Making MCPWM easier to use (IDFGH-15230)

[Dhsjkd2]

Is your feature request related to a problem?

Compared to the old API, the MCPWM is just super confusing to use. I understand that ESP-IDF is developed for professionals, but some more examples of controlling motors from the MCPWM without abstractions like the "bdc_motor" component would be really helpful to actually be able to tailor the API to my own needs as the examples are way too generic as there are many other control schemes for H-bridge motor drivers.

Describe the solution you'd like.

No response

Describe alternatives you've considered.

No response

Additional context.

No response

[Kainarx]

Hi @Dhsjkd2
What specific function of the H-bridge driver do you actually want? Can it be achieved by adding functionality to the bdc_motor component?

[Dhsjkd2]

Hi, thanks for the fast response. I want to control a full h bridge with a single pwm signal. I feel like the new API is just too bloated for simple actions like changing the duty cycle and pwm frequency and there hasn't been a very specific guide. I feel like the bdc_motor component isn't very necessary and can just be done by making the new API similar to the old one with wrapper functions like mcpwm_set_duty().

[suda-morris]

MCPWM is a complex peripheral: the timer, comparator, and waveform generator in it are relatively independent modules, and the user can freely combine them, so the driver cannot assume that timer A must be combined with comparator M to implement a simple mcpwm_set_duty function.

However, in some real application scenarios, we can make some assumptions and simplifications to provide functions similar to mcpwm_set_duty, which is also the meaning of the birth of bdc_motor components.

In the future, there will be more components, which are based on MCPWM drivers and serve specific application scenarios.

changing the duty cycle and pwm frequency and there hasn't been a very specific guide

yes, this is a thing that we SHOULD improve in our programming guide.

[Dhsjkd2]

Hi! I think you have changed my mind a bit. You are definitely right - assuming that everyone will have a standardised use is very selfish of me. I would really appreciate if a more comprehensive guide is released via the docs as I am in need of it right now. As much as adding future components would be useful, I feel like I wouldn't like to use them and I would still prefer to use the "raw" IDF functions as it means there may be more bloat.

[suda-morris]

Hi @Dhsjkd2
Besides the examples, I hope you're also aware of the code that we used for testing. They're also using the "raw" IDF functions without extra dependency. For example, if you want to generate a simple PWM, I suggest you to read this code

esp-idf/components/esp_driver_mcpwm/test_apps/mcpwm/main/test_mcpwm_gen.c

Line 505 in aaebc37

TEST_CASE("mcpwm_generator_action_on_compare_event", "[mcpwm]")

with the waveform showcase demonstrated in https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/mcpwm.html#generator-configurations-for-classical-pwm-waveforms

[Dhsjkd2]

Hi, I have seen that code sample before but I think that most examples are very different from what I need and that they don't explain things very clearly as to the comparator events, etc. I guess the best thing I really want to see is a more detailed documentation on setting the signal frequency via the ticks and resolution and how to use the comparator.