Files
zigbeelight/main/light_driver.c
2026-03-16 01:08:28 +01:00

83 lines
3.3 KiB
C

#include "light_driver.h"
#include <esp_zigbee_core.h>
#include "driver/ledc.h"
#include "esp_log.h"
#include "esp_err.h"
#include <stdbool.h>
#include <math.h>
static const char* TAG = "light_driver";
/* tweakable stuff */
static const uint8_t light_gpio = 2;
static const uint16_t light_pwm_freq = 65000;
static const ledc_timer_bit_t light_pwm_resolution = LEDC_TIMER_10_BIT;
static const double light_lowest_duty_pct = 0.05; // lowest duty percentage where the LEDs still light up nice
/* no need to tweak this stuff */
static const ledc_channel_t light_ledc_channel = LEDC_CHANNEL_0;
static const ledc_mode_t light_ledc_speed_mode = LEDC_LOW_SPEED_MODE;
static const uint32_t light_brightness_steps = (1 << light_pwm_resolution) - 1;
/* global vars */
static bool light_init_done = false;
static uint8_t light_current_level = 0;
static uint16_t gamma_lut[ZIGBEE_LIGHT_LEVELS + 1];
esp_err_t light_driver_set_level(const uint8_t level, const uint16_t transition_ms) {
if (!light_init_done) {
ESP_LOGW(TAG, "light driver not ready!");
return ESP_FAIL;
}
light_current_level = level;
const uint16_t duty = gamma_lut[light_current_level];
ESP_ERROR_CHECK(ledc_fade_stop(light_ledc_speed_mode, light_ledc_channel));
ESP_ERROR_CHECK(ledc_set_fade_with_time(light_ledc_speed_mode, light_ledc_channel, duty, transition_ms));
ESP_ERROR_CHECK(ledc_fade_start(light_ledc_speed_mode, light_ledc_channel, LEDC_FADE_NO_WAIT));
ESP_LOGI(TAG, "led set to %d, max is %d", duty, light_brightness_steps);
return ESP_OK;
}
esp_err_t light_driver_set_power(const bool power, const uint16_t transition_ms) {
return light_driver_set_level(power ? light_current_level : 0, transition_ms);
}
esp_err_t light_driver_init(const bool default_state) {
const ledc_timer_config_t ledc_timer = {
.speed_mode = light_ledc_speed_mode,
.duty_resolution = light_pwm_resolution,
.timer_num = LEDC_TIMER_2,
.freq_hz = light_pwm_freq,
.clk_cfg = LEDC_AUTO_CLK
};
const ledc_channel_config_t ledc_channel = {
.speed_mode = ledc_timer.speed_mode,
.channel = light_ledc_channel,
.timer_sel = ledc_timer.timer_num,
.intr_type = LEDC_INTR_DISABLE,
.gpio_num = light_gpio,
.duty = 0, // Set duty to 0%
.hpoint = 0
};
for (uint8_t i = 0; i <= ZIGBEE_LIGHT_LEVELS; i++) {
const double brightness_pct = (double)i / (double)ZIGBEE_LIGHT_LEVELS;
const double gamma_corrected = pow(brightness_pct, 2.2);
const double scaled = (double)light_brightness_steps * gamma_corrected * (1 - light_lowest_duty_pct);
gamma_lut[i] = (uint16_t)scaled + (uint16_t)((double)light_brightness_steps * light_lowest_duty_pct) + 1;
}
gamma_lut[0] = 0; // 0 is always completely off
if (gamma_lut[ZIGBEE_LIGHT_LEVELS] > light_brightness_steps) gamma_lut[ZIGBEE_LIGHT_LEVELS] = light_brightness_steps;
ESP_LOGI(TAG, "pre-computed brightness lookup table");
ESP_ERROR_CHECK(ledc_timer_config(&ledc_timer));
ESP_ERROR_CHECK(ledc_channel_config(&ledc_channel));
ESP_ERROR_CHECK(ledc_fade_func_install(0));
ESP_LOGI(TAG, "ledc driver initialized, f=%d Hz, %d step resolution", light_pwm_freq, light_brightness_steps);
light_init_done = true;
light_driver_set_power(default_state, 100);
return ESP_OK;
}