From great enthusiasm, to deep frustration, to a cautious optimism seems the best way to describe the rollercoaster release of the ESP8266 low-cost WiFi transceiver from Shanghai-based Espressif Systems.
At first glance, this device appeared to have it all: Wifi, integrated balun, full TCP/IP stack, great community support, and all at an ultra-low cost……until……
The entrance exam
Shortly after markets were flooded with sub-$5 modules, it was discovered that the device had never passed FCC. Thus the modules that were landing in the US in particular, were coming in without license and in violation of US FCC and customs restrictions (purchased largely from sites like SeeedStudio, p2p via Ebay, and others on Taobao or the like). Now this may jive for hackers willing to skirt the law to save a few bucks, but for professionals and anyone interested in building real products, this was a supreme downer. After all of the effort of getting the devices, getting them working, and getting them integrated into your next great widget, to have your dream crushed by the realities of regulation & “the man”….ugh. Fail.
However recently Espressif announced they had just passed FCC certification for their newer ESP8266EX device which appears to be a slightly more sophisticated part than the previous, non-EX version. Now one might be forgiven for speculating that the revision changed because they’d determined the initial rev simply wouldn’t pass. Perhaps a few tweaks, some updated GPIO capabilities, a new spin of the silicon, a new test board, and voila!
Here you’ll find the link to their FCC documentation including Schematics and PCB files and other various submissions and also a link to the Espressif website. You’ll need an NDA in place to get the full device documentation but anyone serious about using these modules will no doubt be cool running the legal gauntlet for a $3 transceiver with this level of interest and support!