I recently received two of these shiny new Wifi modules from China and had to test them out. In many posts around the web they say you should use a serial-to-usb adapter to send some AT commands to the module and set it up with your local access point. My problem was: I didn’t have such an adapter, or so I thought. It turns out you can use some types of Arduino’s for the job just fine. I had a Seeeduino V3.0 laying around and that piece of hardware really has a few features built in that I wasn’t aware of before. This is a short explanation on how to setup the Seeeduino to talk to the ESP8266:

1. Upload the following sketch to your Seeeduino:

   void setup()
   {
   pinMode(0,INPUT);
   pinMode(1,INPUT);
   }
   void loop()
   {
   }
   

2. Open the serial console of the Arduino IDE and set the baudrate to 115200
3. Now wire the ESP to your arduino:
   

   ESP8266	Seeeduino
   GND	GND
   VCC+CH_PD	V3.3
   URXD	RX (pin 1)
   UTXD	TX (pin 2)

4. Now send some AT commands for testing (bold is the request, light comments and response):

   AT
   OK
   AT+RST         // resets the module
    ets Jan  8 2013,rst cause:4, boot mode:(3,6)
   
   wdt reset
   [..]
   csum 0xbd
   AT+CWLAP       // lists all access points     
   +CWLAP:(0,"",0)
   +CWLAP:(3,"ap1",-90)
   +CWLAP:(0,"ap2",-87)
   AT+CWJAP="ap1","mypwd"     // join access point ap1 with password mypwd
   OK
   AT+CWJAP?     // show connected access point
   +CWJAP:"ap1"