MicroPython Forum (Archive)

I can confirm that there is indeed a problem, at my board with all pins for frequencies below 700 Hz. I'll raise an issue.

Finally, I did a test. On the ESP32, THE PWM worked well when freq=611, but the PWM did not output when freq=610. Although I can only return 1.17 with 8 PWM pins, at least I know where the problem is. I look forward to a new firmware to solve my problem as soon as possible. Thank you very much for your kind and meticulous help.

esp32-20220117-v1.18.bin

When the PWM frequency is changed, the frequency after the change can be seen by using freq (), but the frequency displayed on the oscilloscope does not change

I made a PR which fixes the low frequency issue: https://github.com/micropython/micropython/pull/8200
Once the PR is merged, you can use the daily builds.
Id does not change the behavior, that small frequency changes do not affect the output frequency. That is related to the ESP32-idf library, but I also consider it unexpected.

Roberthh wrote: ↑

Sun Jan 23, 2022 1:03 pm

I made a PR which fixes the low frequency issue: https://github.com/micropython/micropython/pull/8200
Once the PR is merged, you can use the daily builds.
Id does not change the behavior, that small frequency changes do not affect the output frequency. That is related to the ESP32-idf library, but I also consider it unexpected.

I used the latest firmware (ESP32-20220127-unstable v1.18-42-g30b6CE86b.bin) and tested PWM. Still, FREq =700 works and FREq =50 does not. And I found a strange phenomenon, when I do PWM output to Pin(23), Pin(26) actually has PWM output at the same time.

The PR with the fix is not yet released by the maintainer. That takes usually a while.

And I found a strange phenomenon, when I do PWM output to Pin(23), Pin(26) actually has PWM output at the same time.

For the revised build I do not see such an effect.

Does anyone have a link for the mpremote tool mentioned in Damien's post? I'd like to learn about it but I couldn't find it by googling.

2nd hit in Google:
https://pypi.org/project/mpremote/
Then you need to look around that site to see how to install it. I think it is:

I tried pip install mpremote on a rpi host but it reckons no matching distribution available. Do I need some sort of special linux PC or something?

mpremote is OS independent but it requires pyserial which is a little more picky...maybe first try 'pip install pyserial' and see if that works?