The ESP8266 is a low-cost Wi-Fi microchip, with a full TCP/IP stack and microcontroller capability, produced by Espressif Systems[1] in Shanghai, China.
ESP8266
ESP-01 module by Ai-Thinker with ESP8266EX SoC
Manufacturer
Espressif Systems
Type
32-bit microcontroller
CPU
Tensilica Diamond Standard 106Micro (aka. L106) @ 80 MHz (default) or 160 MHz
Memory
32 KiB instruction, 80 KiB user data
Input
16 GPIO pins
Power
3.3 V DC
Successor
ESP32
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 first, there was almost no English-language documentation on the chip and the commands it accepted.[2] The very low price and the fact that there were very few external components on the module, which suggested that it could eventually be very inexpensive in volume, attracted many hackers to explore the module, the chip, and the software on it, as well as to translate the Chinese documentation.[3]
The ESP8285 is an ESP8266 with 1 MiB of built-in flash, allowing the building of single-chip devices capable of connecting to Wi-Fi.[4]
These microcontroller chips have been succeeded by the ESP32 family of devices, including the pin-compatible ESP32-C3.
Processor: L106 32-bit RISC microprocessor core based on the Tensilica Xtensa Diamond Standard 106Micro running at 80 MHz[5]
Memory:32 KiB instruction RAM
32 KiB instruction cache RAM
80 KiB user-data RAM
16 KiB ETS system-data RAM
External QSPI flash: up to 16 MiB is supported (512 KiB to 4 MiB typically included)
IEEE 802.11 b/g/n Wi-FiIntegrated TR switch, balun, LNA, power amplifier and matching network
WEP or WPA/WPA2 authentication, or open networks
16 GPIO pins
SPI
I²C (software implementation)[6]
I²S interfaces with DMA (sharing pins with GPIO)
UART on dedicated pins, plus a transmit-only UART can be enabled on GPIO2
The reason for the popularity of many of these boards over the earlier ESP-xx modules is the inclusion of an on-board USB-to-UART bridge (like the Silicon Labs' CP2102 or the WCH CH340G) and a Micro-USB connector, coupled with a 3.3-volt regulator to provide both power to the board and connectivity to the host (software development) computer – commonly referred to as the console, making it an easy development platform. With earlier ESP-xx modules, these two items (the USB-to-serial adapter and the regulator) had to be purchased separately and be wired into the ESP-xx circuit. Modern ESP8266 boards like the NodeMCU are easier to work with and offer more GPIO pins. Most of the boards listed here are based on the ESP-12E module, but new modules are being introduced seemingly every few months.
Name
Active pins
Pitch
Form factor
LEDs
Antenna
Shielded
Dimensions (mm)
Notes
Bolt IoT
14
0.1 in
2×14 DIL
Yes
PCB trace
Yes
30 × 40
Comes with an onboard SD card and features like Lib-Discovery and Fail Safe Mode. Has its own cloud for IoT.
Olimex MOD-WIFI-ESP8266[21]
2
0.1 in
UEXT module
Yes
PCB trace
No
?
Only RX/TX are connected to UEXT connector.
Olimex MOD-WIFI-ESP8266-DEV[22]
20
0.1 in
2×11 DIL + castellated
Yes
PCB trace
No
33 × 23
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 in
2×15 DIL
Yes
PCB trace
Yes
49 × 24.5
Uses the ESP-12 module; includes USB to serial interface.
Adafruit Huzzah ESP8266 breakout[23]
14
0.1 in
2×10 DIL
Yes
PCB trace
Yes
25 × 38
Uses the ESP-12 module.
SparkFun ESP8266 Thing[24] WRL-13231
12
0.1 in
2×10 DIL
Yes
PCB trace + U.FL socket
No
58 × 26
FTDI serial header, Micro-USB socket for power, includes Li-ion battery charger.
KNEWRON Technologies smartWIFI[25]
12
0.1 in
2×20 DIL
Yes 1 RGB
PCB trace
Yes
25.4 × 50.8
CP2102 USB bridge, includes battery charger, micro-USB socket for power and battery charging, 1 RGB LED and USER / Reflash button.
ArduCAM ESP8266 UNO[26]
12+
0.1 in
Arduino Uno
Yes
PCB trace
Yes
53.4 × 68.6
Uses the AI Thinker's ESP8266MOD module and features Micro-USB port, Battery pins, Camera pins and uSD card all on the same board. Fully compatible with Arduino Uno shields.
DoIT ESPduino[27]
12
0.1 in
Arduino Uno
Yes
PCB trace
Yes
53.4 × 68.6
Uses the ESP-WROOM-02 (ESP-13) module and USB Type B port. Fully compatible with Arduino Uno shields.
WeatherPlus - SwitchDoc Labs[28]
26+Grove
0.1 in
Custom
Yes
PCB trace
Yes
86.0 × 50.0
Uses the AI Thinker Model ESP8266MOD (ESP-13) module and FTDI for Programming and Mini-USB port for power. Fully compatible with Adafruit Huzzah software. Includes BMP280 Barometer, ADS1115 and Grove I2C connectors. Plugs for Anemometer/Wind Vane/Rain Bucket.
WeMos[29] D1[30]
12
0.1 in
Arduino Uno
Yes
PCB trace
Yes
53.4 × 68.6
Uses the ESP-12F module and Micro-USB socket. Discontinued in favor of WeMos D1 R2.
WeMos[29] D1 R2[31]
12
0.1 in
Arduino Uno
Yes
PCB trace
Yes
53.4 × 68.6
Uses ESP-12F module and has Micro-USB socket.
WeMos[29] D1 mini[32]
12
0.1 in
2×8 DIL
Yes
PCB trace
Yes
25.6 × 34.2
Uses ESP-12S module and has Micro-USB socket.
WeMos[29] D1 mini Lite[33]
12
0.1 in
2×8 DIL
Yes
PCB trace
Yes
25.6 × 34.2
Based on the ESP8285, an ESP8266 with 1 MiB flash built-in; has Micro-USB socket.
WeMos[29] D1 mini Pro[34]
12
0.1 in
2×8 DIL
Yes
Ceramic and U.FL socket
Yes
25.6 × 34.2
Uses ESP8266EX chip; has Micro-USB socket, U.FL antenna connector, and 16 MiB flash.
ESPert ESPresso Lite[35]
16
0.1 in
2×8 DIL
Yes
PCB trace
Yes
26.5 × 57.6
Uses the ESP-WROOM-02 module. Produced in limited quantity as beta version.
ESPert ESPresso Lite V2.0[36]
24
0.1 in
2×10 DIL
Yes
PCB trace
Yes
28 × 61
Improved version of ESPresso Lite.
In-Circuit ESP-ADC[37]
18
0.1 in
2×9 DIL
No
U.FL socket
Yes
22.9 × 14.9
Uses ESP8266EX chip.
Watterott ESP-WROOM02-Breakout[38]
14
0.1 in
2×10 DIL
Yes
PCB trace
Yes
40.64 × 27.94
Uses the Espressif ESP-WROOM-02 module.
Geek Wave Solution IOT WROOM-02 Dev. Board[39]
20
0.1 in
?
Yes
PCB trace
Yes
93.80 × 80.02
Development board with Espressif ESP-WROOM-02 module and four relays.
Witty 2-piece board[40]
20
0.1 in
?
Yes
PCB trace
Yes
?
Development board with Espressif ESP8266 ESP-12E and separate board for CH340G USB interface.
ESP32-C3
See also
References
External links