Install ESP8266 core for Arduino IDE
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  1. 1.
    Install latest Arduino IDE.
  2. 2.
    Download and install Blynk library (follow instructions of the latest release package).
Then, open the Arduino IDE, then select in the menu: File -> Preferences (Arduino -> Preferences for Mac).
Click on Additional Boards Manager URLs button and add this link:
1
http://arduino.esp8266.com/stable/package_esp8266com_index.json
Copied!
In the Arduino IDE open: Tools -> Board -> Boards Manager . Search for esp8266 , and install it:

Troubleshooting

In case you see Error downloading http://downloads.arduino.cc/packages/package_index.json like this:
You need to find folder Arduino15 or .Arduino15 and remove all files inside with package word in name.
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