The ESP8266 Breakout, "HUZZAH" from Adafruit (image via Adafruit, in the element14 store)
If you need Wi-Fi connectivity for a project, then the ESP8266 Wi-Fi SoC should be at the top of your list of prospective solutions. They are essentially microcontrollers with wi-fi built in. The module IO pins can be configured for use as all the usual functions like I2C, SPI, ADC, PWM and digital IO.
Just like any other microcontroller you will be able to take data from sensors, control LEDs, and activate relays. Natively, unless the firmware has been changed these devices respond to serially delivered AT/Hayes commands. Anybody who used a modem back in the 1980s will have some familiarity with these. Remember typing in AT DT followed by a phone number?
ESP8266 series of devices isn’t exactly super new. They have been commonly available for several years now but this is a tremendous advantage. Time has allowed for a wealth of knowledge to be built up. Pitfalls and solutions have already been discovered and worked out by your predecessors.
Within the last year, a new Wi-Fi module called the RTL8710 has made an appearance. The RTL8710 and the ESP8266 are very similar and at a glance can be mistaken for each other. I bring up the RTL module because you may mistake it for a relabeled ESP8266, which it is not. Some versions of the RTL module have slightly higher specifications than the ESP counterpart, however, because the RTL is still so new, the level of support and fellow user experience is very sparse. I strongly suggest using ESP8266 modules unless you want to help pave the way into the RTL’s uncharted territory.
With the ESP SOC, you will have that pile of knowledge and fellow user experiences to draw from. Across the interwebs, you can find people who have use these modules as the cornerstones of their projects. There is also an ESP8266 forum. { link http://www.esp8266.com/ }
Something that you will need to be aware of is that there are several iterations of the ESP8266 all with slightly varying specifications and pin assignments.
Wikipedia’s chart of ESP versions.
ESP8266 modules have a pretty unusual footprint and while you can solder wires to the board pads, it is advisable to just get a breakout/motherboard. I have personally destroyed the pads on some of these devices with careless soldering. Also, some of the motherboards come with really handy features like an on-board voltage regulator. This is extremely useful because the ESP8266 modules require 3.3-volts for power.
Arguably, one of the easiest to use versions of the ESP8266 that is already mounted to a motherboard is the very reasonably priced Adafruit Huzzah. ($9.99 at the time of this writing.) The Huzzah has everything you need to get up and running quickly and easily. It’s got a voltage regulator (3-6v power), a reset button, an on-board LED that is already wired to an IO pin and it has a logic level shifter for interfacing to 5-volt devices. It is also has a header on the board for programming via an FTDI cable. Adafruit has a tutorial and best of all, you can load Arduino sketches into the Huzzah. This is extremely convenient because the firmware that comes with the ESPs runs programs written in Lua and I am betting that most people don’t even know what Lua is.
You can get the HAZZAH ESP8266 Breakout from the element14 store, after this link.
Have a story tip? Message me at: cabe(at)element14(dot)com
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