I'm running the RFA1 on several nodes with custom firmware. Most of their time is spend in RX_AACK mode. Everything works great for a while, but after a day or so, some of my nodes stop receiving. I can see that the CPU is running, regulator voltages are ok, radio registers appear to be fine (I can peek/poke over a USB port). However, I start getting a lot of PLL_UNLOCK interrupts, which generally never occur when things are working properly.
I'm running the filter tuning loops every two minutes. I also periodically cycle the radio through TRX_OFF and then back into receive mode. A reboot corrects the problem, so it seems like there is something internal to the radio that gets corrupted and starts preventing the PLL from locking.
I've searched high and low for any guidance on what to do with a PLL_UNLOCK interrupt. I haven't seen any code other than mine that actually enables it. The datasheet just says it indicates an unexpected PLL unlock (obviously), but gives no hints on what to do about it.
Anyone have any thoughts?