← index #6945Issue #3631
Related · high · value 4.875
QUERY · ISSUE

ESP8266: PWM glitches when doing DHT measure

openby EddieParisopened 2021-02-21updated 2022-03-30
port-esp8266

When using a PWM channel in parallel of a DHT measure, there can be some glitches on the PWM channel at the measure time. This is because the DHT drivers locks interrupts for accurate protocol timing handling, and the PWM driver relies on these interrupts.

CANDIDATE · ISSUE

ESP8266 : PWM glitches from full pwm to any value (only if 1 channel active)

closedby EddieParisopened 2018-02-22updated 2018-03-05

The PWM at full value is not considered as an "active" channel so if no other channel is used the timer used to mange pwm is not started. So when another duty value is set the pwm timer restarts and there is a visible glitch when driving leds.

Edit: Root cause is obvious but solution is not. I have to do more tests and measures.

Keyboard

j / / n
next pair
k / / p
previous pair
1 / / h
show query pane
2 / / l
show candidate pane
c
copy suggested comment
r
toggle reasoning
g i
go to index
?
show this help
esc
close overlays

press ? or esc to close

copied