nRF52840 SPIM Easy DMA buffer >255bytes

RE: nRF52840 SPIM Easy DMA buffer >255bytes

tealtech — Thu, 12 Sep 2019 19:22:21 GMT

Thanks Einar. I removed the legacy drivers and libraries and updated the calls and it all works perfectly.

RE: nRF52840 SPIM Easy DMA buffer >255bytes

Einar Thorsrud — Thu, 12 Sep 2019 13:28:34 GMT

There are no examples that use nrfx directly. You can do it, but then you should remember to remove all configurations for the legacy driver in your projects sdk_config.h. Another alternative, which may be easier, is to just modify the nrf_drv_spi.c/.h files to use size_t. As you can see from the nrf_drv_spi implementation it essentially just calls the nrfx drivers, so changing all the length parameters from uint8_t to size_t should be enough.

RE: nRF52840 SPIM Easy DMA buffer >255bytes

tealtech — Thu, 12 Sep 2019 12:01:01 GMT

I've started out with the SPI library example, which still utilizes the old nrf libraries. Are there any newer examples which use only the nrfx spim drivers?

RE: nRF52840 SPIM Easy DMA buffer >255bytes

Einar Thorsrud — Thu, 12 Sep 2019 10:45:49 GMT

Hi,

The driver nrf_drv* use uint8_t for the length field for historic reasons (nRF52832). As @turboj wrote, this limitation is not present in nrfx, so you can work around this by using the nrfx_spim driver directly.

RE: nRF52840 SPIM Easy DMA buffer >255bytes

Turbo J — Wed, 11 Sep 2019 18:01:23 GMT

Which one of the various functions in the SDK do you use?

The structure from nrfx_spim.h uses size_t for transfer sizes and should not trigger compiler warnings.