Arduino Wifi ESP8266 error - arduino

Question

i am trying to connect an arduino uno using esp2866 to my home router and i am getting th is error
C:\Users\john-\Documents\Arduino\newww\newww.ino:2:25: fatal error:
ESP8266WiFi.h: No such file or directory #include
^ compilation terminated. exit status 1 Error compiling for board
Arduino/Genuino Uno.

Answer 1

ESP8266WiFi.h is part of the ESP8266 core for Arduino. That core is used to add support to the Arduino IDE for directly programming the ESP8266. The file ESP8266WiFi.h is only accessible when you have one of the ESP8266 core for Arduino's boards selected from the Tools > Board menu. However, you are not directly programming the ESP8266 and do not have one of the ESP8266 core for Arduino's boards selected. You are programming the Uno and thus you will not be able to use ESP8266WiFi.h.

Answer 2

You need to use serial AT firmware on ESP8266 and connect the ESP8266 to UNO with two Rx and Tx pins. After that you will be able to send correct AT commands to open socket and communicate thru the Internet.
You can install AT firmware from here.
In the example given below, GPIOs on UNO 2 and 3 will be connected on the RX and TX of the ESP8266. Do not forget to cross connect the RX and TX on each other.
#include <SoftwareSerial.h>
SoftwareSerial wifiSerial(2, 3); // RX, TX for ESP8266
void setup()
{
Serial.begin(baud); // Serial for UNO output
wifiSerial.begin(9600); // Serial for ESP8266 AT input
}
void loop()
{
while(wifiSerial.available() > 0)
{
char a = wifiSerial.read();
if(a == '\0')
continue;
if(a != '\r' && a != '\n' && (a < 32))
continue;
Serial.print(a);
}
while(Serial.available() > 0)
{
char a = Serial.read();
Serial.write(a);
wifiSerial.write(a);
}
}
With this example, your SerialMonitor will be able to receive AT commands. You can write the AT command to connect to the Wi-Fi. Check some basic commands from here.
After you tested the commands and OK, you will put these commands into specific functions. i.e.:
void connectToWiFi()
{
//super simply
wifiSerial.write("AT+CWMODE=1\r\n");
wifiSerial.write("AT+CWJAP=ssid,pass\r\n");
}