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® LX6 dual-core 32-bit

ESP32

The original model with dual-core processor and wide range of peripherals

Official datasheet Programming guide Technical reference manual

Processor: Dual-core; Up to 240 MHz
SRAM: 520 KB; + 16 KB (divided into RTC FAST and RTC SLOW) RTC SRAM
GPIO: 34; programmable pins
Architecture: Xtensa; Xtensa® LX6 dual-core 32-bit

Official development kit

Official Espressif board for the ESP32 series.

Pins with usage restrictions

Not every pin on the ESP32 is free for general-purpose use. 17 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

8 pins

GPIO16
GPIO17
SD_DATA_2 · GPIO9
SD_DATA_3 · GPIO10
SD_CMD · GPIO11
SD_CLK · GPIO6
SD_DATA_0 · GPIO7
SD_DATA_1 · GPIO8

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)

4 pins

MTDI · GPIO12
MTDO · GPIO15
GPIO2
GPIO0

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

MTMS · GPIO14
MTDI · GPIO12
MTCK · GPIO13
MTDO · GPIO15
U0RXD · GPIO3
U0TXD · GPIO1

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.

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® LX6 dual-core 32-bit
Cores: 1 (Single-core) or 2 (Dual-core)
Frequency: Up to 240 MHz
ULP Coprocessor: Yes
AI Accelerators: No

Connectivity

Wi-Fi: IEEE 802.11 b/g/n (2.4 GHz, up to 150 Mbps)
Bluetooth: Bluetooth 4.2 BR/EDR (Classic) and Bluetooth LE (dual mode)
Zigbee/Thread: No
Matter: No
Ethernet: Yes (Integrated Ethernet MAC)
CAN: 1 (CAN 2.0, TWAI®)

Tools and availability

Minimum ESP-IDF: Since initial release (v3.x and earlier)
Arduino Core: Yes (147 board definitions in official core)
Debugging: External JTAG (requires probe, e.g. ESP-PROG)
Package: QFN48 (6×6 mm) and QFN48 (5×5 mm)
Available Modules: ESP32-MINI-1, ESP32-PICO-MINI-02, ESP32-PICO-V3, ESP32-PICO-V3-02 and 11 more

Security

AES: AES-128/192/256
SHA: SHA-1/256/384/512
RSA / MPI: Yes (RSA/MPI up to 4096 bits)
ECC (elliptic curves): No
Hardware ECDSA: No
HMAC: No
Digital Signature (DS): No
Key Manager: No
Random Generator (TRNG): Yes (hardware TRNG)
Flash Encryption: Yes (AES-256, legacy scheme)
Secure Boot: V1 (AES, legacy); V2 (RSA-3072, RSA-PSS) starting from rev v3.0 (ECO3)
DPA Protection: No

Memory

SRAM: 520 KB
RTC SRAM: 16 KB (divided into RTC FAST and RTC SLOW)
ROM: 448 KB (for boot and core functions)
External Flash: Up to 16 MB via QSPI
External PSRAM: Up to 8 MB via QSPI (in specific modules such as WROVER)

Power consumption

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

Active (CPU 240MHz): 30-68 mA
Active (Wi-Fi TX): 180-240 mA
Modem Sleep: 20-44 mA
Light Sleep: 0.8 mA
Deep Sleep: 10-150 µA
Hibernation: 5 µA

Peripherals

GPIO: 34
ADC: 2x 12-bit SAR ADC, up to 18 channels
DAC: 2x 8-bit DAC
Touch: 10 capacitive channels
UART: 3
SPI: 4 (SPI, HSPI, VSPI - 2 can be used for Flash/PSRAM)
I2C: 2
I2S: 2
PWM: LED PWM (up to 16 channels), Motor PWM
USB: No

Special interfaces

SDIO: 1 (SD/SDIO/MMC Host), 1 (SDIO/SPI Slave)
Hall Sensor: 1 (internal)
Temperature Sensor: No (removed from datasheet in 2018; no driver in ESP-IDF)

Temperature limits

Operating: -40°C to 125°C
Storage: -40°C to 150°C

Ready to prototype with ESP32?

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

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