The SparkFun module is the ESP-8266-01 version 2 as far as I can tell. The github esp8266 wiki gives this pin information for the eight pins:
Pins to chip names
Pin Name Description
1 GND Ground
2 U0TXD UART0 Transmit
3 GPIO2 Has internal pull-up
4 CHIP_EN Chip Enable, active high, needs to connect to 3.3 for proper operation
5 GPIO0 Has internal pull-up
6 EXT_RSTB External reset signal, active low, has no pull-up?
7 U0RXD UART0 Receive, has internal pull-up
8 Vdd +3.3V power input
These are the common AT commands as given by multiple sources. In testing, I found it was best to use all capital letters for the commands. Sometimes, lower case would work and others, only capital letters worked.
2. AT+RST-Soft reset
3. AT+GMR-Retrieve firmware version
4. AT+CWMODE-Operation mode selection
5. AT+CWJAP-Join network
6. AT+CWLAP-Available network listing
7. AT+CWQAP-Exit network
8. AT+ CWSAP-Setup network name, password, radio channel and security scheme
9. AT+ CWLIF-Listing connected stations
10. AT+ CIPSTATUS-Connection listing
11. AT+CIPSTART-Initiating connection
12. AT+CIPSEND-Sending data
13. AT+CIPCLOSE-Closing connection
14. AT+CIFSR-Displaying IP from access point
15. AT+CIPMUX-Single or multiple connection selection
16. AT+CIPSERVER-Socket server on/off
17. AT+CIPMODE-Serial port transparent or connecdtion based data output selection
18. AT+CIPSTO-Socket server automatic connection timeout setting
19. +IPD-Serial port connection based data output
At this time, I have used AT, AT+RST, AT+GMR, AT+CWMODE and AT+CWLAP commands. The AT+CWMODE is an important command, AT+CWMODE=1 sets the unit as a station(STA), AT+CWMODE=2 sets the unit as an access point(AP) and AT+CWMODE=3 sets the unit to operate in both modes (either STA or AP). Mode 3 seems the best to use.
The ESP-8266 is a WIFI device and can draw significant amounts of current (over 200 mA). For my testing, I used 3.3/5 volt breadboard power supply (prt-00114) to power the ESP-8266. I also used an inexpensive USB to TTL serial device. I also tried the SparkFun FTDI Basic Breakout 3.3, but it did not work. The funny thing is the USB to TTL serial device is a terrible device to program the standard Arduino boards, but, the SparkFun Basic works great with the Arduino boards.
Here are the five connections that I used for testing:
ESP-8266 Pin To Device
Vdd +3.3V output of the Breadboard Power supply
GND GND of Powersupply. Also the Gnd of the USB to TTL was tied to same GND buss
CHIP_EN +3.3V output of the Breadboard Power supply
U0TXD USB to TTL RX
U0RXD USB to TTL TX
I used the serial monitor tool of the Arduino IDE to send commands and get the ESP-8266 response. The baud rate was 9600 and a carriage return/new line sent with the text command.
The next step for me is to connect the ESP-8266 to an Ardunio Pro-Micro as serial repeater to work out serial communciations between the ESP-8266 and the board. I will also attempt to connect to my home WIFI network. I will post the results under this topic when I get some results.
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