SPI when advertising not working

[danimalia]

Hi 

I am using SPI to talk to an LIS2DH with an NRF51822. I have merged the SPI Master example with the ble_app_rscs example and as soon as the ble advertising begins, my SPI interrupts no longer work and I end up in the hard fault. I have changed the IRQ priority to high but it still does not work. 

I am using SDK8.0.0 - I know it's old, it's the only SDK version I could get to work with the free version of Keil. 

[Nguyen Hoan Hoang]

Try to use app_scheduler to differ interrupt processing. 

void SchedIrqHandler(void * p_event_data, uint16_t event_size)

{

...

}



void IRQ_Handler()

{

    uint32 evt = 1;

    app_sched_event_put(&evt, sizeof(uint32_t), SchedIrqHandler);

}

[danimalia]

thanks. what would be the equivalent app_scheduler to use in SDK 8? 

[Nguyen Hoan Hoang]

It doesn't work after advertisement_start() is normal.  The spi_config is taking to much time.  Softdevice does like it.  There are also to many delays in your get_acc_data.  

[danimalia]

That’s what I thought, I changed it to only call spi_config once and then removed all the delays in get_acc_data and it still hangs

[Nguyen Hoan Hoang]

Where does it hang exactly ? Are there any errors returned by the SDK ?

[danimalia]

in the hardfault: 

the call stack is also not helping me determine how it got there...

[danimalia]

let me re-phrase that: 

the processor doesn't hang - I can still see me ble advertising packets and connect to it etc. as soon as I call spi_master_init or spi_send_recv after I have called advertising_init, nothing happens. I have scoped the SPI lines and nothing happens on them. 

If I put breakpoints on spi_master_init or spi_send_recv, I end up in the hardfault if I try step over those functions. 

seriously confused here

[Nguyen Hoan Hoang]

When softdevice is running,  you cannot debug.  You can breakpoint only.  Then it will crash if you try to step.  You need to restart every time you break.  With softdevice, you cannot hold the processor too long so the SPI init and data reading has to be done quickly.  Calling SD function within interrupt also not permitted.  Hence require to use App Scheduler.  When you hold the process too long, SD will crash.  This mean you SPI init and read data are taking too long to complete.

[danimalia]

OK, I understand thank you. 

Can you how me where to place and how to call the app_scheduler for this situation please? the current interrupt is in spi_master.c: 

void SPI0_TWI0_IRQHandler(void)
{
    if ((NRF_SPI0->EVENTS_READY == 1) && (NRF_SPI0->INTENSET & SPI_INTENSET_READY_Msk))
    {
        NRF_SPI0->EVENTS_READY = 0;

        volatile spi_master_instance_t * p_spi_instance = spi_master_get_instance(SPI_MASTER_0);

        spi_master_send_recv_irq(p_spi_instance);
    }
}

[Nguyen Hoan Hoang]

I already shoed you the code previously.  You can also find a lot of examples in the SDK.

[danimalia]

I'm sorry, but I don't understand exactly how to convert the existing spi code to what you posted above. can you provide a bit more detail, or pointers to where I can find more examples? 

going through the forums it seems that a lot of people had the same problem when trying to get spi master to work with softdevice present, but I can't find a definitive solution. 

thank you.