Hi,
I am using a nRF52840 and SDK 15.2, and Soft Device S140 (BLE), where the device is battery powered.
In certain modes, the device sleeps to System Off mode, and wakes when a NFC field is detected, by resetting the microcontroller.
This is working fine.
In other modes, the device sleeps in System On mode, and wakes using a RTC timer wakeup which generates an interrupt bringing the micro core on, and continuing execution at the point in code after it went to sleep (after executing the interrupt).
I would also like to configure the micro so that if an NFC field is detected it also would wake the micro in addition to the RTC Timer.
The two Nordic examples I have are but cannot use either:
- One where the MCU wakes from System *Off* by performing a reset - I do not want the MCU to reset, I just want it continue.
- One where a periodic timer wakes the MCU from System On, and checks for the NFC field - I do not want a periodic wakeup due to battery life concerns.
Is it possible to wake from System On using the NFC Peripheral alone when a Soft Device is present, and if so what is the configuration for the NFC peripheral and state of the Soft Device (enabled/disabled)?
The purpose is to have BLE advertising off to minimise battery consumption, until an NFC field has been detected, then BLE advertise for a short period (eg 20mSec for 30secs).
It is essential that the method does not reset the micro, which effectively means the micro is sleeping in System On mode.
It is not necessary to transfer data via NFC or to emulate any tags, as NFC is simply a trigger to start BLE advertising.
Thanks
Dermot
