nrf52832 SDK13 PWM cant change duty cycle at first period

[jacksong]

hello ,everyone

I was confused by a PWM problem for a long time , on nrf52832 SDK13 ,i wanna change the PWM duty cycle every period ,but now i find can not change it at first period but is correct operate at subsequent period

the waveform shows that the second period is same with the first period , the third one and consecutive is invert channel 0 and channel 1 correctly

appendix the descriptive picture .

appendix the code of pwm handler

is a bug for the pwm driver ?

thanks for your attention

[Sigurd]

Hi,

Could you explain this some more ?

You have 3 PWM channels. Is the pwm signal correct on any of these channels ?

i wanna change the PWM duty cycle every period

What do you mean by this? You want to continuously change the duty cycle[%] to a different value after each period ? and for all channels ? Should this change be the same for all the channels ?

How should the PWM signal look like?

[jacksong]

hi, i want to generate a Periodically changing PWM waveform : the duty cycle has 2 value : 40% and 0%,channel0 is the opposite of channel1,channel2 is same of channel 1; duty cycle will switch value at every period finish. from the picture,you can see period 3,period 4...is change correctly ,but period 2 wrong looks like PWM can not change duty cycle(change RAM in pwm_handler) at first period finish，but the rest of period is change as expected

[Sigurd]

Could you post some more code on how this is configured and initialized? I.e. how does thenrf_drv_pwm_config_t looks like ? how does the call to nrf_drv_pwm_simple_playback() look like ?