The ESP8266 ESP–01 is a low-cost Wi-Fi module with full TCP/IP stack and microcontroller capability, that allows microcontrollers like arduino access to a Wi-Fi network. You can give a microcontroller internet access like a Wi-Fi shield for Arduino, or you can program the ESP8266 to act as a microcontroller with WiFi connectivity as well. Features Processor: L106 32-bit RISC microprocessor core based on the Tensilica Xtensa Diamond Standard 106Micro running at 80 MHz External QSPI flash: up to 16 MiB is supported (512 KiB to 4 MiB typically included) 16 GPIO pins SPI I²C (software implementation) I²S interfaces with DMA (sharing pins with GPIO) UART on dedicated pins, plus a transmit-only UART can be enabled on GPIO2 10-bit ADC (successive approximation ADC)
