https://devzone.nordicsemi.com/f/nordic-q-a/24911/change-ppi-controlled-spi-messageHi, I am currently implementing an application which uses PPI to control SPI transaction when a HIGH-LOW transition is detected on a GPIO pin. I first set up the transaction using nrf_drv_spi_xfer with RAM TX and RX buffer, also with the NRF_DRV_SPI_FLAG_HOLD_XFERen-USTelligent Community 13Thu, 07 Sep 2017 13:54:10 GMThttps://devzone.nordicsemi.com/thread/98113?ContentTypeID=1Thu, 07 Sep 2017 13:54:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cd448c00-1a71-4404-90b1-366592f60ae5Petter Myhre<p>And yes you should use repeated transfer. Each transaction should still be triggered by PPI. See the Repeated transfers section <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v14.0.0/hardware_driver_spi_master.html?cp=4_0_0_2_12">here</a>.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/98112?ContentTypeID=1Thu, 07 Sep 2017 13:51:49 GMT137ad170-7792-4731-bb38-c0d22fbe4515:30801432-7450-45d7-8715-ec2ac202c3bdPetter Myhre<p>That I don&#39;t know. If you want to share a complete project that reproduces the behavior I can try to test it here.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/98111?ContentTypeID=1Wed, 06 Sep 2017 13:56:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:661a0875-64e3-4c4e-af7f-efcc5c1803b4Fan Jiaming<p>Also, do you have any idea why changing the buffer content in the SPI handler doesn&#39;t work?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/98110?ContentTypeID=1Wed, 06 Sep 2017 13:56:24 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6dfa007d-36b6-4a79-ba4b-e312987b18dbFan Jiaming<p>Oh, it didn&#39;t occur to me I could implement this function using that flag. Should I also include the repeated transfer flag, as I am not sure about what repeated transfer does? Will the transaction keeps going on without PPI triggering a new task until you stop the transaction explicitly in the SPI handler?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/98114?ContentTypeID=1Wed, 06 Sep 2017 12:50:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fdec89c0-71e9-4774-a1f2-3849f91bff2fPetter Myhre<p>Sounds like you want to use repeated transfers with the NRF_DRV_SPI_FLAG_TX_POSTINC flag. Have you looked into that?</p><div style="clear:both;"></div>