Regarding SPI communication using DMA and manual SPI_CS operation

[pass3master]

We are performing SPI communication using DMA.

In this case, we manually set the GPIO to High/Low as SPI_CS, but (obviously) SPI_CS goes High before all of the SPI CLK is sent.

How can we manually return SPI_CS to its original state after all of the SPI CLK has been sent?
Should We use SPI_DMATransmitReceiveCplt?

[Andrew Neil]

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@pass3master wrote:

we manually set the GPIO to High/Low as SPI_CS, but (obviously) SPI_CS goes High before all of the SPI CLK is sent.

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No, that's not obvious at all - that's an error in your code!

When you choose to "manually" control CS, it's up to your code to ensure that it is asserted & released at the appropriate times.

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@pass3master wrote:

Should We use SPI_DMATransmitReceiveCplt?

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That would be the obvious way to do it - as the name suggests, that tells you when the transaction is complete!

[pass3master]

SPI_DMATransmitReceiveCplt is not called. Is there something we need to set? Do we need to set the ioc file?

[Andrew Neil]

Have you enabled the interrupt?

[pass3master]

By interrupt, do you mean a DMA interrupt?
The DMA1 stream2 global interrupt (the DMA stream we are using) is enabled.
The target SPI global interrupt is disabled.

[TDK]

You should set CS high in HAL_SPI_TxRxCpltCallback.

If that's not working, show the relevant code. Ensure DMA interrupts are enabled.

[Saket_Om]

Hello @pass3master 

1. You need to set the SPI global interrupt in the .ioc.
2. In your code call HAL_SPI_TransmitReceive_DMA() and then set CS high in the HAL_SPI_TxRxCpltCallback().