Watch dog and while statement

RE: Watch dog and while statement

peter_100P — Sun, 29 Mar 2020 21:02:59 GMT

Every embedded developer worth their salt must read this:

http://www.ganssle.com/watchdogs.htm

RE: Watch dog and while statement

Hansome — Sat, 10 Aug 2019 03:24:43 GMT

In other words, How to feed the watch-dog is better?

RE: Watch dog and while statement

Edvin — Fri, 09 Aug 2019 11:59:02 GMT

Hi Hansome,

I gave this some more thought after consulting with my colleague who handles this ticket.

Maybe you shouldn't set the app_timer's priority so high. It may result in some unexpected behavior because other threads that possibly needs access faster can't get it.

I suggest that you bump the priority on app_timer back to the default value (6?) and then rather skip the while(!fds_ready){}.

I agree that sometimes you need to wait for _fds_ready, but I suggest that you do this update in your main context instead of in the FDS interrupt.

RE: Watch dog and while statement

Edvin — Mon, 05 Aug 2019 08:23:57 GMT

I don't know if you actually opened the link from my previous reply.

levels 0, 1 and 4 are reserved for the softdevice.

[quote user="Edvin Holmseth"]I don't know whether you are using the softdevice[/quote]

Do you use the softdevice?

[quote user="Edvin Holmseth"]Try to set it to 3, and see if that helps.[/quote]

so you tried 0, 1 and 5. Did you try 3?

Check out the link, and pick a value that is higher than the softdevice's "none-time-critical processing" and "SoftDevice memory protection" So you can choose either 2 or 3. If 2 works, then it is fine.

RE: Watch dog and while statement

Hansome — Mon, 05 Aug 2019 00:14:15 GMT

Only setting APP_TIMER_CONFIG_IRQ_PRIORITY to 2 can works, why?

RE: Watch dog and while statement

Hansome — Mon, 05 Aug 2019 00:10:48 GMT

// <o> APP_TIMER_CONFIG_IRQ_PRIORITY  - Interrupt priority
 

// <i> Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice
// <0=> 0 (highest) 
// <1=> 1 
// <2=> 2 
// <3=> 3 
// <4=> 4 
// <5=> 5 
// <6=> 6 
// <7=> 7 

#ifndef APP_TIMER_CONFIG_IRQ_PRIORITY
#define APP_TIMER_CONFIG_IRQ_PRIORITY 0
#endif

There has been no improvement with the value=0 or value=1 or value=5.

RE: Watch dog and while statement

Edvin — Fri, 02 Aug 2019 12:17:29 GMT

Hi Hansome,

It sounds like the app_timer interrupt is not allowed to access the CPU until you are done with your FDS events. They are probably running on the same interrupt priority.

I don't know whether you are using the softdevice, but you can take a look at the interrupt priority levels for the nRF52810 here.

Try to increase the interrupt priority (lower number = higher priority) on the app_timer.

Look for APP_TIMER_CONFIG_IRQ_PRIORITY in sdk_config.h. Try to set it to 3, and see if that helps.

Best regards,

Edvin