PWM conflict with FreeRTOS Thread example

[jonbas]

Hi,

I've created 3 PWM pulses via:

APP_PWM_INSTANCE(PWM1,2);                   // Create the instance "PWM1" using TIMER1.
APP_PWM_INSTANCE(PWM2,3);
APP_PWM_INSTANCE(PWM3,4);

    app_pwm_config_t pwm1_cfg = APP_PWM_DEFAULT_CONFIG_1CH(5000L, LED_R);
    app_pwm_config_t pwm2_cfg = APP_PWM_DEFAULT_CONFIG_1CH(5000L, LED_G);
    app_pwm_config_t pwm3_cfg = APP_PWM_DEFAULT_CONFIG_1CH(5000L, LED_B);

    /* Initialize and enable PWM. */
    err_code = app_pwm_init(&PWM1, &pwm1_cfg, pwm_ready_callback);
    APP_ERROR_CHECK(err_code);
    err_code = app_pwm_init(&PWM2, &pwm2_cfg, pwm_ready_callback);
    APP_ERROR_CHECK(err_code);
    err_code = app_pwm_init(&PWM3, &pwm3_cfg, pwm_ready_callback);
    APP_ERROR_CHECK(err_code);

    app_pwm_enable(&PWM1);
    app_pwm_enable(&PWM2);
    app_pwm_enable(&PWM3);

    
    while (app_pwm_channel_duty_set(&PWM1, 0, 0) == NRF_ERROR_BUSY);
    while (app_pwm_channel_duty_set(&PWM2, 0, 0) == NRF_ERROR_BUSY);
    while (app_pwm_channel_duty_set(&PWM3, 0, 100) == NRF_ERROR_BUSY);

Which works when I'm not starting Thread (from the examples/thread/freertos_coap_server example)

But when I start Thread (via the commands below), the last configured PWM is not working

    thread_coap_utils_led_timer_init();
    thread_coap_utils_provisioning_timer_init();
    thread_instance_init();
    thread_coap_init();
    thread_bsp_init();
    thread_coap_utils_light_changed_callback_set(light_changed);
    thread_initialized = true;

In this example, the BLUE led is configured last, which means I cannot change this PWM after calling thread_instance_init()

I've boiled the bug down to this function (in thread_utils.c):

error = otIp6SetEnabled(mp_ot_instance, true);

After executing this function, I see that the BLUE led disappears. Unfortunately, I cannot debug in further down due to this function being in a library.

Any advice/help?

Thanks,

Jonathan

[AndreasF]

Hi.

Which state are you in when you call otIp6SetEnabled?

Looking at the openThread stack it looks like the state could be the issue

Best regards,

Andreas

[jonbas]

the state is OT_ERROR_NONE

I tried with the old PWM driver (nrfx_pwm), and that works flawless.

[AndreasF]

Hi.

jonbas said:

the state is OT_ERROR_NONE

 Is that before or after you have called otIp6SetEnabled?

Which SDK is the driver working from, which SDK is the driver not working from?

Best regards,

Andreas

[jonbas]

I use this SDK: nRF5SDKforThreadandZigbeev300d310e71

The state is after the function has been called.

I tested with app_pwm.c and with nrfx_pwm.c. 

The problem is when using app_pwm.c, replace the functions with the one in nrfx_pwm.c, and the issue is gone.

[AndreasF]

Hi.

I'm a bit unsure why this relates to otIp6SetEnabled().

Could you share your project with me, so I can take a look at it?

Best regards,

Andreas

[jonbas]

The project is available here:

https://basalte-my.sharepoint.com/:u:/g/personal/jonathan_vervaeke_basalte_be/ERICxS3COrdMoiCGPNMwI_UBfRrOblLxIbVbDqRr_4AO4A?e=PQQsGO

This blinks an RGB led attached to R -> 1.10, G -> 1.14, B -> 1.11

The main code is in drivers/led/led.c

When running the example, only the R and G led works, the B led does not work.

I've created two defines which changes the order of initializing the PWM, which breaks the Green led instead of the Blue led:

#define LED_BLUE_BROKEN
//#define LED_GREEN_BROKEN

Another way of looking into this is by comment out the initialization of the thread device (in main.c).

(This leaded me to the otIp6SetEnabled() function.)

When you do this, all leds blink correctly!

    /*thread_instance_init();
    thread_coap_init();
    thread_bsp_init();
    thread_coap_utils_light_changed_callback_set(light_changed);
    thread_initialized = true;*/

Thanks for looking into this!