ANCS resets after deleting bond on dev board

RE: ANCS resets after deleting bond on dev board

Antonio — Mon, 21 Dec 2015 02:04:34 GMT

I did have an error handler.

My problem, I know now, is that I am using a timer for part of the exception handling and it is running on app_low, and I was trying to solve the problem on a SD callback.

So the solution was to set a flag and handle the exception on main.

Thanks Anders!

RE: ANCS resets after deleting bond on dev board

Anders Strand — Wed, 09 Dec 2015 13:36:51 GMT

Most events originate from the softdevice. It will send the event using a software interrupt with priority APP_LOW. Everything called from within that software interrupt is still in APP_LOW priority. See this picture of event flow. Practically speaking; Anything that is not called from main(), will have APP_LOW priority or higher.

RE: ANCS resets after deleting bond on dev board

Antonio — Wed, 09 Dec 2015 09:07:34 GMT

Wow, I feel like a newbie now. I thought that the timer was working through interrupts and that I would get a call if I was on the same priority. Or, now that I think of it, this one error is a callback to the device_manager_evt_handler. What priority would that be?

RE: ANCS resets after deleting bond on dev board

Anders Strand — Wed, 09 Dec 2015 08:58:26 GMT

It really depends on the implementation of your error handler. Note that the event that come from the softdevice will run on the same priority as app_timer. If you are for example are doing an infinate while loop somewhere (other than main()), you will block the timer.

RE: ANCS resets after deleting bond on dev board

Antonio — Wed, 09 Dec 2015 08:03:03 GMT

Thank you Anders! In my board I am doing my own implementation of APP_ERROR_CHECK before I actually send it to APP_ERROR_CHECK for reset (after pressing a button that I am looping directly on the IO). The problem I am having is that when I intercept the error for some reason the timers do not work anymore. I have a timer that is constantly driving an LED for status, and that one stops working. Do you know if when an error condition is sent the timers from app_timer stop working? Thanks!

RE: ANCS resets after deleting bond on dev board

Anders Strand — Tue, 08 Dec 2015 10:25:52 GMT

If you want to filter the error, dont pass it to APP_ERROR_CHECK (APP_ERROR_CHECK(event_result); in device_manager_evt_handler) , but implement your own handling of the event.

RE: ANCS resets after deleting bond on dev board

Anders Strand — Tue, 08 Dec 2015 10:23:26 GMT

Hi.

When the phone has bonding data and the device doesn't, it is not really any easy way out. The phone will try to encrypt the link with the existing encryption keys, and the peripheral device must deny these attempts because it does not have the keys. The only solution to this is to delete the device from the phone bluetooth settings.

You mentioned this potentially being an issue when using DFU. You have the option to keep bond data when doing DFU, so this should not be a problem.

About the board resetting or freezing when an error occurs: This is how the default error handler reacts on errors. It resets by default, and freezes (while(1)), when DEBUG is defined.

From the documentation of app_error_handler:

@warning This handler is an example only and does not fit a final product. You need to analyze * how your product is supposed to react in case of error.

It is up to the developer to decide how the application should react to different errors.

The return code 0x88 comes from

event_result = p_ble_evt->evt.gap_evt.params.auth_status.auth_status;

The status is BLE_GAP_SEC_STATUS_UNSPECIFIED. This status describes that the authorization failed with an unspecified reason. (As we can see on event 1415 in the sniffer log).

RE: ANCS resets after deleting bond on dev board

Antonio — Mon, 07 Dec 2015 23:33:31 GMT

Hi Anders. I checked some more and the problem with this error the stack is sending on the callback, is that somehow the SD stack is unstable at this point and I cannot try to recover. The timers are not responding anymore and the slot I am using with sd_radio_session_open(m_timeslot_callback) to do extra things with the radio is not responding either. Is there a way to catch this strange error (0x88) and have the SD still operational so I do not have to proceed with reset?

RE: ANCS resets after deleting bond on dev board

Antonio — Mon, 07 Dec 2015 21:44:29 GMT

Thanks Anders! It is returning an error 0x88 in the call back device_manager_evt_handler. Tha base of the error is 0 so it is a global error, but I did not find the documentation about that error. Can you point me in the right direction?

RE: ANCS resets after deleting bond on dev board

Anders Strand — Mon, 07 Dec 2015 13:38:49 GMT

The APP_ERROR_CHECK call will end up in app_error_handler in app_error.c. If DEBUG is defined, it will do the following:

m_error_code = error_code;
m_line_num = line_num;
m_p_file_name = p_file_name;

UNUSED_VARIABLE(m_error_code);
UNUSED_VARIABLE(m_line_num);
UNUSED_VARIABLE(m_p_file_name);
__disable_irq();
while(1) ;

Here you can see the error code, the line where is was coming from, and the file it was coming from.

RE: ANCS resets after deleting bond on dev board

Antonio — Mon, 07 Dec 2015 12:58:16 GMT

I cannot catch where is resetting. I already tried all of the APP_ERROR_CHECK in the ANCS example to try to pin it down. I think it might be reseting inside the SD. I was hopping you would have better luck trying to find exactly where it resets. That is the reason I documented how to reproduce the problem.

RE: ANCS resets after deleting bond on dev board

Anders Strand — Mon, 07 Dec 2015 12:45:16 GMT

I see. Are you using the ANCS example from the SDK? If the device reset, it is probable because APP_ERROR_CHECK encounters an error. Can you try to find out which function returns the error? Add either a print or breakpoint in app_error.c

RE: ANCS resets after deleting bond on dev board

Antonio — Fri, 04 Dec 2015 19:46:15 GMT

There are a thousand situations for which the bond could be deleted from the peripheral device, for which iOS would not know beforehand. A common example would be that another iOS or Android did a DFU. The big problem is ANCS resetting instead of having a procedure to re-bond or a check-point to make a decision instead of resetting.

RE: ANCS resets after deleting bond on dev board

Anders Strand — Fri, 04 Dec 2015 13:03:00 GMT

When you clear the bond on only one of the devices, the other one does not know about it. To fix this, you should delete the bond info on the iphone as well.

Is this a normal use case for your device? Do you need to make this scenario work?