====== setup arduino IDE for ESP8266 ======
  - download the latest [[https://www.arduino.cc/en/Main/Software|Arduino IDE]] and unpack it. 
  - create a subdirectory called ''portable''
  - start your arduino IDE and go to ''File->preferences'' and add this to //Additional Boards Manger URLs//:  ''http://arduino.esp8266.com/stable/package_esp8266com_index.json''
  - select OK and go to ''Tools-Boards...-Boards Manager...'' and enter ''ESP'' into the search. now install the ''esp8266'' module and close that window. 
  - for generic ESP boards verify your settings under Tools are like these: <code>
Board: "Generic ESP8266 Module"  <<<<!!!!
Flash Mode: "DOUT"  <<<<!!!!
Flash Size: "1M (no SPIFFS)"  <<<<!!!!
Debug Port: "Disabled"
Debug Level: "None"
LwIP Variant: "v1.4 Prebuilt" <<<<!!!
Reset Method: "ck"
Crystal Frequency: "26 MHz"
Flash Frequency: "40MHz"
Upload Using: "Serial"
CPU Frequency: "80 MHz"
Upload Speed: "115200"
Port: Your COM port connected to sonoff
</code>
  - for the Wimos D1 mini boards I used these settings (despite mine was called D1 mini and there is also a board setting for the mini, but it didn't upload the sketch when it got bigger than a very small size): <code>
Board: "Wemos D1 R2"
Flash Size: "4M (1M SPIFFS)"
</code> leave the rest to the defaults