The program terminates at NRF_BREAKPOINT_COND while using interrupts with timers

[Abhigya]

Hey,

I am using nRF52840-DK and SDK 15.2 and working on 802.15.4. The transmitter is sending beacons at an interval of 2sec. The receiver is scanning the network for beacons every 100ms. On not receiving a beacon it must sleep for some time, wake up again and then scan for beacons again. 

I have been able to implement scanning the network for 100ms, initializing a timer and sending the device to sleep mode for a specific amount of time. When the device has to wake up from sleep mode, I am generating an interrupt. However, the device is not able to enter the interrupt function and goes straight to NRF_BREAKPOINT_COND in debug mode.

On looking at the functions where the errors are once the program has reached NRF_BREAKPOINT_COND:

The command at line 0x00010313 of void assert_nrf_callback(short unsigned int line_num= 0x0003, const uint8_t* filename=0x00010313) is :

 

I can't understand what this means and how to solve it.

The timer initialising function is:

The interrupt function is:

The part of the function where I am calling the timer function and sending the device to sleep mode is:

After the interrupt has been serviced, the program execution should start from this function where it had been left. However, it is going to NRF_BREAKPOINT_COND.

How do I solve this error?

[Susheel Nuguru]

However, the device is not able to enter the interrupt function and goes straight to NRF_BREAKPOINT_COND in debug mode.

Can you show us the call stack when this happens so that we can understand the context in which this error occurs.

[Abhigya]

[Susheel Nuguru]

In the timer2init function, it seems that you enabled the interrupt for TIMER2_IRQn, but you did not set the priority of this interrupt, This would give it a default of highest priority 0,which would interfere with Radio activity. Can you try to set the priority of the timer2 to something lower (higher in value) priority and see if that changes the behavior?

[Abhigya]

I've changed the priority but it doesn't bring any change in behaviour.  

I hope I'm changing it correctly.

Edit: I was wondering if this link would be helpful. I tried to disable RADIO_IRQn interrupt while the timer function generated the Timer interrupt. In that case, the timer is working fine, the system is going into sleep mode, waking up from generating interrupt but then it enters the while(1) loop of sleep mode (after exiting from timer2init() ) and doesn't come out. 

It gets stuck here:

This wasn't happening before and the system could come out of the sleep mode automatically once the timer was over.

[Susheel Nuguru]

Are you configuring the RADIO interrupt yourself? when using the BLE softdevice stack, you should not touch any configuration of the RADIO. When you were accessing NVIC directly, I assumed you were not using softdevice. If you are using softdevice and have enabled in your program, then you cannot access NVIC directly, but access it through sd_nvic api.

Disabling RADIO makes rest of your system work as intended, would mean that something is wrong with the RADIO configuration.

[Abhigya]

No, I am not using any softdevice and I am not configuring the RADIO interrupt myself. 

[Susheel Nuguru]

The command at line 0x00010313 of void assert_nrf_callback(short unsigned int line_num= 0x0003, const uint8_t* filename=0x00010313) is :

 I think we should focus on the above line.

Can you please read the memory at 0x00010313 in Ascii format so that we know the filename and linenum that caused this error. We can focus on that line which caused this error and move ahead from there.

[Abhigya]

I am sorry but what is reading the memory in 'Ascii format'? 

[awneil]

It just means that you display the values as ASCII-coded text; ie

• 0x31 displays as '1'
• 0x39 displays as '9'
• 0x41 displays as 'A'
• 0x5A displays as 'Z'
• 0x61 displays as 'a'
• 0x7A displays as 'z'
• etc, etc, ...