Fix LEDC resolution calculation on ESP32-C3/S2/S3 (#2794)

Co-authored-by: Oxan van Leeuwen <oxan@oxanvanleeuwen.nl>
Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
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rsumner 2021-11-24 16:22:51 -06:00 committed by GitHub
parent 4b1d73791d
commit 290da8df2d
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@ -16,6 +16,7 @@ namespace ledc {
static const char *const TAG = "ledc.output"; static const char *const TAG = "ledc.output";
#ifdef USE_ESP_IDF #ifdef USE_ESP_IDF
static const int MAX_RES_BITS = LEDC_TIMER_BIT_MAX - 1;
#if SOC_LEDC_SUPPORT_HS_MODE #if SOC_LEDC_SUPPORT_HS_MODE
// Only ESP32 has LEDC_HIGH_SPEED_MODE // Only ESP32 has LEDC_HIGH_SPEED_MODE
inline ledc_mode_t get_speed_mode(uint8_t channel) { return channel < 8 ? LEDC_HIGH_SPEED_MODE : LEDC_LOW_SPEED_MODE; } inline ledc_mode_t get_speed_mode(uint8_t channel) { return channel < 8 ? LEDC_HIGH_SPEED_MODE : LEDC_LOW_SPEED_MODE; }
@ -25,19 +26,26 @@ inline ledc_mode_t get_speed_mode(uint8_t channel) { return channel < 8 ? LEDC_H
// https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/api-reference/peripherals/ledc.html#functionality-overview // https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/api-reference/peripherals/ledc.html#functionality-overview
inline ledc_mode_t get_speed_mode(uint8_t) { return LEDC_LOW_SPEED_MODE; } inline ledc_mode_t get_speed_mode(uint8_t) { return LEDC_LOW_SPEED_MODE; }
#endif #endif
#else
static const int MAX_RES_BITS = 20;
#endif #endif
float ledc_max_frequency_for_bit_depth(uint8_t bit_depth) { return 80e6f / float(1 << bit_depth); } float ledc_max_frequency_for_bit_depth(uint8_t bit_depth) { return 80e6f / float(1 << bit_depth); }
float ledc_min_frequency_for_bit_depth(uint8_t bit_depth) {
const float max_div_num = ((1 << 20) - 1) / 256.0f; float ledc_min_frequency_for_bit_depth(uint8_t bit_depth, bool low_frequency) {
const float max_div_num = ((1 << MAX_RES_BITS) - 1) / (low_frequency ? 32.0f : 256.0f);
return 80e6f / (max_div_num * float(1 << bit_depth)); return 80e6f / (max_div_num * float(1 << bit_depth));
} }
optional<uint8_t> ledc_bit_depth_for_frequency(float frequency) { optional<uint8_t> ledc_bit_depth_for_frequency(float frequency) {
for (int i = 20; i >= 1; i--) { ESP_LOGD(TAG, "Calculating resolution bit-depth for frequency %f", frequency);
const float min_frequency = ledc_min_frequency_for_bit_depth(i); for (int i = MAX_RES_BITS; i >= 1; i--) {
const float min_frequency = ledc_min_frequency_for_bit_depth(i, (frequency < 100));
const float max_frequency = ledc_max_frequency_for_bit_depth(i); const float max_frequency = ledc_max_frequency_for_bit_depth(i);
if (min_frequency <= frequency && frequency <= max_frequency) if (min_frequency <= frequency && frequency <= max_frequency) {
ESP_LOGD(TAG, "Resolution calculated as %d", i);
return i; return i;
}
} }
return {}; return {};
} }
@ -80,6 +88,10 @@ void LEDCOutput::setup() {
auto chan_num = static_cast<ledc_channel_t>(channel_ % 8); auto chan_num = static_cast<ledc_channel_t>(channel_ % 8);
bit_depth_ = *ledc_bit_depth_for_frequency(frequency_); bit_depth_ = *ledc_bit_depth_for_frequency(frequency_);
if (bit_depth_ < 1) {
ESP_LOGW(TAG, "Frequency %f can't be achieved with any bit depth", frequency_);
this->status_set_warning();
}
ledc_timer_config_t timer_conf{}; ledc_timer_config_t timer_conf{};
timer_conf.speed_mode = speed_mode; timer_conf.speed_mode = speed_mode;