Purchasing ESP8266 on the cheap
Found the ESP8266 module while browsing Arduino parts at http://www.Banggood.com. They sell for $3.48 for 1 and gets cheaper as you buy in quantity. http://www.banggood.com/ESP8266-Remote-Serial-Port-WIFI-Transceiver-Wireless-Module-p-947259.html
I didn’t want to wait the 3-4 week shipping from China so ordered my first one at Amazon with Amazon Prime here for a whopping $7.99: http://www.amazon.com/gp/product/B00O34AGSU/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
One drawback of this module is that there is no documentation that comes with the module. I was prepared for this and was ready to do a lot of Googling and forum hunting to get it working.
Getting first life – finally
I hooked up the ESP8266 to a FTDI TTL-232R-3V3 cable (just a USB to UART cable that has all the UART pins broken out on the end) based on a basic diagram I found here https://nurdspace.nl/File:ESP8266_interface.jpg which showed only VDD, GND, TX and RX…. nothing worked.
Found another diagram with more pins and comment about needing to pull up CH_PD pin here: http://hackaday.io/project/3072/instructions … Basic AT commands started to work after connecting at 10K ohm pull to the CH_PD. Here is the diagram…
Note 1: I am using my Arduino UNO R3 just for the 3.3V supply output at this point. Eventually the ESP8266 will connect to the Arduino UNO R3 board.
Note 2: The Arduino 3.3V supply output current is not rated high enough to support the ESP8266. I am taking my chances with it right now hoping that since my Wifi router is only about 5 feet away, it won’t take too much current.
I gave the AT+GMR command (command list I found here: http://www.electrodragon.com/w/Wi07c) and received a response so have life.
The ESP8266 firmware version that came with my board doesn’t allow for change of baud rate. Eventually I am going to use an Arduino SW UART so need to be able to set the baud to something like 9600.
I found a tool and instruction to update firmware here: http://blog.electrodragon.com/cloud-updating-your-wi07c-esp8266-now/
Ahhhh …. I bricked my ESP8266…. I thought…
After upgrading, I wouldn’t get any AT command responses. I did notice that the ESP8266 would echo everything I typed, so I knew there had to be life. After some Googl’ing, I stumbled on a forum post someplace that the new firmware requires a carriage return (CR) AND line feed (LF). Previous versions only need the CR. I went into menus in TeraTerm and found the setting in the menus under Setup -> Terminal….
Note: Not sure why, but getting junk characters at the start. Maybe the module is sending out serial data before the oscillators are at the correct speeds?