Node MCU ESP8266

I am planning to use this module with arduino , Need clarification on below

  1. weather it can be integrated with arduino UNO?

  2. weather any external 3.3v to be added to power on??

3)How its differ from esp8266 esp-01 & Esp8266-12E?

4) which more recommended product for IOT application using arduino UNO. where i can easily config and integrate with arduino UNO

with NodeMcu or Wemos board you do not need an Uno in most projects.

1.) yes, read the guide

2.) yes, with module; not, with dev board like nodemcu or Wemos

3.) count of accessible pins

That NodeMCU board (and a Wemos D1 mini, and many others) should be used stand-alone (without an Uno).
It has everything you need onboard, including ESP-12, USB>3.3volt supply and USB<>Serial chip.

An ESP-01 is a bare ESP8266 WiFi module with 512kB of flash, and is usually used as WiFi-only module together with an Uno. But can also be used stand-alone with a 3.3volt supply. Only a few I/O pins are available to the user. Programming is a hassle.
An ESP-12 is also a bare WiFi module, much like the ESP-01, but with 4MB of flash and more I/O pins broken out.

You coud say that an ESP-01 or ESP-12 is an engine, and a NodeMCU is a car.

NodeMCU board Can be used with arduino Uno?? Its seem like separate board where it available with various peripherals. and can code to access the digital& analog io

NodeMCU cant be controlled through arduino UNO board.

Can someone suggest me model that can be used for IOT application. Directly used with arduino Uno or PIC controller
Like wise sheilds in arduino uno , where TX,RX, Gnd , VCC can be given to get started working.

Suggest me any popular esp8266 shield that have these facility.

I have Esp8266 -12E version but i am facing issue while communicating.

I have a temp logger inside with a Wemos, DS18B20 with 4k7 resistor, and cellphone (USB) charger.
Serves up a graphical web page with temps from the last 3 months (so far).

I have another one with a dozen or so different dashboard pages for my home lighting system.
It is also controlling several 16-channel LED driver boards (with bare ESP-12 modules).
That setup is nothing more than a WeMos and a cellphone charger.

You might not need an Uno.
Many sensors have an I2C interface, and you can connect a bunch of them to a single Wemos/NodeMCU.
Tell us what you want to do, so we can give better advice.

here is my project originally with Uno with esp8266, now with Wemos D1 R2

I have energy meter Which works on Modbus RTU protocol. I wanted to pop data from energy meter to cloud . This main application i am testing.

But i havent done iot application so far. basic level i am trying once it connected i connect through energy meter & transmit data serially using TX & RX line.

In order to basic level of testing i wanna try this concept.

Most of the things the Uno can, the NodeMCU can. Sensors can be connected to both - just keep the difference in voltage in mind.

The NodeMCU is designed to be used as standalone, it actually has an ESP-12.. module on board (should be the E or F version). The ESP-01 is designed to be used as WiFi coprocessor for use with an Arduino or other MCU.

when we say "Arduino" we usually refer to the current UNO model with 6 analog pins.
the NANO offers access to all 8 analog pins, so you can get 2 more pins with that device.
the Pro Micro use the 32U4 chip and is the same as the Leonardo and offers quite a few differences.'
the Pro Mini uses the 328 and functionally the same as the UNO and NANO chip.

the ESP8266 in WemosD1 or NodeMCU offer 9 digital pins with access to TX and RX to make 11
There is only one ADC input and it is only 1V full scale, but depending on the board, you have choices. the NodeMCU has 3 pins available for the one ADC. One set of pins puts your analog value into a voltage divider, the other requires you scale it externally.

development is about the same on any of the devices. This is why so many of us use the ESP8266 as a single board for our projects.

and as with any of these boards, you can add either a bi-directional port expander or shift registers, or even multi-channel ADC chips.

on the horizon is the ESP32 with (I think) 3 dedicated Analog inputs (pins 34 to 39). and all the other pins available as either analog in, but also outputs. (similar to how the UNO handles the AI pins.

that chip offers some benefits, like many more pins and all can do Analog in, but it has some peculiarities in that while all pins have hardware functions, any pin can be re-directed through a MUX circuit.

While all of the ESP chips, in all varieties and all packages, CAN be controlled and used with an Arduino UNO, we suggest that you evaluate if the ESP does not offer faster and more functions than the UNO.

I think that as soon as you start using a Wemos D1, you find that the amount of stuff you can do becomes more than you expected.

as a note, the nodeMCU and Wemos both offer the same number of usable pins. The nodeMCU breaks out some that you cannot use because they are dedicated to the memory chip.

to use an ESP8266 use more pins, check out this video : more pins

I trust that I did not make too many mistakes in this post.

(should be the E or F version).

The ESP-01 is designed to be used as WiFi coprocessor for use with an Arduino or other MCU.

AFAIK the only difference is the shape of the circuit board aerial.
The F being the 'improved' version.

Not a problem to use the ESP-01 stand-alone if only the TX/RX lines are used for modbus comms.
The TX/RX lines are free after basic programming, and new sketches can be uploaded OTA (wireless) after that.
The only problem with the ESP-01 stand-alone is that it needs some supporting parts and a 3.3volt supply.

as a note, the nodeMCU and Wemos both offer the same number of usable pins. The nodeMCU breaks out some that you cannot use because they are dedicated to the memory chip.

By changing the way the internal flash is accessed you can free up two of those - GPIO9 & 10 iirc. But it's a bit hit or miss it seems, reading the stories on the Internet, to the extent that I never bothered to even try.