Random SPI data shifting at ~72kB/s throughput

[Musa]

Hello,

I am using nRF52 with ADS1292, and i am trying to sample at 8kHz with data throughput of 72kB/s, but some data is being randomly shifted giving me random spikes. This occurs on all available clock speeds to some degree. I am using Easy DMA. I am not getting any warnings or errors from the SPI driver as far as I can tell.

This issue does not occur at a lower data rate. Does this have something to do with overhead from the nRF SPIM drivers? I am also using I2C and other resources, but this also occurs with those additional resources disabled.

I'm trying to figure out what the limitation here is; is there a known limit on how many times you can call 'nrf_drv_spi_transfer' every second?

Thanks,

[MartinBL]

1. So in other words, you don't know if it shifts a certain number of bytes either to the left or right? It could be shifted e.g. just one bit both ways?
2. Is it possible that it is because of bad wiring? Have you remembered to connect both devices to common ground? With bad wires or grounding you can pick up noise that registers as bits. It would also behave quite random.