You are obviously currently programming the ESP8266, not the Atmega328p. The board seems to have DIP switches on it. With those you can control, which chip is connected to which. The product description has the following table
1 2 3 4 5 6 7
ATmega328<->ESP8266 ON ON OFF OFF OFF OFF OFF
I agree with @Offer that using UART is the simplest solution to connect the devices.
I just want to suggest two alternatives:
Use an external analog to digital converter IC. Using the Arduino only for analog conversion is a bit over powered. E.g. the ADS1115 has a resolution of 16 bits and there's already a library, so usage should be easy.
The ESP8266's ...
As I see it, the most straight-forward way to connect 2 Arduinos is using their built-in UART (aka Serial port, TX/RX pins) communication.
There are many tutorials on this on Google, and a similar explanation can be found in this question:
Serial communication arduino mega and D1 Wemos Mini
However, there is a slight difference.
Arduino Mega has built in ...
The DevKit is a development board by ESP32 manufacturer Espressif to demonstrate ESP32 usage and to support prototyping.
The NodeMcu is a board by NodeMcu intended for the NodeMcu Lua language firmware.
There is no standard pinout. The labels on the DevKit are io pin numbers of the MCU.
You can use both development boards with the ESP32 "Arduino boards ...
I don't know why the answer below is accepted, as it clearly doesn't solve the question but also gives false information. In this answer @chrisl assumed that blinking green LED is what was programmed with sketch, but if you will open sketch used in this video and read comments in the source code, then this misconception will become obvious: actually red RX ...
َAbout first question I found after AT command AT+CWJAP="network","password" it takes a while to have active and ready wifi connection , so I used a 30 seconds delay after this command and then send sensor data toward thingspeak.com , now problem is solved .
Sir mane ardunio mega 2560 my programing k hy jo k different sensor k value lake display karty hy aur sir ab my us value ko server jo k thingspeak hy aus p bajna chahta ho sir aus k leye mane esp8266 node-mcu use kar raha ho to sir ab my chahta ho k arduino value lake node-mcu ko send kary aur node mcu phr server p sir in k leye serial communication chahyae ...