Inside GPIOTE interrupt handler the SPI transaction never ends

[alexislong73]

Hi,

I am sensing interrupts on a pin using GPIOTE. I can see the interrupts coming on the oscilloscope. The firmware also detects the interrupts. However once I am inside the interrupt function, if I want to do a SPI transaction (in my case it is to retrieve data conversion of an ADC), then I never end the transaction. In fact the MISO line works fine (on the first conversion) as I can see on the oscilloscope. However after the transaction is done, the SPI peripheral should issue an interrupt to say the transfer is done but it does not.

I have been careful to set the code as non optimized, and I have given higher priority for the SPI than for the GPIOTE. By the way the SPI works well in normal mode when I configure the sensor registers (I verified with the oscilloscope)

Here is the oscilloscope picture with DRDY (interrupt) and MISO on first conversion (on the next conversions the MISO stays low):

#

Here is the SPI transaction code in the GPIOTE interrupt handler code (where rc is successful but xfer_done does not get true:

RetCode rc = RetCode::SUCCESS;

xfer_done = false;

rc = m_spi->Transfer(NULL, 9, &spi_rx[0], 9, spi::NO_FLAGS);

ASSERT_ERR(rc);

while (!xfer_done) { WFE }

To recreate it, I would say that you need to set the GPIOTE priority level to 3 and SPI priority level to 2 and get interrupts with GPIOTE and try to do a SPI transaction.

I use the nRF52832 with SDK14 without softdevice.

Thanks

[alexislong73]

I found a solution. I have set .irq_priority in the SPI configuration to 1 instead of 6.

But then what's the difference between the peripheral priority in the sdk_config.h and the priority of theSPI1 configuration (.irq_priority)?

[Håkon Alseth]

Hi,

 

Unless specified, the default configuration will read the interrupt priority from the sdk_config.h file.

To override this, you need to change the input member .irq_priority provided to the nrf_<driver>_init() function.

 

Kind regards,

Håkon

[alexislong73]

I see, thus I was overwriting it before to a priority above the SPI. Alright, thanks this solves my issue.

Kind regards