WiFi infrastructure is everywhere which makes easier to make network of devices connected to WiFi.
There is also great range of WIFI routers with different space coverage and speeds, and as they are mass produced product the prices are at the rock bottom if we have to compare to Zigbee or Bluetooth.
WiFi stack require resources though and not quite good for smallish 8bit populary hobby processors, this is why UART-to-WIFI solutions were made and become popular.
Texas Instruments released CC3000 which cost about $20-25 in single quantities and $10 in volume.
It took no longer and Chinese company Espressif released their ESP8266 highly integrated UART-WIFI bridge IC, it requires just quartz crystal and balun to make WIFI module, their reference design is with just 11 x 12 mm board space!
And of course this comes at Chinese prices: you can buy ESP8266 module in single quantity from Seedstudio for $6.95 or from Alibaba for $5!
On top of this you can easy connect devices to Internet and send and receive data through UART!
This will definitely wipe out the $50-60 Arduino WIFI shields and even Microchip’s MRF24WB0MA etc modules.
We are going definitely to release MOD-ESP8266 which to connect to all our boards with UEXT and give possibility to connect to Internet with simple AT commands!
With MOD-IO2+MOD-ESP8266 for instance anyone could make WIFI enabled relay and Inputs and monitor through web page the inputs and drive relays for extremly low cost!
olimex 
Aug 28, 2014 @ 08:58:18
Hmm … these chipsets should be supported in the linux kernel too. Otherwise cheap usb based wifi modules seems like better choice for the same price. But potential is big here, especially if Espressif opens their documentation to allow “Integrated low power 32-bit CPU could be used as application processor”
Aug 28, 2014 @ 09:19:17
if you have Linux the route is easy there are very cheap WIFI USB dongles, this one if good for smallish 8bit processors like the AVRs, PICs which have just few KB of RAM and Flash, it hides the WIFI stack with all complexity behind simple AT command set, for EUR 3 you add Internet connectivity to any 8-bit project!
Aug 28, 2014 @ 10:24:20
It also generalises to the AT protocol which means one, simple device driver instead of the confusion of drivers still plaguing Wi-Fi devices. This helps no end with less well-supported executive programs.
Aug 28, 2014 @ 14:51:44
Funny chinese-english story on this page:
http://www.aliexpress.com/item/ESP8266-serial-WIFI-industry-milepost-unbeatable-price-deep-Mingyang-Electronics/2010372971.html
Aug 28, 2014 @ 15:20:53
looks like this one http://www.aietech.com/storage/Translate_server_error.jpg?__SQUARESPACE_CACHEVERSION=1225641636650
using google to translate is not best idea 🙂
Aug 28, 2014 @ 15:24:17
The lack of readable English documentation is going to be a problem – for awhile anyway. But this is quite interesting.
Aug 28, 2014 @ 16:01:10
Translated datasheet: https://nurdspace.nl/ESP8266
Aug 28, 2014 @ 15:59:56
This gives a new life to the Arduino 8bit development for sensors and actuators. The shield WiFi have always been ultra expensive. Olimex why do not do a complete product in the price range of the 10 euro like Arduino Mini Pro (maybe even with the LiPo charger)?
Aug 28, 2014 @ 16:15:09
There are also 6 GPIOs available on the chip itself, probably multiplexed or not with the JTAG port. I wonder what a JTAG scan would give over there.
Aug 28, 2014 @ 16:23:04
This module is really interesting due to its price. I was looking at it a week ago, but not finding much datasheet, but also design example make me turn elsewhere. If Olimex use this thing in a real solution, it will be really appreciated, many IoT designers will start buying them.
Aug 28, 2014 @ 16:34:17
If this chip gets documented and you can actually run code on there with a GCC or something, you won’t need a second chip like an arduino to do something with it. There are 16 GPIOs available on this chip, but they might be multiplexed with other functions, as mentioned on the NURDspace page: “These pins are multiplexed with other functions, such as the main interface, UART, SI, Bluetooth co-existence and so on.”
Aug 28, 2014 @ 21:07:54
English AT commands reference
Aug 28, 2014 @ 21:15:25
I was thinking to use the nRF24LE1 chip (RF + MCU 8051), because it’s cheap and allowed to create a network of small devices for an IOT project, but now with this new chip, the things can be connected directly by wifi.
Aug 28, 2014 @ 22:23:21
Same here. A lot of NRF24 devices in the past. ESP8266 now open WiFi world at the same price. We need better modules, at least with external antenna connector. We are on day 1.
Aug 29, 2014 @ 04:34:57
A new community has emerged for ESP8266 Support…. http://www.esp8266.com, this is going to be a very popular IC and we need all the help we can get figuring it all out! All the docs and code in Chinese 😦
Aug 29, 2014 @ 09:57:09
There is an SDK here:
https://github.com/scottjgibson/esp8266/tree/master/esp_iot_sdk_v0.6/lib
But most of the critical files are blobs, no source code.
Aug 29, 2014 @ 11:59:19
Complete SDK http://bbs.brieflive.com/forum.php?mod=viewthread&tid=2
Aug 31, 2014 @ 14:59:05
The compiler license is expired 😦
Aug 29, 2014 @ 16:31:01
Reading over the source and tools lead me to conclusion that this product uses Tensilica core. I saw mentioning of “xtos” (which is tensilica runtime, “os”) and some “xt-” prefixes. Also, there is a gcc port for Tensilica cores.
Sep 02, 2014 @ 22:29:43
Read this thread – it is possible to build GCC for this chip.
http://www.esp8266.com/viewtopic.php?f=9&t=19