The ESP8266 chipset
The ESP8266 series is produced by Espressif Systems, a fabless semiconductor company operating out of Shanghai, China. The ESP8266 series currently includes the ESP8266EX and ESP8285 chips.
ESP8266EX (referred to simply as ESP8266) is a system-on-chip (SoC) that integrates a 32-bit tensilica microcontroller, standard digital peripheral interfaces, antenna switch, RF balun, power amplifier, low-noise receive amplifier, filter and power management modules into a small package. It provides functions for 2.4 GHz Wi-Fi (802.11 b/g/n, support for WPA/WPA2), general input/output (16 GPIO), Inter-Integrated Circuit (I²C), analog-to-digital conversion (10 -bit ADC), Serial Peripheral Interface (SPI), I²S interfaces with DMA (sharing pins with GPIO), UART (on dedicated pins, plus a transmit-only UART can be enabled on GPIO2) and Pulse Width Modulation (PWM) .
The ESP8266 modules
With this, vendors such as AI-Thinker have created a variety of compact PCB modules around the ESP8266 chip. ESP8266-based modules have proven to be a high-performance, low-cost, and network-ready foundation for supporting end-point IoT developments. Espressif's official modules are currently ESP-WROOM-02 and ESP-WROOM-S2. The AI Thinker modules are succinctly labeled ESP-01 through ESP-14.
