ESP8266
The ESP8266 is a low-cost Wi-Fi chip with full TCP/IP stack and microcontroller capability produced by Shanghai-based Chinese manufacturer, Espressif.
The chip first came to the attention of western makers in August 2014 with the ESP-01 module, made by a third-party manufacturer, AI-Thinker. This small module allows microcontrollers to connect to a Wi-Fi network and make simple TCP/IP connections using Hayes-style commands. However, at the time there was almost no English-language documentation on the chip and the commands it accepted.[1] The very low price and the fact that there were very little external components on the module which suggests that it could eventually be very inexpensive in volume, attracted many hackers to explore the module, chip, and the software on it, as well as to translate the Chinese documentation.[2]
Features
- 32-bit RISC CPU: Tensilica Xtensa LX106 running at 80 MHz
- 64 KiB of instruction RAM, 96 KiB of data RAM
- External QSPI flash - 512 KiB to 4 MiB (up to 16MiB is supported)
- IEEE 802.11 b/g/n Wi-Fi
- Integrated TR switch, balun, LNA, power amplifier and matching network
- WEP or WPA/WPA2 authentication, or open networks
- 16 GPIO pins
- SPI, I²C,
- I²S interfaces with DMA (sharing pins with GPIO)
- UART on dedicated pins, plus a transmit-only UART can be enabled on GPIO2
- 1 10-bit ADC
SDKs
In late October 2014, Espressif released a software development kit (SDK) that allowed the chip to be programmed, removing the need for a separate microcontroller.[3] Since then, there have been many official SDK releases from Espressif; Espressif maintains two versions of the SDK — one that is based on RTOS and the other based on callbacks.[4]
An alternative to Espressif's official SDK is the open source esp-open-sdk[5] that is based on the GCC toolchain. ESP8266 uses the Cadence Tensilica LX106 microcontroller and the GCC toolchain is open-sourced and maintained by Max Filippov.[6] Another alternative is "Unofficial Development Kit" by Mikhail Grigorev.[7][8]
It can also be programmed with the help of NodeMCU.
Espressif modules[9]
This is the series of ESP8266-based modules made by Espressif.
| Name | Active pins | Pitch | Form factor | LEDs | Antenna | Shielded? | Dimensions (mm) | Notes |
|---|---|---|---|---|---|---|---|---|
| Espressif Espressif WROOM-02[10] | 18 | 0.1“ | 2×9 DIL | No | PCB trace | Yes | 18 × 20 | FCC ID 2AC7Z-ESPWROOM02 |
AI-Thinker modules[11]
These were the first series of modules made by third-party manufacturer, AI-Thinker with the ESP8266 and remain the most widely available.
| Name | Active pins | Pitch | Form factor | LEDs | Antenna | Shielded? | dimensions (mm) | Notes |
|---|---|---|---|---|---|---|---|---|
| ESP-01 | 6 | 0.1“ | 2×4 DIL | Yes | PCB trace | No | 14.3 × 24.8 | |
| ESP-02 | 6 | 0.1” | 2×4 castellated | No | U-FL connector | No | 14.2 × 14.2 | |
| ESP-03 | 10 | 2 mm | 2×7 castellated | No | Ceramic | No | 17.3 × 12.1 | |
| ESP-04 | 10 | 2 mm | 2×4 castellated | No | None | No | 14.7 × 12.1 | |
| ESP-05 | 3 | 0.1“ | 1×5 SIL | No | U-FL connector | No | 14.2 × 14.2 | |
| ESP-06 | 11 | misc | 4×3 dice | No | None | Yes | 14.2 × 14.7 | Not FCC approved |
| ESP-07 | 14 | 2 mm | 2×8 pinhole | Yes | Ceramic + U-FL connector | Yes | 20.0 × 16.0 | Not FCC approved |
| ESP-08 | 10 | 2 mm | 2×7 castellated | No | None | Yes | 17.0 × 16.0 | Not FCC approved |
| ESP-09 | 10 | misc | 4×3 dice | No | None | No | 10.0 × 10.0 | |
| ESP-10 | 3 | 2 mm? | 1×5 castellated | No | None | No | 14.2 × 10.0 | |
| ESP-11 | 6 | 0.05” | 1×8 pinhole | No | Ceramic | No | 17.3 × 12.1 | |
| ESP-12 | 14 | 2 mm | 2×8 castellated | Yes | PCB trace | Yes | 24.0 × 16.0 | FCC and CE approved[12] |
| ESP-12-E | 20 | 2 mm | 2×8 castellated | Yes | PCB trace | Yes | 24.0 × 16.0 | |
| ESP-12-F | 20 | 2 mm | 2×8 castellated | Yes | PCB trace | Yes | 24.0 × 16.0 | FCC and CE approved. Improved antenna performance. 4MB Flash |
| ESP-13 | 16 | 1.5 mm | 2×9 castellated | No | PCB trace | Yes | W18.0 x L20.0 | Marked as ″FCC″. Shielded module is placed sideways, as compared to the ESP-12 modules. |
| ESP-14 | 22 | 2 mm | 2×8 castellated +6 | No | PCB trace | Yes | 24.3 x 16.2 |
Other boards
| Name | Active pins | Pitch | Form factor | LEDs | Antenna | Shielded? | dimensions (mm) | Notes |
|---|---|---|---|---|---|---|---|---|
| Olimex MOD-WIFI-ESP8266[13] | 2 | 0.1“ | UEXT module | Yes | PCB trace | No | ? | Only RX/TX are connected to UEXT connector |
| Olimex MOD-WIFI-ESP8266-DEV[14] | 20 | 0.1“ | 2×11 DIL + castellated | Yes | PCB trace | No | ? | All available GPIO pins are connected, also has pads for soldering UEXT connector (with RX/TX and SDA/SCL signals) |
| NodeMCU DEVKIT | 14 | 0.1“ | 2×15 DIL | Yes | PCB trace | Yes | ? | Uses the ESP-12 module, includes USB serial interface |
| Adafruit Huzzah ESP8266 breakout[15] | 14 | 0.1“ | 2×10 DIL | Yes | PCB trace | Yes | 25 × 38 | Uses the ESP-12 module |
| SparkFun ESP8266 Thing[16] WRL-13231 | 12 | 0.1“ | 2×10 DIL | Yes | PCB trace + U.FL socket | No | 58 x 26 | FTDI serial header, Micro-USB socket for power, includes Li-ion battery charger |
| KNEWRON Technologies smartWIFI[17] | 12 | 0.1“ | 2×20 DIL | Yes 1 RGB | PCB trace | Yes | 25.4 x 50.8 | CP2102 USB bridge, includes battery charger, micro-USB socket for power and battery charging, 1 RGB LED and USER / Reflash button |
| WeMos D1[18] | 12 | 0.1“ | Arduino Uno | Yes | PCB trace | Yes | 53.4 × 68.6 | Uses the ESP-12F module, Micro-USB socket |
| WeMos D1 R2[19] | 12 | 0.1“ | Arduino Uno | Yes | PCB trace | Yes | 53.4 × 68.6 | Uses the ESP-12F module, Micro-USB socket |
| WeMos D1 Mini[20] | 12 | 0.1“ | 2×8 DIL | Yes | PCB trace | Yes | 25.6 × 34.2 | Uses the ESP-12F module, Micro-USB socket |
| ESPert ESPresso Lite[21] | 16 | 0.1" | 2x8 DIL | Yes | PCB trace | Yes | 26.5 x 57.6 | Uses the WROOM-02 module. Produced in limited quantity as beta version. |
| ESPert ESPresso Lite V2.0[22] | 24 | 0.1" | 2x10 DIL | Yes | PCB trace | Yes | 28 x 61 | Improved design and feature to ESPresso Lite. |
| In-Circuit ESP-ADC[23] | 18 | 0.1" | 2x9 DIL | No | U.FL socket | No | 22.9 x 14.9 | Uses the ESP8266EX |
References
- ^ Brian Benchoff (August 26, 2014). "New Chip Alert: The ESP8266 WiFi Module (It's $5)". hackaday. Retrieved 2015-06-24.
- ^ Brian Benchoff (September 6, 2014). "The Current State of ESP8266 Development". hackaday. Retrieved 2015-06-24.
- ^ Brian Benchoff (October 25, 2014). "An SDK for the ESP8266 WiFi Chip". hackaday. Retrieved 2015-06-24.
- ^ Espressif Systems (July 29, 2015). "Official SDK release from Espressif for ESP8266". Espressif. Retrieved 2015-08-08.
- ^ https://github.com/pfalcon/esp-open-sdk
- ^ Max Filippov (Feb 15, 2015). "ESP8266 GCC Toolchain". Retrieved 2015-08-08.
- ^ https://github.com/CHERTS/esp8266-devkit>
- ^ http://programs74.ru/udkew-en.html
- ^ "ESP8266 | Espressif 乐鑫". espressif.com. Retrieved 2016-02-10.
- ^ "Espressif WROOM-02". Espressif. Retrieved 2015-07-29.
- ^ "ESP8266 module family". esp8266.com wiki. Retrieved 2015-06-24.
- ^ "2ADUIESP-12 by Shenzhen Anxinke technology co., LTD for WIFI Module". FCC. December 30, 2014. Retrieved 2015-06-24.
- ^ "MOD-WIFI-ESP8266". Olimex. Retrieved 2015-06-25.
- ^ "MOD-WIFI-ESP8266-DEV". Olimex. Retrieved 2015-06-25.
- ^ "Adafruit HUZZAH ESP8266 Breakout". Adafruit Industries. Retrieved 2015-06-25.
- ^ "SparkFun ESP8266 Thing". SparkFun. Retrieved 2015-06-27.
- ^ "KNEWRON smartWIFI". KNEWRON. Retrieved 2016-03-04.
- ^ "WeMos D1". WeMos. Retrieved 2016-01-05.
- ^ "WeMos D1 R2". WeMos. Retrieved 2016-01-05.
- ^ "WeMos D1 Mini". WeMos. Retrieved 2016-01-05.
- ^ "Espert". Espert. Retrieved 2016-01-07.
- ^ "Cytron Technologies - ESPresso Lite V2.0". www.cytron.com.my. Retrieved 2016-02-10.
- ^ "ESP-ADC DIL18 development board". In-Circuit Wiki. Retrieved 2016-02-03.
External links
- BBS.espressif.com - Espressif's Forum with complete documentations on the ESP8266
- ESP8266.com - community forum
- SUPLA - Open source building automation system based on ESP8266
- WiFi-IoT - universal firmware WEB-builder from Maxim Miklin. The firmware is written in pure C language.
