WiFi MCU with integrated memory and radio
The ESP32-S2FN4R2 is a single-core WiFi microcontroller from the ESP32 series, built around the ESP32-S2 core. It integrates a 2.4 GHz radio supporting 802.11b/g/n at up to 150 Mbps, with a transmit power of 19.5 dBm and a receive sensitivity of -97 dBm — enough link budget for a reliable connection through a couple of interior walls in a typical home or light-industrial setting. On-chip memory comprises 128 kB ROM and 320 kB SRAM, which handles moderate application code and data buffers without an external memory chip for many IoT endpoints. The 56-VFQFN exposed-pad package (0.5 mm pitch) is hand-solderable with a fine-tip iron and a hot-air station — a maker-friendly footprint that also suits automated assembly.
Supply, temperature, and interface set
Serial interfaces include ADC, GPIO, I²C, I²S, SPI, PWM, UART, and USB, covering the common peripheral mix for sensor fusion, audio playback, display control, and wired debug. The USB interface doubles as a programming and serial-console port, eliminating the need for a separate USB-UART bridge on the board. Current draw is 63–68 mA in receive mode and 160–310 mA during transmit, depending on the output power setting. The 310 mA peak occurs at the 19.5 dBm max output — a 3.3 V rail feeding this part should budget at least 1.2 W for the radio burst, plus margin for the rest of the system.