ODSEVEN ESP8266 STM Module ESP-12 Mini WiFi Development Board Micro USB 3.3V for Raspberry Pi
Add Internet to your next project with an adorable, bite-sized WiFi microcontroller, at a price you like! The ESP8266 processor from Espressif is an 80 MHz microcontroller with a full WiFi front-end (both as client and access point) and TCP/IP stack with DNS support as well. We do sell these on a breakout, but maybe you wanna just put this in your own project PCB.
This is D1 mini, it is a mini WIFI board based on ESP-8266EX.
11 digital input/output pins, all pins have interrupt/pwm/I2C/one-wire
1 analog input(3.3V max input)
a Micro USB connection