How many ESP32 series currently exist?

Currently, the Espressif ecosystem features 12 primary series: classic ESP32, ESP32-S2, ESP32-S3, ESP32-S31, ESP32-C2, ESP32-C3, ESP32-C5, ESP32-C6, ESP32-C61, ESP32-P4, ESP32-H2, and ESP32-H4.

What are the latest series from Espressif?

The newest series include the ESP32-P4 (high-performance dual-core RISC-V at 400 MHz), the ESP32-C5 (first dual-band 2.4/5 GHz Wi-Fi chip from Espressif), and the ESP32-C61 (cost-effective Wi-Fi 6 and Bluetooth 6).

Xtensa® LX7 single-core 32-bit

ESP32-S2

Focused on security and low power, with native USB and the only ADC with 13-bit output

Official datasheet Programming guide Technical reference manual

Processor: Single-core; Up to 240 MHz
SRAM: 320 KB; + 16 KB RTC SRAM
GPIO: 43; programmable pins
Architecture: Xtensa; Xtensa® LX7 single-core 32-bit

Official development kit

Official Espressif board for the ESP32-S2 series.

Pins with usage restrictions

Not every pin on the ESP32-S2 is free for general-purpose use. 24 of them have conditions: occupied by memory, sampled during boot, or function as input only. Check before finalizing your schematic.

Connected to flash/PSRAM memory

12 pins

SPICS1 · GPIO26
SPIHD · GPIO27
SPIWP · GPIO28
SPICS0 · GPIO29
SPICLK · GPIO30
SPIQ · GPIO31
SPID · GPIO32
GPIO33
GPIO34
GPIO35
GPIO36
GPIO37

Already connected to the memory where firmware is stored and executed. Using them as general-purpose GPIO typically crashes the chip or corrupts execution. In modules with internal flash, they are not brought out to the package pins.

Strapping pins (boot mode)

3 pins

GPIO0
GPIO45
GPIO46

The chip samples the logic level of these pins during reset to determine the boot mode. You can use them after booting, but external circuitry must not force the wrong level during reset, or the board will fail to boot or enter download mode unexpectedly.

Flashing and debugging

6 pins

MTCK · GPIO39
MTDO · GPIO40
MTDI · GPIO41
MTMS · GPIO42
U0TXD · GPIO43
U0RXD · GPIO44

These are the flashing UART and JTAG lines. They can still be used as GPIO, but reusing them removes the ability to flash and debug the board without disconnecting connected peripherals.

Native USB

2 pins

GPIO19
GPIO20

Connected by default to the internal USB Serial/JTAG controller. Using them as GPIO requires disabling this peripheral, which also removes direct USB flashing.

Must not float

1 pin

CHIP_PU

Require a defined hardware logic level: external pull-up or RC delay circuit. Leaving them floating causes random resets or unstable boot behavior.

These groups are derived from the same data as the pinout diagram. There you can see every pin's full functions, power domain, and complete engineering notes.

Open pinout diagram

Processor

Architecture: Xtensa® LX7 single-core 32-bit
Cores: 1 (Single-core)
Frequency: Up to 240 MHz
ULP Coprocessor: Yes (RISC-V)
AI Accelerators: No

Connectivity

Wi-Fi: IEEE 802.11 b/g/n (2.4 GHz, up to 150 Mbps)
Bluetooth: No
Zigbee/Thread: No
Matter: No
Ethernet: No
CAN: No

Tools and availability

Minimum ESP-IDF: v4.2
Arduino Core: Yes (26 board definitions in official core)
Debugging: External JTAG (requires probe, e.g. ESP-PROG)
Package: QFN56 (7×7 mm)
Available Modules: ESP32-S2-MINI-1, ESP32-S2-MINI-2, ESP32-S2-SOLO, ESP32-S2-SOLO-2 and 4 more

Security

AES: AES-128/192/256 with GCM
SHA: SHA-1/224/256/384/512
RSA / MPI: Yes (RSA/MPI up to 4096 bits)
ECC (elliptic curves): No
Hardware ECDSA: No
HMAC: Yes
Digital Signature (DS): Yes
Key Manager: No
Random Generator (TRNG): Yes (hardware TRNG)
Flash Encryption: XTS-AES-128/256
Secure Boot: V2 (RSA-3072)
DPA Protection: No

Memory

SRAM: 320 KB
RTC SRAM: 16 KB
ROM: 128 KB
External Flash: Up to 1 GB via QSPI
External PSRAM: Up to 1 GB via QSPI/Octal SPI

Power consumption

Typical values at 3.3 V and 25 °C. Actual power consumption depends on radio duty cycle and configured clock frequency.

Active (Wi-Fi TX): 160-310 mA
Modem Sleep (CPU 160MHz): 14-24 mA
Light Sleep: 750 µA
Deep Sleep: 20-190 µA

Peripherals

GPIO: 43
ADC: 2x SAR ADC, up to 20 channels: 13-bit output (0–8191, unique in family), 12-bit effective resolution starting from rev v1.0 (errata ADC-112)
DAC: 2x 8-bit DAC
Touch: 14 capacitive channels
UART: 2
SPI: 4 (SPI0/1 for Flash, SPI2/3 for general use)
I2C: 2
I2S: 1
PWM: LED PWM (up to 8 channels)
USB: 1 (USB OTG 1.1 Full-Speed)

Special interfaces

LCD: 8/16-bit LCD interface
Camera: 8/16-bit DVP interface
Temperature Sensor: 1 (internal)

Temperature limits

Operating: -40°C to 105°C
Storage: -40°C to 150°C

Ready to prototype with ESP32-S2?

Explore development boards available for this series, with USB, onboard sensors, and official store links.

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