ESP8266 Lolin module

Key Features: Processor: L106 32-bit RISC microprocessor core based on the Tensilica Xtensa Diamond Standard 106Micro running at 80 MHz.
Memory: …
External QSPI flash: up to 16 MiB is supported (512 KiB to 4 MiB typically included)
IEEE 802.11 b/g/n Wi-Fi. …
16 GPIO pins.
SPI.
I?C (software implementation)

Core
– 6T/12T 8051 processor

– Max frequency of 40 MHz

– Operating voltage: 2.4V to 5.5V

– Temperature range: -40? ~ 85?

Memory
– 8 KB of flash memory

– 256B of SRAM

– ISP (In-System Programming)

Connectivity
– One UART