How to use GPOE20(nrf54l15 P1.10) to configure DPPI on ncs3.1.1 version

[john.liu]

Hi:

use nrf54l15 and ncs v3.1.1.

The CS-PIN remained low during measurement.

I am unable to control CS PIN through DPPI.

Here is the source code：

ppi_spi.zip

[Vidar Berg]

Hello,

I don't immediately see what is wrong with the CS handling in your code, but is there a reason for not letting the SPI peripheral control the CS signal as I did in my sample app here: https://github.com/vidarbe/ncs-samples/tree/add_dppi_version/sensor_hub_with_dppi_lm20?

Best regards,

Vidar

EDIT: a coworker pointed out that the GPIOTE task config has the polarity set to NRF_GPIOTE_POLARITY_NONE. This should be sett to NRF_GPIOTE_POLARITY_TOGGLE if you want the signal to be asserted and de-asserted by a single event.

[john.liu]

Hi:
Thanks for your help!

After changing NRF_GPOTE-POLARITY_TOGGLE to CS, there is a level change, but the waveform is incorrect. The frequency of CLK is sometimes 6.67MHz and sometimes 10MHz.

It's strange that there was a pull up in the middle of the CS pin.

[john.liu]

The tested board is NRF54L15DK.

[Vidar Berg]

It seems like the logic analyser is not able to capture the signal correctly. Perhaps the sampling rate is not sufficient? For testing purposes, I suggest you lower the SPIM frequency below 1MHz to see if this improves the clock signal.