Do I need to change the interrupt priority when using BLE

[Yogesh]

Hi,

I am using BLE UART application with softdevice S132 on nrf52832 board. I wrote a code where where i am using systick interrupt, GPIOTE interrupt. Also code has SPI0 ,Timer0, SAADC modules. Code is working fine without BLE .But now i have to add my application over BLE UART application. Do i need to change the priorities for those interrupts???What all changes i am supposed to to make in my application code????

[Sigurd]

Hi,

Interrupt priorities 0,1,4 and 5 are reserved for the SoftDevice. Your application can use priorities 2,3,6 and 7. The SoftDevice also uses TIMER0, so you will need to switch to TIMER1. Systick is sourced by the same clock as the CPU, which is turned off when going to sleep(WFE/WFI), so I recommend that you look into using the app_timer instead.

[Yogesh]

HI,

Thanks for the reply. I am able to change the priorities of both systick interrupt, GPIOTE interrupt to 7 and 6 repectively. also I could change the Timer0 to Timer 1. I didnt understand why i cant use Systick??why source clock gets turned off???would you please elaborate??

[Sigurd]

In the SDK BLE examples the GPIOTE priority is usually set to 7. If you don’t set the correct priority you will typically get an assert/error. The CPU is placed in sleep mode to save power between events/interrupts, and the CPU clock is therefore turned off. The nRF52 implementation of systick uses the CPU clock, so systick won’t return any interrupts when the CPU is in sleep/low-power mode.

[RK]

Yes SYSTICK is turned off when the device sleeps, so it's not that useful. Is there a reason you put multiple question marks after each question????????????????????????

[Yogesh]

Thanks . If i comment down the power_manage(); will systick work?

[Yogesh]

also i am using SPI0 interrupt.What precautions do i need to be taken? I am waiting for the reply.