Based on the debug information you have given, and your project, the error seems to come from line 180 (0xB4) in COMP-adxl372_spi.c which gives error_code 17 (0x11). This equals NRF_ERROR_BUSY.
ret = nrfx_spim_xfer(&spi, &xfer_desc, 0);
APP_ERROR_CHECK(ret);
/**
* @brief Function for starting the SPI data transfer.
*
* Additional options are provided using the @c flags parameter:
*
* - @ref NRFX_SPIM_FLAG_TX_POSTINC and @ref NRFX_SPIM_FLAG_RX_POSTINC<span></span>:
* Post-incrementation of buffer addresses. Supported only by SPIM.
* - @ref NRFX_SPIM_FLAG_HOLD_XFER<span></span>: Driver is not starting the transfer. Use this
* flag if the transfer is triggered externally by PPI. Supported only by SPIM. Use
* @ref nrfx_spim_start_task_get to get the address of the start task.
* - @ref NRFX_SPIM_FLAG_NO_XFER_EVT_HANDLER<span></span>: No user event handler after transfer
* completion. This also means no interrupt at the end of the transfer. Supported only by SPIM.
* If @ref NRFX_SPIM_FLAG_NO_XFER_EVT_HANDLER is used, the driver does not set the instance into
* busy state, so you must ensure that the next transfers are set up when SPIM is not active.
* @ref nrfx_spim_end_event_get function can be used to detect end of transfer. Option can be used
* together with @ref NRFX_SPIM_FLAG_REPEATED_XFER to prepare a sequence of SPI transfers
* without interruptions.
* - @ref NRFX_SPIM_FLAG_REPEATED_XFER<span></span>: Prepare for repeated transfers. You can set
* up a number of transfers that will be triggered externally (for example by PPI). An example is
* a TXRX transfer with the options @ref NRFX_SPIM_FLAG_RX_POSTINC,
* @ref NRFX_SPIM_FLAG_NO_XFER_EVT_HANDLER, and @ref NRFX_SPIM_FLAG_REPEATED_XFER. After the
* transfer is set up, a set of transfers can be triggered by PPI that will read, for example,
* the same register of an external component and put it into a RAM buffer without any interrupts.
* @ref nrfx_spim_end_event_get can be used to get the address of the END event, which can be
* used to count the number of transfers. If @ref NRFX_SPIM_FLAG_REPEATED_XFER is used,
* the driver does not set the instance into busy state, so you must ensure that the next
* transfers are set up when SPIM is not active. Supported only by SPIM.
*
* @note Peripherals using EasyDMA (including SPIM) require the transfer buffers
* to be placed in the Data RAM region. If this condition is not met,
* this function will fail with the error code NRFX_ERROR_INVALID_ADDR.
*
* @param p_instance Pointer to the driver instance structure.
* @param p_xfer_desc Pointer to the transfer descriptor.
* @param flags Transfer options (0 for default settings).
*
* @retval NRFX_SUCCESS If the procedure was successful.
* @retval NRFX_ERROR_BUSY If the driver is not ready for a new transfer.
* @retval NRFX_ERROR_NOT_SUPPORTED If the provided parameters are not supported.
* @retval NRFX_ERROR_INVALID_ADDR If the provided buffers are not placed in the Data
* RAM region.
*/
nrfx_err_t nrfx_spim_xfer(nrfx_spim_t const * const p_instance,
nrfx_spim_xfer_desc_t const * p_xfer_desc,
uint32_t flags);
NRFX_ERROR_BUSY = If the driver is not ready for a new transfer. Which again means you need to check your code.
