->timer));
if (self->duty_x == PWM_RES_10_BIT) {
mp_printf(print, ", duty=%d", get_duty_u10(self));
} else if (self->duty_x == -HIGHEST_PWM_RES) {
mp_printf(print, ", duty_ns=%d", get_duty_ns(self));
} else {
mp_printf(print, ", duty_u16=%d", get_duty_u16(self));
}
int resolution = timers[TIMER_IDX(self->mode, self->timer)].duty_resolution;
mp_printf(print, ", resolution=%d", resolution);
mp_printf(print, ", (duty=%.2f%%, resolution=%.3f%%)", 100.0 * get_duty_raw(self) / (1 << resolution), 100.0 * 1 / (1 << resolution)); // percents
mp_printf(print, ", mode=%d, channel=%d, timer=%d", self->mode, self->channel, self->timer);
}
mp_printf(print, ")");
}
// This called from pwm.init() method
STATIC void mp_machine_pwm_init_helper(machine_pwm_obj_t *self,
size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_freq, ARG_duty, ARG_duty_u16, ARG_duty_ns };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_freq, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_u16, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_ns, 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);
int channel_idx = find_channel(self->pin, ANY_MODE);
if (channel_idx == -1) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("out of PWM channels:%d"), PWM_CHANNEL_MAX); // in all modes
}
int duty = args[ARG_duty].u_int;
int duty_u16 = args[ARG_duty_u16].u_int;
int duty_ns = args[ARG_duty_ns].u_int;
if (((duty != -1) && (duty_u16 != -1)) || ((duty != -1) && (duty_ns != -1)) || ((duty_u16 != -1) && (duty_ns != -1))) {
mp_raise_ValueError(MP_ERROR_TEXT("only one of parameters 'duty', 'duty_u16' or 'duty_ns' is allowed"));
}
int freq = args[ARG_freq].u_int;
// Check if freq wasn't passed as an argument
if (freq == -1) {
// Check if already set, otherwise use the default freq.
// It is possible in case:
// pwm = PWM(pin, freq=1000, duty=256)
// pwm = PWM(pin, duty=128)
if (chans[channel_idx].timer_idx != -1) {
freq = timers[chans[channel_idx].timer_idx].freq_hz;
}
if (freq <= 0) {
freq = PWM_FREQ;
}
}
if ((freq <= 0) || (freq > 40000000)) {
mp_raise_ValueError(MP_ERROR_TEXT("freqency must be from 1Hz to 40MHz"));
}
int timer_idx;
int current_timer_idx = chans[channel_idx].timer_idx;
bool current_in_use = is_timer_in_use(channel_idx, current_timer_idx);
if (current_in_use) {
timer_idx = find_timer(freq, SAME_FREQ_OR_FREE, CHANNEL_IDX_TO_MODE(channel_idx));
} else {
timer_idx = chans[channel_idx].timer_idx;
}
if (timer_idx == -1) {
timer_idx = find_timer(freq, SAME_FREQ_OR_FREE, ANY_MODE);
}
if (timer_idx == -1) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("out of PWM timers:%d"), PWM_TIMER_MAX); // in all modes
}
int mode = TIMER_IDX_TO_MODE(timer_idx);
if (CHANNEL_IDX_TO_MODE(channel_idx) != mode) {
// unregister old channel
chans[channel_idx].pin = -1;
chans[channel_idx].timer_idx = -1;
// find new channel
channel_idx = find_channel(self->pin, mode);
if (CHANNEL_IDX_TO_MODE(channel_idx) != mode) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("out of PWM channels:%d"), PWM_CHANNEL_MAX); // in current mode
}
}
self->mode = mode;
self->timer = TIMER_IDX_TO_TIMER(timer_idx);
self->channel = CHANNEL_IDX_TO_CHANNEL(channel_idx);
// New PWM assignment
if ((chans[channel_idx].pin == -1) || (chans[channel_idx].timer_idx != timer_idx)) {
configure_channel(self);
chans[channel_idx].pin = self->pin;
}
chans[channel_idx].timer_idx = timer_idx;
self->active = true;
// Set timer frequency
set_freq(self, freq, &timers[timer_idx]);
// Set duty cycle?
if (duty_u16 != -1) {
set_duty_u16(self, duty_u16);
} else if (duty_ns != -1) {
set_duty_ns(self, duty_ns);
} else if (duty != -1) {
set_duty_u10(self, duty);
} else if (self->duty_x == 0) {
set_duty_u10(self, (1 << PWM_RES_10_BIT) / 2); // 50%
}
}
// This called from PWM() constructor
STATIC mp_obj_t mp_machine_pwm_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, 2, true);
gpio_num_t pin_id = machine_pin_get_id(args[0]);
// create PWM object from the given pin
machine_pwm_obj_t *self = mp_obj_malloc(machine_pwm_obj_t, &machine_pwm_type);
self->pin = pin_id;
self->active = false;
self->mode = -1;
self->channel = -1;
self->timer = -1;
self->duty_x = 0;
// start the PWM subsystem if it's not already running
if (!pwm_inited) {
pwm_init();
pwm_inited = true;
}
// start the PWM running for this channel
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
mp_machine_pwm_init_helper(self, n_args - 1, args + 1, &kw_args);
return MP_OBJ_FROM_PTR(self);
}
// This called from pwm.deinit() method
STATIC void mp_machine_pwm_deinit(machine_pwm_obj_t *self) {
int channel_idx = CHANNEL_IDX(self->mode, self->channel);
pwm_deinit(channel_idx);
self->active = false;
self->mode = -1;
self->channel = -1;
self->timer = -1;
self->duty_x = 0;
}
// Set's and get's methods of PWM class
STATIC mp_obj_t mp_machine_pwm_freq_get(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(ledc_get_freq(self->mode, self->timer));
}
STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq) {
if ((freq <= 0) || (freq > 40000000)) {
mp_raise_ValueError(MP_ERROR_TEXT("freqency must be from 1Hz to 40MHz"));
}
if (freq == timers[TIMER_IDX(self->mode, self->timer)].freq_hz) {
return;
}
int current_timer_idx = chans[CHANNEL_IDX(self->mode, self->channel)].timer_idx;
bool current_in_use = is_timer_in_use(CHANNEL_IDX(self->mode, self->channel), current_timer_idx);
// Check if an already running timer with the same freq is running
int new_timer_idx = find_timer(freq, SAME_FREQ_ONLY, self->mode);
// If no existing timer was found, and the current one is in use, then find a new one
if ((new_timer_idx == -1) && current_in_use) {
// Have to find a new timer
new_timer_idx = find_timer(freq, SAME_FREQ_OR_FREE, self->mode);
if (new_timer_idx == -1) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("out of PWM timers:%d"), PWM_TIMER_MAX); // in current mode
}
}
if ((new_timer_idx != -1) && (new_timer_idx != current_timer_idx)) {
// Bind the channel to the new timer
chans[self->channel].timer_idx = new_timer_idx;
if (ledc_bind_channel_timer(self->mode, self->channel, TIMER_IDX_TO_TIMER(new_timer_idx)) != ESP_OK) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("failed to bind timer to channel"));
}
if (!current_in_use) {
// Free the old timer
check_esp_err(ledc_timer_rst(self->mode, self->timer));
// Flag it unused
timers[current_timer_idx].freq_hz = -1;
}
current_timer_idx = new_timer_idx;
}
self->mode = TIMER_IDX_TO_MODE(current_timer_idx);
self->timer = TIMER_IDX_TO_TIMER(current_timer_idx);
// Set the frequency
set_freq(self, freq, &timers[current_timer_idx]);
}
STATIC mp_obj_t mp_machine_pwm_duty_get(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(get_duty_u10(self));
}
STATIC void mp_machine_pwm_duty_set(machine_pwm_obj_t *self, mp_int_t duty) {
set_duty_u10(self, duty);
}
STATIC mp_obj_t mp_machine_pwm_duty_get_u16(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(get_duty_u16(self));
}
STATIC void mp_machine_pwm_duty_set_u16(machine_pwm_obj_t *self, mp_int_t duty_u16) {
set_duty_u16(self, duty_u16);
}
STATIC mp_obj_t mp_machine_pwm_duty_get_ns(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(get_duty_ns(self));
}
STATIC void mp_machine_pwm_duty_set_ns(machine_pwm_obj_t *self, mp_int_t duty_ns) {
set_duty_ns(self, duty_ns);
}
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