As part of the ongoing development, I wrote some lines of code that enables low power features to extend the run time of the device.

Hall Effect Sensor - this is good as a wireless button to trigger the module

EFM8 Snooze Mode - When the EFM8 goes into Snooze mode, it stops code execution and turns off all clocks - this drops power consumption from about 5mA to 30uA.

Bluetooth Module Sleep Mode - When the Bluetooth module goes into sleep mode, it draws 830uA, down from an average of 9mA @3.3V

This cuts down power draw from 14mA to 1mA, approximately 14 times less, which extends the runtime of the embedded device.

This is just the low-hanging fruit however. Further energy savings can be gained from the Bluetooth module by putting a transistor in-line with the power supply, the BLE unit can be turned off completely. This means that the device can be put on standby for 180 days on a coin cell.

Finally, if the Hall effect sensor circuit is designed so that it cuts off power from the coin cell completely, then the device can be on standby for a long period of time.

Ref: https://usermanual.wiki/City-Hong-Teng-Yu-Da-Electronic-Technology/JDY-08/html