Does it have any API for notify when SPI burst read and write finished

RE: Does it have any API for notify when SPI burst read and write finished

yithwe — Thu, 09 May 2024 07:10:18 GMT

Hi Kenneth

Thanks for your suggestion, for our application we need to know EDMA finished it or not and need to know cs pin status to decide to go next step or for next data transceive start.

Best Regards

Tina

RE: Does it have any API for notify when SPI burst read and write finished

Kenneth — Wed, 08 May 2024 08:02:38 GMT

You should be able to search through the nRF Connect SDK repositories or documentation for use of spi_transceive_cb() if you want.

Normally though, I expect it is more common to place all the spi transcations you want to perform in a separate thread, and then each of the spi_transceive_dt() will be synchrounous transfer, thereby the spi_transceive_dt() will not return until the transfer is complete. This is slightly more easy to implement than having to wait for the callback for each transfer. Other threads can run while spi_transceive_dt() is executed.

Current consumption is the same for the two approaches.

Kenneth

RE: Does it have any API for notify when SPI burst read and write finished

yithwe — Wed, 08 May 2024 01:57:37 GMT

Hi Kenneth

Does it have any sample code for API spi_transceive_cb?can we use spi_transceive_cb to instead spi_transceive_dt?I need to know more detail about how to use call back function, Thanks.

Best Regards

Tina

RE: Does it have any API for notify when SPI burst read and write finished

Kenneth — Tue, 07 May 2024 16:24:30 GMT

Hello,

Yes, Zephyr can provide a callback mechanism for notifying when SPI read/write operations are finished. The callback function is specified when calling the spi_transceive_cb function. This function reads/writes the specified amount of data from the SPI driver and triggers the callback upon completion.

In this callback, you can implement the logic that should be executed when the SPI operation is finished. For more details, you can refer to the Zephyr documentation on the SPI interface:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/hardware/peripherals/spi.html#c.spi_transceive_cb

In the devicetree make sure to use the "nordic, nrf-spim" node to ensure that you use EasyDMA, ref:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/build/dts/api/bindings/spi/nordic%2Cnrf-spim.html#dtbinding-nordic-nrf-spim

If you use "nordic, nrf-spi" it may not be using EasyDMA.

For uart make sure to use "nordic, nrf-uarte" node to ensure that you use EasyDMA,, ref:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/build/dts/api/bindings/serial/nordic%2Cnrf-uarte.html#dtbinding-nordic-nrf-uarte

If you use "nordic, nrf-uart" it may not be using EasyDMA.

Kenneth