esp32 Development Boards

The list of esp32 development boards, complete with pinouts, technical specifications, datasheets and more.

The ESP32 is a powerful dual-core Wi-Fi and Bluetooth microcontroller ideal for a wide range of IoT applications. With its fast processing, low-power modes, and extensive GPIO capabilities, it is widely used in smart home devices, wearables, robotics, and sensor networks.

It supports Bluetooth Classic and BLE, along with 802.11 b/g/n Wi-Fi. Developers can use the Arduino IDE, ESP-IDF, or MicroPython. Common variants include the ESP32-WROOM-32 and ESP32-WROVER (with PSRAM).

Technical Specifications

Microcontroller

Microcontroller Xtensa dual-core 32-bit LX6

Frequency Up to 240 MHz

Connectivity

WiFi 802.11 b/g/n (2.4 GHz)

Bluetooth 4.2

BLE 4.2

Interfaces

Analog-Digital Converter (ADC) Two 12-bit, 18 Channels

Digital-Analog Converter (DAC) Two 8-bit Channels

SPI 4

I2C 2

I2S 2

RMT 8 Channels

Touch Sensor Pins 10

View Datasheet

Strapping Pins

Some pins are reserved for critical functions like bootstrapping, JTAG debugging, USB communication, and flash memory operations. Misusing these pins may lead to boot failures, programming issues, USB conflicts, or disruptions in flash storage.

Critical Pin Categories:

Strapping Pins: Control boot behavior and flash voltage selection
JTAG Debugging Pins: Required for low-level debugging
USB Communication Pins: Used for USB Serial/JTAG communication
Flash Memory & SPI Pins: Connected to SPI flash memory and PSRAM
UART Serial Communication Pins: Used for debugging and firmware uploads

PIN	Label	Reason	Function
IO0	GPIO0	Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.	🛠️ Strapping
IO1	U0TXD (GPIO1)	Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.	🔌 USB
IO2	GPIO2	If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.	🛠️ Strapping
IO3	U0RXD (GPIO3)	Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.	🔌 USB
IO4	GPIO4	Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).	🛠️ Strapping
IO5	GPIO5	Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.	🛠️ Strapping
IO6	GPIO6 (Flash SCK)	Used for internal flash/PSRAM communication; not available for general GPIO.	⚡ Flash
IO7	GPIO7 (Flash SD0)	Used for internal flash/PSRAM data; not available for general GPIO.	⚡ Flash
IO8	GPIO8 (Flash SD1)	Used for internal flash/PSRAM data; not available for general GPIO.	⚡ Flash
IO9	GPIO9 (Flash SD2)	Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.	⚡ Flash
IO10	GPIO10 (Flash SD3)	Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.	⚡ Flash
IO11	GPIO11 (Flash CMD)	Used by internal flash (chip select/command); not available for general use.	⚡ Flash
IO12	MTDI (GPIO12)	Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.	🛠️ Strapping
IO13	MTCK (GPIO13)	Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.	🪛 Other
IO14	MTMS (GPIO14)	Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.	🪛 Other
IO15	MTDO (GPIO15)	Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.	🛠️ Strapping
IO16	GPIO16	Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.	⚡ Flash
IO17	GPIO17	Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.	⚡ Flash
IO34	GPIO34	Cannot be used as output (no drive capability); only suitable for analog/digital input.	🪛 Other
IO35	GPIO35	Cannot be used as output; only suitable for input.	🪛 Other
IO36	GPIO36 (SENSOR_VP)	Cannot be used as output; only suitable for input (e.g., analog read).	🪛 Other
IO37	GPIO37 (SENSOR_CAPP)	Cannot be used as output; only suitable for input.	🪛 Other
IO38	GPIO38 (SENSOR_CAPN)	Cannot be used as output; only suitable for input.	🪛 Other
IO39	GPIO39 (SENSOR_VN)	Cannot be used as output; only suitable for input.	🪛 Other