The ESP32-S2-SOLO-N4R2 is a single-core WiFi module from the ESP32 series, built around the ESP32-S2R2 IC. It integrates a 2.4 GHz 802.11b/g/n radio with a data rate of 150 Mbps, a PCB trace antenna plus an IPEX connector for an external antenna, and a 40-SMD module package for surface-mount reflow assembly.
With 4 MB flash and 2 MB PSRAM on-chip, plus 128 kB ROM and 336 kB SRAM, this module handles larger application images and data buffers than the base ESP32-S2 — the PSRAM is useful for frame buffers in camera or display applications, or for TLS session data in secure IoT endpoints. The serial interface set includes ADC, GPIO, I²C, I²S, SPI, PWM, UART, and USB — enough to connect sensors, displays, audio codecs, and external flash without a separate host MCU. The USB peripheral enables direct programming and CDC-ACM virtual COM port for debug or data streaming.
RF link budget and power supply planning
Transmit power is 19.5 dBm, and receive sensitivity hits -97 dBm — a link budget of roughly 116 dB at the lowest data rate, which in open air translates to several hundred metres of range. The 71–75 mA receive current and 165–310 mA transmit current mean the 3.0–3.6 V supply rail must deliver peaks near 1.1 W during a TX burst; a local LDO or DC-DC with at least 400 mA headroom keeps the rail from drooping. The module is not AEC-Q100 graded, so it is not qualified for under-hood or powertrain applications.