Re: RN4870 %Unknown Device% meaning
costa, based on the explanation I received the reset chip should not be necessary. The issue was when the device was in the middle of writing to some memory location, if the voltage dropped below some level the address to write to would become 0x00, and then the next few registers at that location would get destroyed. There is sensitive calibration information and such at that location. The new firmware saves these registers in multiple locations and then checks those registers on boot up and restores them if they have been altered.
Furthermore, one of the devices we had bricked even with the voltage monitor so I don't think it was actually helping this issue.
But I would say in general, you should make your design such that the Bluetooth module and any MCU's or other digital components shutdown if the voltage is browning out. All that stuff is going to go into an unknown state at lower voltage.