Since Post 1, the following changes have been made to reduce the sleep current from 110uA to 26uA, and the battery state can be monitored for a long time.
- Instead of Sleep/Wake-up by RTC interrupt, use RTOS delay() which consumes less current.
- Do not let Flash sleep because we do not know how to recover from DeepPowerDown mode.
- Periodically display the battery voltage status with LEDs.
