How to make wifi thermometer on esp8266 without adruino?

Question

Electronics

Write firmware for the esp8266 stone itself, not use it as a peripheral for adruino. Why feed an adruin with a battery if the esp has a brain? I haven’t dealt with electronics for a very long time, so the questions will be stupid.
The final goal: a small box with a battery that responds to the current temperature in degrees using a primitive homemade binary UDP protocol.
The plan is something like this:
1) ESP-12E ru.aliexpress.com/item/New-version-ESP-12E-replace...
2) USB-UART adapter ru.aliexpress.com/item/FT232RL-FTDI-USB-to -TTL-Ser...
3) Stabilizer 5->3.3 ru.aliexpress.com/item/DC-5V-to-3-3V-Step-Down-Pow...(they say there are never enough circuits built into USB-UART - they don’t pull as much as esp is needed in some modes).
4) DS18B20 -- 1-wire digital thermometer.
Questions.
1) Explain about two COM ports on esp8266. I heard there is a second TX in there which is somehow useful for debugging. Where is it on the ESP 12E pinout and how to connect them to the COM adapter? Does the above (point 2) adapter have two com-ports? Can you recommend one, where is it?
2) How to power the device in the field? Can I use 2-3 finger batteries? But they have 1.2 volts * 3 = 3.6, higher than 3.3. Does the device die?
3) How to communicate with a 1-wire device, I'll try to figure it out on Google. As I understand it, we take any GPIO and pull this leg. Protocol: www.maximintegrated.com/en/app-notes/index.mvp/id/74it is not necessary to implement, you can find a ready-made piece of code. But it can be realized, it does not look like rocket science.

Answer 1

I would take such a wemos there is a built-in stabilizer (power supply 5V and 3.3) and there is a uart. There are ready -made shields for connecting batteries. You can use arduino ide.

Answer 2

I would use https://github.com/nodemcu/nodemcu-firmware
You can also try esp8266.ru/forum/forums/ESP8266-Arduino-IDE but it's still damp, but I think it can handle 1-Wire.
It is better to use a stabilizer for powering.
Additional TX on GPIO2 (according to Chinese docks).
I have 2 pieces died it is not clear from what ...