Very low power

[moozoo64]

As per https://tinker.yeoman.com.au/2016/05/29/running-nodemcu-on-a-battery-esp8266-low-power-consumption-revisited/

It would be great it the usart used its own internal 3.3V regulator
https://yeomanblog.files.wordpress.com/2016/05/option2schematic.jpg
Plus a TX pull down resistor.
This is so it doesn't consume power while not in use.

It would be great if there was a jumper to disable the AMS1117 so that an external battery + MCP1700 + 1000uf Electrolytic could be used instead (for burst transmission of sensor data).