esp32: Bound PWM duty value. #6809
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Was about to send the same patch ! Commit message has been updated, and is now correct. For me it can be merged. |
|
Yes, it's an API inconsistency among ports... I deleted my git fork but I can repull if needed. |
|
I don't know if it required to do the actual merge ? If Yes, I would be glad you repull, because I have another ongoing pull request for ESP8266. |
|
Here it is: #6968 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
I had a potential out-of-boundary bug on an esp8266 device when setting the PWM duty value to control fan speed (negative value or >1023). On esp8266 the
machine.PWMbounds the duty value:micropython/ports/esp8266/esppwm.c
Lines 230 to 236 in 203e1d2
...so I didn't notice it. The PWM behaviour was normal, just bounded to 0 and 1023.
When I switched my code to an esp32, the fan behaviour was really strange, because the PWM duty value is only binary ANDed:
micropython/ports/esp32/machine_pwm.c
Line 270 in 4eaebc1
Negative values may be higher and bigger values lower. Combined with issue #5737 I thought first about a hardware problem...
This PR solves the problem and makes the esp32 PWM to have the same behaviour as esp8266/stm32 (AFAIK), by bounding the duty value between 0 and max PWM resolution. My previous buggy code works again :)