nRF51822 spi master transfer uncertain delay between bytes

RE: nRF51822 spi master transfer uncertain delay between bytes

Kenneth — Mon, 02 May 2016 12:26:10 GMT

Have you used the spi example from the latest nRF5 SDK v11? See \examples\peripheral\spi

To make it blocking set event handler to NULL when calling nrf_drv_spi_init(). Do you see the same delay with this example?

RE: nRF51822 spi master transfer uncertain delay between bytes

Jason — Sat, 30 Apr 2016 02:10:14 GMT

Yes, I want to use blocking mode. I don't want to return during spi transfer.
I don't program the softdevice stack, and also don't initialize ble_app_initial. Additionally, I write a simple spi transfer, write one byte, read one byte and wait for NRF_SPI_EVENT_READY event, I found even in byte-by-byte transfer, the NRF_SPI_EVENT_READY event would delayed uncertain. I agree with what you mentioned, there may higher level interrupts, but I don't know what would be ?

RE: nRF51822 spi master transfer uncertain delay between bytes

Kenneth — Fri, 29 Apr 2016 11:18:04 GMT

Hi, "Blocking" means that the nrf_drv_spi_transfer() will not return until the transfer is done. However the execution might still be interrupted by higher level application interrupts and/or softdevice events. Could this explain your observation?