Most common modules ESP-NN seem to come from AI-Thinkers vendor. Espressif Systems themselves have produced the ESP-WROOM-02 Wi-Fi Module.

All Modules by AI-Thinker : see http://wiki.ai-thinker.com/_media/esp8266/esp8266_module_list.png

• 推荐型号 (Green) : Recommended Model
• 停产型号 (Gray) : Discontinued Model

Product Specification : http://wiki.ai-thinker.com/esp8266/docs

User Manual : http://wiki.ai-thinker.com/_media/esp8266/a000um01a3.pdf

There are also modules from other vendors, such as :

• Olimex, see https://www.olimex.com/Products/IoT/,
• Wireless-tag, see http://www.wireless-tag.com/index.php/Product/dis/33.html
• Qilianer, see http://en.qilianer.com/product/28032.html
• Smarttime.cn, see http://www.smartline.com.cn/

and other unknown vendors are starting to become available.

Apparently new versions of older modules are appearing with larger flash sizes. To check the flash size of your module:

• # esptool.py –port /dev/ttyUSB0 –baud 115200 flash_id
• Connecting…
• Manufacturer: c8
• Device: 4013

Then check out the combo at https://code.coreboot.org/p/flashrom/source/tree/HEAD/trunk/flashchips.h:

• manufacturer c8 is GigaDevice and device 4013 is GD25Q40, which is a 4Mbit=512KByte device
• manufacturer ef is Winbond (ex Nexcom) and device 4016 is W25Q32, which is a 32Mbit=4MByte device

CE of ESP-WROOM-02

FCC of ESP-WROOM-02

Note: Some batches of this module ship with LED Current limiting resistors of the wrong value (47Ohm vs 4.7KOhm). This usually results in the power LED vanishing in a puff of smoke.

not FCC approved (*)

Note: some versions have an error on silkscreen: GPIO4 and GPIO5 are exchanged!

not FCC approved (*)

under the can by Baoshi

pinout of current 16 pin variant

pinout shows early 14 pin variant

Notable difference between 14 and 16 pins variants is that 16 pins has LEDs outside shield. Also, antenna socket is on the bottom left, whereas 14-pin has antenna on the top left.

not FCC approved (*)

Two versions of ESP-08 are on the market: one with 7×2 pins (like the one in the picture) and probably a new one with 8×2+ant pins (pinout is the same like the new 8×2 ESP-07)

This does not appear to be the version 11 board picture . Pins are not at the right end

From here

not FCC approved(*)

(*) not FCC approved, just labelled to look like they do, not a valid FCC ID on the label

FCC of ESP-12

FCC ID: 2ADUIESP-12

CE of ESP-12

CE NUMBER: BCTC-141212468

Note:This is not an EU CE declaration of conformity, This is a test pass certificate from a third party test company that has no official standing. An official EU DoC must be made by the manufacturer not a third party. Also note safety standard EN60950 does not exist, and has not for many many years. The R&TTE directive quoted ceased to be valid in 2016. These comments and similar apply to a lot of the certificates on this page.

This reverse engineered schematic wrong in flash connection. Check table below

FLASH SDIO

Please, fix this table if it possible.

The etching on the shield reads: 'STM8S003 INSIDE'

Backside of the ESP8266-14 module. The ESP8266-14 module has pins and connections on three sides of the board

ESP8266-14 module with metal shield removed. Underneath the shield there is a 20-pin QFPN chip with the marking 'S033', which according to the STM8S003 datasheet is the proper device marking.

CE of WT8266-S1

FCC of WT8266-S1

Modules shown here together with an external aerial, a large, cheap and poor quality development board together with a small, expensive and high quality development board.

× New firmwares can only be flashed on boards with at least 1MB (8Mb) flash. ×× May be different on different editions of the board. ××× Antenna connector is connected by default, to use PCB antenna switch (solder) the 0Ω resistor to the corresponding position.

more products : http://wiki.ai-thinker.com/_media/esp8266/esp8266_module_list.png