Strange ledc_start_fade behaviour (more time than request) (IDFGH-14293)

[StefanoTesla]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

running this code:

ledc_channel_t ledcChannel = static_cast<ledc_channel_t>(0); esp_err_t fade_in_status = ledc_set_fade_with_time(LEDC_LOW_SPEED_MODE, ledcChannel, dutyValue, time); if (fade_in_status == ESP_OK){ ledc_fade_start(LEDC_LOW_SPEED_MODE, ledcChannel, LEDC_FADE_NO_WAIT);

I got a strange behaviour, for example if I pass 5000 in the time, esp32 took approx 9 seconds to make the fade, If I use something like 2000 it works like a sharm...

I got an esp32-d v3.0 espressif version 6.9.0

of course at the beginning I run ledc_fade_func_install(0);

[songruo]

Hi @StefanoTesla, our ledc_set_fade_with_time API does have the possibility of an inaccurate fade time, up to 50%, due to the the rounding of the scale/cycle parameters calculation internally (as a single linear fade). If you want a very accurate timing, you need to do some calculation by yourself to split the entire fade into multiple linear fades to avoid the rounding error.