Softdevice crashes with PPI

RE: Softdevice crashes with PPI

anderswb — Wed, 23 Jul 2014 09:14:47 GMT

Hi Håkon. Follow up question.

We tried changing the SD to S110-SD-v7 from S310 and updated the SDK to 6.0.0 by overwriting the /Source/ and /Include/ folders in our project folder. The IROM and RAM adresses has been updated as specified in the v7 migration guide.

Now we get some wierd error when initializing the GAP. The init code is pretty much the same as the one in the gap_params_init(void) function in the nrf51-ble-app-lbs project on your github. But our sd_ble_gap_device_name_set() function returns BLE_ERROR_INVALID_ATTR_HANDLE (0x3001) and the program keeps rebooting as a result.

Any ideas? We looked through all of the documentation, but there's no mention of anything we should be aware of in this regard.

RE: Softdevice crashes with PPI

anderswb — Wed, 23 Jul 2014 07:34:15 GMT

Thanks. That makes sense.

RE: Softdevice crashes with PPI

Håkon Alseth — Wed, 23 Jul 2014 07:24:56 GMT

Hi,

Since the softdevice uses parts of the NRF_PPI peripheral, it protects the whole peripheral, so that the application cannot access it directly (if you try, you'll end up in HardFault). So, using this protection, the only way we're allowed to access it is through the nrf_soc API (sd_ppi-prefixed functions). If you set up the PPI before starting the softdevice, the softdevice will only care about the PPI channel it needs and leave the others untouched. BTW: I'll send you a PM regarding your last question:)

RE: Softdevice crashes with PPI

anderswb — Tue, 22 Jul 2014 20:34:47 GMT

Hi Håkon

I found the information regarding the IRQ priorities while waiting for you reply, but thanks anyway.

I still don't understand the PPI stuff. I'm pretty confident that I'm not using any of the channels that are reserved according to the SD specifications. For some reason it works if I set it up before i start the softdevice. It's only if I set it up after I've started the SD that it chrashes. It's not really that important, but it's a little concerning i think. Any ideas?

On another note while I have your attention. :) Do you have any idea if it's possible for me to get access to the S110/S120 SD instead of the S320? For some reason I only get access to some of the stuff with the Dynastream module I'm using. Seems a bit wasteful for me to order a NRF51422, that I don't really need, just to gain access.

Thanks again.

RE: Softdevice crashes with PPI

Håkon Alseth — Tue, 22 Jul 2014 17:05:25 GMT

Hi,

The PPI is a restricted peripheral (see the S310 spec for more details), which means that this has to be accessed by the softdevice API when the softdevice is enabled.

You can configure the PPI prior to starting the softdevice, but you will have to make sure that any interrupts enabled at this point must be set to priority level '1' or '3', as these are the priority levels that the softdevice accepts.

Most likely, it's the Timer2 (or GPIOTE) interrupt priority that gives you this error code. Try calling:

NVIC_SetPriority(TIMER2_IRQHandler, 3);

Before starting the softdevice.

This library may be of interest to you: github.com/.../nrf51-pwm-library

Best regards, Håkon