nRF52832 use PPI to control an output pin GPIOTE

RE: nRF52832 use PPI to control an output pin GPIOTE

Philip — Mon, 03 Feb 2020 15:04:19 GMT

Hi Håkon,

That worked! Thanks.

Getting a 10mS On pulse now at 32Hz.

Phil

RE: nRF52832 use PPI to control an output pin GPIOTE

Håkon Alseth — Mon, 03 Feb 2020 14:59:54 GMT

Hi Phil,

[quote user="philipm"]If I do toggle the pin does toggle ok.[/quote]

This is good. The "logic underneath" works as it should

[quote user="philipm"]nrf_drv_gpiote_out_set(MI_EN);[/quote]

Could you try to call "nrf_drv_gpiote_set_task_trigger" instead?

Kind regards,

Håkon

RE: nRF52832 use PPI to control an output pin GPIOTE

Philip — Mon, 03 Feb 2020 14:46:19 GMT

Yes I set it high along with reseting the timers 32 times a second (see second code section).

//Set the output high
nrf_drv_gpiote_out_set(MI_EN);

If I do toggle the pin does toggle ok.

Phil

RE: nRF52832 use PPI to control an output pin GPIOTE

Håkon Alseth — Mon, 03 Feb 2020 14:35:32 GMT

Hi,

[quote user=""]The output is always off. If I set the task type to GPIOTE TASK_HIGH then the output is always on.[/quote]

If you configure the GPIOTE output to TASK_HIGH, then the transaction is from low-to-high on the event (configured via PPI):

/**@brief Macro for configuring a pin to use the GPIO OUT TASK to change the state from low to high.
 * @details The task will set the pin. Therefore, the pin is cleared initially.  */
#define NRFX_GPIOTE_CONFIG_OUT_TASK_HIGH            \
    {                                               \
        .init_state = NRF_GPIOTE_INITIAL_VALUE_LOW, \
        .task_pin   = true,                         \
        .action     = NRF_GPIOTE_POLARITY_LOTOHI,   \
    }

And the other way around when you configure with TASK_LOW, ie event will set the pin low:

/**@brief Macro for configuring a pin to use the GPIO OUT TASK to change the state from high to low.
 * @details The task will clear the pin. Therefore, the pin is set initially.  */
#define NRFX_GPIOTE_CONFIG_OUT_TASK_LOW              \
    {                                                \
        .init_state = NRF_GPIOTE_INITIAL_VALUE_HIGH, \
        .task_pin   = true,                          \
        .action     = NRF_GPIOTE_POLARITY_HITOLO,    \
    }

Are you toggling the pin somewhere else in your program? If not, it will only occur once, and be kept in that state for the rest of the runtime.

You could try to set "NRFX_GPIOTE_CONFIG_OUT_TASK_TOGGLE" to see if the pin itself toggles? just to see if the logic behind works as it should.

Kind regards,

Håkon