NRF52 Calculation Method Between Rising Edges

[Glory]

HI.

I'm developing a nRF52 custom board.

I use a Crypto chip, and I have to calculate and store the count value between the Rising Edges.

How should I do it?

Please reply.

[Sigurd]

Hi,

Take a look at this post.

This might also be useful:pin_rise_count_ppi_gpiote_timers.zip

[Glory]

Using GPIOTE, can I set two pins to detect the Rising edge and start and end with PPI?

[Sigurd]

Yes, you have 8 GPIOTE channels, so that should not be an issue. Also note that PPI has a fork mechanism, so one event can trigger a second task.

[Glory]

After checking the code you attached, is it correct to check the Rising edge to Rising edge count with timer_handler_read?

[Sigurd]

For every transition from low to high, the counter is incremented, and can be read in timer_handler_read().

You might however need to change the argument in GPIOTE_CONFIG_IN_SENSE_LOTOHI() from false to true.

nrf_drv_gpiote_in_config_t in_config = GPIOTE_CONFIG_IN_SENSE_LOTOHI(true);

[Glory]

Oh...! 
There are a lot of things I don't know.

Thank you for helping me. I'll test the part you've mentioned after I've corrected it.

[Glory]

Handler does not work after timers_init.
timer_cfg.mode = NRF_TIMER_MODE_TIMER
timer_cfg.mode = NRF_TIMER_MODE_LOW_POWER_COUNTER

Is it correct to use these two functions together?

[Sigurd]

Glory said:

Is it correct to use these two functions together?

No, not for the same timer instance.

I made some adjustment to the example, e.g. added Segger RTT logging. It will count the number of low to high pulses for the duration of 10sec(COUNT_READ_INTERVAL), print the number, then it will restart counting from 0. I tested this with SDK 15.3:

Attachment: gpiote_timer_ppi.zip