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.
- 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
- 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)