Features: Full integration on one board: R3 ATmega2560 and WiFi ESP8266 with memory 32Mb (megabyte) All of the modules can work or each separately. And everyone has their own pinout headers The convenient solution for the development of new projects requiring and WiFi Via USB you can sketches and firmvare for ATmega2560 and for ESP8266. For this on board have the USB-serial converter CH340G Use this board is very simple The board has DIP-switch, to connect the modules; For example, to: USB and ATmeg2560, USB and ESP8266, ATmega2560 and ESP8266 Color: black Material: PCB+ plastic+metal Table DIP- Switch: Connection DIP 1 2 3 4 5 6 7 ATmega2560-ESP8266 ON ON OFF OFF OFF OFF OFF USB -ATmega2560 OFF OFF ON ON OFF OFF OFF USB-ESP8266 ( firmware or sketch) OFF OFF OFF OFF ON ON ON USB-ESP8266 (communication) OFF OFF OFF OFF ON ON OFF All OFF OFF OFF OFF OFF OFF OFF solution: USB -- ESP8266 DIP SWITH 2 Connection 1 2 3 4 5 6 7 USB - ATmega2560- ESP8266 ON ON ON ON OFF OFF OFF To RXD3/TXD3 USB converter CH340G connect to RX0/TX0 of ATmega2560 ESP8266 connect to RX3/TX3 of ATmega2560 Size: 10.5x5.3cm/4.13x2.09inch Due to different batches, the silk screen printing of the batch number characters on the product may be different, which does not affect Package Contents: 1 x + WiFi Board Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.