Get actual running duty from LedcDriver?

[hongquan]

The context:

I'm writing an application to control stepper motor and use esp_idf_hal::ledc::LedcDriver to generate PWM for that motor. The motor will be on / off depending on some condition (our application is to control peristaltic pump for hydroponic farm). I currently use LedcDriver::enable, LedcDriver::disable to turn on / off the motor. We also need to regularly report the motor status (on or off). Tried LedcDriver::get_duty() but it is not what I am looking for, because it returns the original-set duty cycle, no matter if the motor is on or off. I found that the esp_idf_sys::ledc_get_duty returns what we want, but LedcDriver doesn't have a wrapper method for this function yet.

Discussed

I have discussed with @Vollbrecht on Matrix, here is his opinion:

Personally i also don't find it appropriate to call the method that does this disable(). Disable is ambiguous here, as it could mean the timer or the output pin. And in what state the output itself is in disable is also ambiguous e.g high/low. What probably should be done:

deprecate the disable() method for ambiguity add wrappers around the ledc_timer_pause / ledc_timer_resume functions add convenient methods that set the duty to 0 or 100% maybe something like set_low, set_high or set_min_duty()/set_max_duty() ( this methods would update the state value and you would get the current correct duty value) adding just a second method that returns the "true" duty cycle in that case would only add more confusion. So that's why i think we should rework it.

So I bring this issue up here to get a final decision.