Version v4

• Using ESP8266 NON-OS SDK 3.0.0.
• Major refactoring and state machine based firmware.
• Improved ADC reading.
• Chip ID based initial device ID.
• Remove battery level measurement code.

Version v3.

• Docker based build system.
• Use SendGrid as E-mail notification backend.
• Read ADC during WiFi radio off to get better results.
• State machine around WiFi events and state changes.

Version v2 (Deprecated).

• Add changelog.
• Add WiFi AP search feature on the web interface.

Version v1 (Deprecated).

This is the initial release.