Mind double-checking this comment? Would be much appreciated. I've written this a while ago, and I *think* it should be correct, as I've tested this for months now, but RTIC <-> normal interrupts is still confusing

```
// RTIC module
// unused PWM interrupts are used as RTIC interrupts.
// never use prio 0, 1 and 4, as they are reseved for the softdevice (RTIC 8, 7 and 4)
// only use 2 (RTIC 6) and 3 (RTIC 5) (higher-than-softdevice-prio) and 5-7 (RTIC 3-1) (under the lowest-level softdevice)
// https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsds_s140%2FSDS%2Fs1xx%2Fprocessor_avail_interrupt_latency%2Fexception_mgmt_sd.html
// Also, don't toch the softdevice-reserved  peripherals, or you'll get a crash.
// The forbidden peripherals are: POWER, CLOCK, RADIO, RTC0, TIMER0, RNG, ECB, CCM_AAR, TEMP, SWI5_EGU5, SWI2_EGU2
// Also don't touch the other SWIx_EGUx interrupts, the softdevice doesn't like that either.
// SWI0_EGU0 should actually work. Still.
```