3in1 ESP TOOL

This is a low cost 3in1 tool for anybody working with ESP's or other similar MCU

It is a little longer than a typical TP4056 charger module (40x18mm) 

It connects to external power source or a computer via mUSB and has a CH340C working as a typical USB2TTL converter (operating at 3.3V).

Power to the CH340C is disconnected when external power source is removed to reduce idle power consumption.

A CN3153 charger IC charges a Li-Ion battery and keeps it charged while external power is present. 

A 3V3/800mA LDO generates 3V3 rail for CH340 & attached MCU. LDO is powered through a power path making sure the 3V3 output is not interrupted when external power fails, diverting to battery power.

Battery Charger with protection

USB2TTL 

3V3 UPS

Low cost and easy to make and use...