ESP32-S2 ESPRESSIF ESP32-S2 2.4 GHz Wi-Fi MCU 2.4 GHz Wi-Fi 240 MHz LX7 43 GPIOs

ESPRESSIF ESP32-S2 2.4 GHz Wi-Fi MCU — Overview & Specs

ESPRESSIF ESP32-S2 is a highly integrated, single-core 32-bit Wi-Fi microcontroller SoC built around an Xtensa® LX7 CPU running up to 240 MHz. It combines robust 2.4 GHz IEEE 802.11b/g/n wireless, extensive on-chip peripherals, and advanced security into a compact QFN-56 package—ideal for connected products that must balance performance, power, and cost.

The core platform provides 320 KB SRAM and 128 KB ROM, plus support for external SPI/QSPI/OSPI flash and RAM; certain device options integrate flash and/or PSRAM on-chip. This gives designers flexible memory footprints while maintaining fast code execution via cache acceleration.

For power-sensitive designs, ESP32-S2 delivers ultra-low-power operation through fine-grained clock gating, dynamic voltage and frequency scaling, and a capable ULP (ultra-low-power) coprocessor that can keep sensors, RTC, and GPIO wake sources alive during sleep. Multiple sleep modes—including light-sleep, deep-sleep, and hibernation—help products achieve long battery life without sacrificing responsiveness.

On the I/O side, the SoC exposes 43 programmable GPIOs and a generous peripheral set: SPI (up to four controllers), I2S, I2C, UART, RMT (IR), LED PWM (8 channels), pulse counters, a full-speed USB 2.0 OTG interface with integrated PHY, parallel and serial LCD interfaces, an 8/16-bit DVP camera interface, dual 12-bit SAR ADCs (up to 20 channels), dual 8-bit DACs, 14 capacitive touch channels, and an on-chip temperature sensor.

Security is first-class: secure boot (RSA-PSS), flash encryption (AES-XTS), integrated cryptographic accelerators (AES-128/192/256, SHA-2, RSA), true RNG, HMAC, and a Digital Signature peripheral—features that underpin device identity, firmware integrity, and data confidentiality from factory to field.

The built-in Wi-Fi subsystem supports single-stream 802.11n (20/40 MHz) with data rates up to 150 Mb/s, antenna diversity, and a complete MAC with multiple virtual interfaces for concurrent Station/SoftAP/Promiscuous operation—perfect for provisioning, diagnostics, and peer-to-peer use cases.

Finally, you benefit from a mature SDK (ESP-IDF), cloud connectivity examples, and commonly used “product features” out-of-the-box, which shorten time-to-market for consumer, industrial, and commercial IoT products.

Specifications

Why designers choose ESP32-S2

Fast single-core compute with plenty of headroom. The LX7 at 240 MHz handles UI, protocol stacks, sensor fusion, and DSP-adjacent tasks (via I2S/PCM) while leaving margin for application code. With cache-accelerated XIP and flexible memory mapping, you can scale firmware and assets without sacrificing responsiveness.

Peripheral richness that reduces BOMs. USB OTG eliminates external bridges; the parallel LCD and DVP camera cut display/camera glue logic; 20-channel ADC + 2× DAC + 14 touch pads enable human-machine interfaces and sensing directly on the MCU. TWAI® brings straightforward CAN 2.0 connectivity to industrial devices.

Security built in from day one. Using secure boot and flash encryption anchored in eFuse, you can enforce signed images and at-rest confidentiality. Hardware AES/SHA/RSA accelerators, true RNG, HMAC, and the Digital Signature peripheral give you the tools for secure provisioning, attestation, and TLS performance.

Battery-friendly operations. Light-sleep and deep-sleep currents are optimized, and the ULP can periodically read sensors or touch pads and wake the main core on thresholds—ideal for wearables, e-paper displays, and remote sensors.

ESP32 S2 Applications

ESP32-S2 targets both consumer and industrial IoT scenarios. Typical use cases include:

• Smart home & building: Wi-Fi smart plugs, switches and dimmers with smooth LED dimming; door locks with secure provisioning; lighting panels or thermostats with touch/LCD UIs; energy monitors using multi-channel ADC inputs.

• Human-machine interfaces: USB gadgets, custom keyboards, touch sliders/wheels, and capacitive-touch appliances—combining touch sensing, PWM-driven feedback, and Wi-Fi connectivity.

• Multimedia endpoints: OTT streaming accessories, internet radios, Wi-Fi speakers, and headsets that leverage I2S audio paths and Wi-Fi connectivity.

• Cameras & vision: Compact Wi-Fi cameras or capture devices using the 8/16-bit DVP interface and USB for mass-storage or UVC-style modes (device architecture dependent).

• Industrial & commercial: Wireless sensors, data loggers, and CAN-connected nodes (TWAI®) for factory floors; smart agriculture nodes (greenhouses/irrigation) using low-power sensing and periodic cloud sync.

• Wearables & health: Smart bracelets/watches and monitors that benefit from low-power operation, touch, and secure updates over Wi-Fi.

• Retail & POS: Connected kiosks, POS terminals with LCDs and barcode cameras, and service robots needing reliable Wi-Fi and USB.

• Toys & education: Programmable Wi-Fi toys, remote control devices, proximity-sensing educational kits.

Variant guidance

The ESP32-S2 family spans flash/PSRAM options and temperature capabilities:

• ESP32-S2: baseline device without embedded flash/PSRAM; –40 °C to +105 °C ambient.

• ESP32-S2FH2 / FH4: devices with 2 MB or 4 MB embedded flash; –40 °C to +105 °C ambient.

• ESP32-S2R2: embedded 2 MB PSRAM; –40 °C to +85 °C ambient.

• ESP32-S2FN4R2: embedded 4 MB flash + 2 MB PSRAM; –40 °C to +85 °C ambient.

Use high-temperature “H” flash options for extended ambient ranges (e.g., appliances, light fixtures) and the embedded-PSRAM variants when your UI or buffering needs are higher.

Design notes

• Clocking: the CPU requires an external 40 MHz crystal; audio PLL and internal oscillators service subsystems.

• Power domains: multiple 3.3 V domains plus configurable VDD_SPI (1.8 V via internal LDO or 3.3 V rail). This allows powering down VDD_SPI in deep-sleep to reduce leakage.

• Pin mux: most signals are freely routable via the GPIO matrix—great for PCB flexibility. Note GPIO46 is input-only.

• Radio: typical TX powers meet spectral mask/EVM limits; receiver sensitivities support long-range low-rate as well as higher-throughput modes.