D1 Mini ESP8266 Dev Board

ESP8266 WiFi development board compatible with the Arduino IDE and with NodeMCU.
Breadboard-compatible.
11 digital and one analogue I/O.
The I/O pins support interrupt, PWM, I2C, and one-wire, except for D0.
Supplied with three different sets of header pins.
Programmed and powered via the on-board micro-USB connector and CH340 (UART) converter.
Dimensions: 34 x 25.5 x 7mm.

Pinout:
TX TXD
RX RXD
A0 Analog input
D0 I/O
D1 I/O, SCL
D2 I/O, SDA
D3 I/O, 10k pull-up
D4 I/O, 10k pull-up, BUILTIN_LED
D5 I/O, SCK
D6 I/O, MISO
D7 I/O, MOSI
D8 I/O, 10k pull-down, SS
G Ground
5V 5V
3V3 3.3V
RST Reset

Prototyping shield also available - see PCB013.