PWM PHASE 120 degrees

RE: PWM PHASE 120 degrees

Sigurd — Fri, 11 Sep 2020 15:07:46 GMT

Hi,

I have not worked with BLDC before, but you could try to create a update function that changes the seq_values

RE: PWM PHASE 120 degrees

NikTheNordicUser — Wed, 09 Sep 2020 19:29:05 GMT

YES! thank you very much for your help, the scope for this is i need to move a bldc also is there some advice you can give me with regards to how i should attempt to go about with the 6 step commutation sequences of a bldc 3 phase bridge

RE: PWM PHASE 120 degrees

Sigurd — Tue, 08 Sep 2020 21:10:18 GMT

So with 120 degrees, you are trying to generate the signal shown here?

    nrf_drv_pwm_config_t const config0 =
    {
        .output_pins =
        {
            BSP_LED_0 | NRF_DRV_PWM_PIN_INVERTED, // channel 0
            BSP_LED_1 | NRF_DRV_PWM_PIN_INVERTED, // channel 1
            NRF_DRV_PWM_PIN_NOT_USED, // channel 2
            NRF_DRV_PWM_PIN_NOT_USED  // channel 3
        },
        .irq_priority = APP_IRQ_PRIORITY_LOWEST,
        .base_clock   = NRF_PWM_CLK_125kHz,
        .count_mode   = NRF_PWM_MODE_UP,
        .top_value    = 15625,
        .load_mode    = NRF_PWM_LOAD_INDIVIDUAL,
        .step_mode    = NRF_PWM_STEP_AUTO
    };
    APP_ERROR_CHECK(nrf_drv_pwm_init(&m_pwm0, &config0, NULL));

    // This array cannot be allocated on stack (hence "static") and it must
    // be in RAM (hence no "const", though its content is not changed).
    static nrf_pwm_values_individual_t /*const*/ seq_values[] =
    {
        { 0x8000,      0,      0,      0 },
        {      0, 0x8000,      0,      0 },
        {      0,      0,      0,      0 }
    };
    nrf_pwm_sequence_t const seq =
    {
        .values.p_individual = seq_values,
        .length              = NRF_PWM_VALUES_LENGTH(seq_values),
        .repeats             = 0,
        .end_delay           = 0
    };

    (void)nrf_drv_pwm_simple_playback(&m_pwm0, &seq, 1, NRF_DRV_PWM_FLAG_LOOP);

RE: PWM PHASE 120 degrees

NikTheNordicUser — Tue, 08 Sep 2020 11:44:58 GMT

Hi i have looked into that already but i was unable to move the phase more than 90 degrees

RE: PWM PHASE 120 degrees

Sigurd — Tue, 08 Sep 2020 11:16:12 GMT

Hi,

Documentation for the PWM driver can be found here.

Documentation for the PWM peripheral can be found here.