RE: Problem with PWM and Timer simultaneous with WS2812B leds

dhinojosac — Tue, 30 Jan 2018 14:09:06 GMT

Thanks Sigurd, My mystake was that I had wrongly initialized (I had not added it) the module nrf_drv_WS2812_init(pin) in which pwm was initialized. There was no error in compile.

void nrf_drv_WS2812_init(uint8_t pin)
{

nrf_gpio_cfg_output(pin);
nrf_gpio_pin_clear(pin);

uint32_t err_code;
nrf_drv_pwm_config_t const config0 =
{
    .output_pins =
    {
        pin, // channel 0
        NRF_DRV_PWM_PIN_NOT_USED, // channel 1
        NRF_DRV_PWM_PIN_NOT_USED, // channel 2
        NRF_DRV_PWM_PIN_NOT_USED  // channel 3
    },
    .irq_priority = APP_IRQ_PRIORITY_LOW,
    .base_clock   = NRF_PWM_CLK_16MHz,
    .count_mode   = NRF_PWM_MODE_UP,
    .top_value    = PERIOD_TICKS,
    .load_mode    = NRF_PWM_LOAD_COMMON,
    .step_mode    = NRF_PWM_STEP_AUTO
};

err_code = nrf_drv_pwm_init(&m_pwm0, &config0, NULL);  // handler is NULL
APP_ERROR_CHECK(err_code);

for(int i = 0; i < NRF_PWM_VALUES_LENGTH(m_seq_values); i++)
{
    m_seq_values[i] = ONE_HIGH_TICKS;
}
	
for(int i = 0; i < RESET_ZEROS_AT_START; i++)
{
m_seq_values[i] = 0x8000;
}

m_seq_values[NR_OF_PIXELS * 24 + RESET_ZEROS_AT_START] = 0x8000;

nrf_drv_pwm_simple_playback(&m_pwm0, &m_seq, 1, 0);
}

RE: Problem with PWM and Timer simultaneous with WS2812B leds

Sigurd — Mon, 29 Jan 2018 10:03:05 GMT

Hi,

If you convert 3735928559 to hex value, you get the code DEADBEEF. This is typically a assert from the SoftDevice. This could happen if you are using e.g a peripheral with restricted access(The SoftDevice need e.g. TIMER0), or if you are calling a SoftDevice function from a high interrupt priority.

Could you post the code for the nrf_drv_WS2812_show() function? If we look at line 286 in nrf_drv_pwm.c, we have this line:

ASSERT(p_cb->state != NRF_DRV_STATE_UNINITIALIZED);

This means that you are trying to start a nrf_drv_pwm_simple_playback(), but you have not initialized the driver with nrf_drv_pwm_init().