PWM not working after upgrade to nrf Connect SDK 1.9.1

[csteaderman]

Since upgrading to nrf Connect SDK 1.9.1, I no longer have PWM output. No errors returned when calling pwm_pin_set_usec, yet no output.

I tried upgrading to the latest nrf Connect SDK (2.2.0), thinking that perhaps a bug was fixed, but the number of changes (include paths, etc) was too daunting.

[Sigurd Hellesvik]

Hi,

Can you post the part of your code where you use pwm_pin_set_usec()?

Regards,
Sigurd Hellesvik

[csteaderman]

#define AFE_CLOCK_NODE  DT_ALIAS(afe_clock)

#if DT_NODE_HAS_STATUS(AFE_CLOCK_NODE, okay)

#ifndef DT_PWMS_LABEL

#define AFE_CLOCK_LABEL DT_NODELABEL(AFE_CLOCK_NODE)

#else

#define AFE_CLOCK_LABEL DT_PWMS_LABEL(AFE_CLOCK_NODE)

#endif

#define AFE_CLOCK_CHANNEL   DT_PWMS_CHANNEL(AFE_CLOCK_NODE)

#define AFE_CLOCK_FLAGS DT_PWMS_FLAGS(AFE_CLOCK_NODE)

#else

#error "Unsupported board: afe-clock devicetree alias is not defined"

#define AFE_CLOCK_LABEL ""

#define AFE_CLOCK_CHANNEL   0

#define AFE_CLOCK_FLAGS 0

#endif

 

    int ret = 0;

    _AfeClock_dev = device_get_binding(AFE_CLOCK_LABEL);

    if (!_AfeClock_dev) {

        Z_LOG(LOG_LEVEL_ERR, "Error: didn't find %s device.", AFE_CLOCK_LABEL);

        ret |= 0x1;

    }

 

    ret = pwm_pin_set_usec(AfeClock_dev, AFE_CLOCK_CHANNEL,

                   PWM_USEC(period), PWM_USEC(width), AFE_CLOCK_FLAGS);

    if (ret) {

        Z_LOG(LOG_LEVEL_ERR, "Error %d: failed to set pulse width.", ret);

    }

[Sigurd Hellesvik]

Then I have another suggestion that you can try to debug:

Use Debugging for both v1.6.0 and v1.9.1.
Inspect the PWM peripheral in the debugging interface as such:

Do you see any difference here between the versions?

Regards,
Sigurd Hellesvik

[csteaderman]

I do not have my hardware with me today. I will get back to you tomorrow with results. Thanks for the suggestion.

[csteaderman]

1.6.1:

1.9.1:

Best I can tell, they are the same.

[csteaderman]

I was able to complete the upgrade to nrf Connect SDK 2.2.0, but the problem with PWM still exists.

[csteaderman]

I'm beginning to suspect that this is a devicetree configuration issue. Some of the macros that worked with 1.6.1 don't seem to work with 1.9.1 (or 2.2.0). Also, I am seeing deprecation warnings for I2C which makes me wonder if I should be refactoring my device tree and source code to match an updated implementation model? Unfortunately, I haven't had much luck finding good examples for defining PWM, SPI, and I2C peripherals in device tree and subsequently using them in my application. I am getting the following warning, but no description about the appriopriate alternate method for defining the actual pin assignment for the PWM signal.

'ch0-pin' is marked as deprecated in 'properties:' in C:/Nordic/v2.2.0/zephyr/dts/bindings\pwm\nordic,nrf-pwm.yaml for node /soc/pwm@4001c000.

[Sigurd Hellesvik]

Hi,

I am Out of Office today and tomorrow, but I will continue to look into this on Wednesday.

Regards,
Sigurd Hellesvik

[Sigurd Hellesvik]

Hi,

csteaderman said:

I am getting the following warning, but no description about the appriopriate alternate method for defining the actual pin assignment for the PWM signal.

'ch0-pin' is marked as deprecated in 'properties:' in C:/Nordic/v2.2.0/zephyr/dts/bindings\pwm\nordic,nrf-pwm.yaml for node /soc/pwm@4001c000.

See https://github.com/nrfconnect/sdk-nrf/blob/v2.2.0/samples/bluetooth/mesh/light_ctrl/boards/nrf5340dk_nrf5340_cpuapp_ns.overlay  for an example of a pwm overlay file.

csteaderman said:

Best I can tell, they are the same.

Oh well, it was worth a shot.

csteaderman said:

When I probe the GPIO line that is supposed to have the PWM signal on it, it is at 0V.

Which instrument did you use for probing? (oscilloscope/logic analyzer)?

Regards,
Sigurd Hellesvik

[csteaderman]

DMM.

[csteaderman]

Any more insights on how I should get PWM working on my custom PCBA?

[Sigurd Hellesvik]

Hi,

Sorry, this ticket was lost in the system.

Reading through it again now, I saw that I asked:

Sigurd Hellesvik said:

Can you try the zephyr fade_led sample on your board, to see if it behaves in the same way or not?

And you answered:

csteaderman said:

Not easily. My development is beyond using dev boards, and I am running on a custom PCBA now. When I probe the GPIO line that is supposed to have the PWM signal on it, it is at 0V.

Why can you not do it easily?

Would it not be using DTS to change the pins in the fade_led_sample and then probe the lines during the sample?

Regards,
Sigurd Hellesvik