ESP8266 WiFi Serial Transceiver Module - 1MB Flash

 This ESP8266 Serial WIFI Transceiver Module is a self-contained SOC with integrated TCP/IP protocol stack that can give any microcontroller access to your WiFi network. The ESP8266 is capable of either hosting an application or offloading all Wi-Fi networking functions from another application processor.

Connection to micro:bit - Thinkspeak

https://makecode.microbit.org/pkg/alankrantas/pxt-ESP8266_ThingSpeak

Key Features 

• Perfect choice for wifi enabled iot projects 
• Abundant community resources around ESP8266
• Upgrade 1M Flash
• High degree of on-chip integration 
• Powerful on-board processing and storage capacities

Description

The ESP8266 Serial WIFI Wireless Transceiver Module is a system on a chip (SOC) Wi-Fi microchip for Internet of Things (IoT) applications produced by Espressif Systems.

The ESP8266 module enables microcontrollers to connect to 2.4 GHz Wi-Fi, using IEEE 802.11 bgn. It can be used with ESP-AT firmware to provide Wi-Fi connectivity to external host MCUs, or it can be used as a self-sufficient MCU by running an SDK. The module has a full TCP/IP stack and provides the ability for data processing, reads and controls of GPIOs.

Given its low cost, small size and adaptability with embedded devices, the ESP8266 is now used extensively across IoT devices. It is always a popular choice for IoT developers and manufacturers. 

It has many GPIOs. With the help of  a SDK and various libraries, you can build your own firmware and use these GPIOs as arduino pins, and it makes external microcontrollers unnecessary.