ESP8266 standalone

ESP8266-based boards, like NodeMCU, Huzzah, WeMos D1, Seeed Wio Link, ... can run Blynk directly on the chip, using this board support package: https://github.com/esp8266/Arduino

Tutorials

• Getting started with Blynk: https://learn.sparkfun.com/tutorials/esp8266-thing-development-board-hookup-guide/example-sketch-blink-with-blynk

• Getting started with ESP8266: http://www.esp8266.com/wiki/doku.php?id=getting-started-with-the-esp8266

Troubleshooting

• ESP8266 can't be powered directly from 3v3 pin on most Arduinos, as it requires more than 400 mA current supply. 

• ESP8266 flash might get broken. The code executes without problem right after flashing, but stops working after first reboot.

• This WiFi module can somehow interfere with PIR sensors -> PIR sensor starts producing random values ;)

• ESP8266 currently has troubles with connecting to WPA2-Enterprise networks, and WiFi hotspots that have Captive Portal (webpage that requires you to sign-in to get Internet access).
  

Low level debugging

1. In the IDE switch to Generic ESP8266 board.

2. In setup() add the following as the first line:
       Serial.setDebugOutput(true);

3. In the IDE set Debug port to Serial  and Debug level to All .

You will see a huge amount of debugging information in Serial Monitor.