problem with nRF52832 BLE + SPI + FreeRTOS

RE: problem with nRF52832 BLE + SPI + FreeRTOS

bjorn-spockeli — Thu, 20 Jul 2017 09:07:45 GMT

Ok, let us know when you have investigated this further.

RE: problem with nRF52832 BLE + SPI + FreeRTOS

segFault — Thu, 20 Jul 2017 08:59:34 GMT

Initially I thought it helped. But now I see that the issue just got more intermittent. I need some time to check everything. And I think it only happnes in scan mode. After establishing a connection I haven't seen any issues so far.

RE: problem with nRF52832 BLE + SPI + FreeRTOS

bjorn-spockeli — Thu, 20 Jul 2017 08:55:54 GMT

@segFault: Did you resolve the issue by providing an event handler when calling nrf_drv_spi_init()?

RE: problem with nRF52832 BLE + SPI + FreeRTOS

gkovelman_tap — Thu, 20 Jul 2017 06:53:12 GMT

Maybe it's a task priority issue. Anyway, if you can, try to use the GPIOTE & interrupts for detecting GPIO events. Same with SPI, use semapores/signals to send messages between the interrupts and the tasks.

RE: problem with nRF52832 BLE + SPI + FreeRTOS

segFault — Wed, 19 Jul 2017 22:07:37 GMT

It sort of worked. I had some other code that was also causing issues in the display task (polling for button connected to a GPIO) and after adding a handler and removing the button code it seems to work reliably now.

I'm not sure if it wasn't also caused by a very short vTaskDelay(2) which I used for fast checking the GPIO.

So, yes. If anybody wants to use SPI + BLE, passing a handler to the init function is the way to go.

Thanks gkovelman_tap for help!

RE: problem with nRF52832 BLE + SPI + FreeRTOS

segFault — Tue, 18 Jul 2017 14:19:45 GMT

Thank you, I'll give it a try later today.

RE: problem with nRF52832 BLE + SPI + FreeRTOS

gkovelman_tap — Tue, 18 Jul 2017 14:13:15 GMT

Yes, and use semaphores. xSemaphoreTake right after transmitting and

if (xSemaphoreGiveFromISR (semaphore_id, &taskWoken) != pdTRUE) { return osErrorOS; } portEND_SWITCHING_ISR (taskWoken);

in the handler (since it's in interrupt context)

**example copied from CMSIS_OS

RE: problem with nRF52832 BLE + SPI + FreeRTOS

segFault — Tue, 18 Jul 2017 13:29:52 GMT

No, but I gave it a quick try earlier. Maybe I didn't code it right. I'll have some time in the evening to rewrite and test it.

Do I need to call a portYIELD_FROM_ISR from such handler in case of using it with FreeRTOS?

RE: problem with nRF52832 BLE + SPI + FreeRTOS

gkovelman_tap — Tue, 18 Jul 2017 13:17:47 GMT

the SPI driver shouldn't busy wait. do you have a callback handler that was supplied to the nrf_drv_spi_init?

RE: problem with nRF52832 BLE + SPI + FreeRTOS

segFault — Tue, 18 Jul 2017 12:57:23 GMT

Sorry, I forgot to mention that. Yes, I'm using SPI0 channel with EasyDMA.

I did a couple of checks and I think that it may have nothing to do with FreeRTOS. I moved it out of the way and the problem still exists. That's "good", since there are more examples of BLE + peripheral than OS.

RE: problem with nRF52832 BLE + SPI + FreeRTOS

gkovelman_tap — Tue, 18 Jul 2017 12:52:48 GMT

Are you using the SPI driver with EasyDMA?