ESP8266 WiFi module

ESP8266 Resources

Electrodragon (recommended for updating firmware)

Handy Tables

The freaking hidden github that takes an hour to find with the compiled latest firmware (inside AT)

Some interesting uses

WiFi Meat Thermometer

Brew Monitor

Terrible Browser

LED dimmer

ESP8266 as a webserver

another server

Connecting To Arduino

The consensus seems to be that these are best powered with either a separate 3.3 V supply capable of at least 200 mA, or failing that 3V3 LDO from the 5V line, need level conversion on the digital IO, and at least CH_PD and RST (maybe also GPIO0/2) should be pulled up to VCC.

200 mA is not nearly enough for peak current draws. If you have a 3.3V supply that small, I would have a giant decoupling capacitor, in the hundreds of uF range. I would recommend at least 500 mA and ideally 1 A with plenty of decoupling. The 3.3V regulator on the Seeeduino can supply this. --Guan (talk) 18:49, 7 November 2014 (UTC)

I had success using the ChipKit Uno32, which provides 425 mA on 3V3, has 3V3 digital IO and even has two hardware serial ports, which is very handy, as software serial is limited to 19200 bps, and older firmware defaults to 57600 or 115200 bps.

Here is some example code for the Uno32 with ESP8266 and the Basic IO Shield

A firmware upgrade to at least 0.9.2.2 improves stability, defaults baud rate to 9600, and allows control of baud rate. With the 0.9.2.2 firmware you need to send newline+CR after each command.

The module puts out a number of different error messages. This seems to happen more often in crowded networks. Resetting the module on errors by pulling either RESET or CH_PD low for a short period is a possible work-around.

esp8266 forum Arduino thread

Mega2560 Hardware UART

Another Mega UART

Pins etc