Pinout Reference

Pin Header Layout

The ESP32-S3-DevKitC-1 exposes GPIO pins on two 22-pin headers (J1 and J3).

Left Header (J1) - Top to Bottom

Pin	Label	GPIO	Function	Notes
1	3V3	-	Power	3.3V output
2	3V3	-	Power	3.3V output
3	RST	CHIP_PU	Reset	Active low reset
4	4	GPIO4	ADC1_CH3	Touch, RTC
5	5	GPIO5	ADC1_CH4	Touch, RTC
6	6	GPIO6	ADC1_CH5	Touch, RTC
7	7	GPIO7	ADC1_CH6	Touch, RTC
8	15	GPIO15	ADC2_CH4	Touch, RTC
9	16	GPIO16	ADC2_CH5	Touch, RTC
10	17	GPIO17	ADC2_CH6	Touch, RTC
11	18	GPIO18	ADC2_CH7	Touch, RTC
12	8	GPIO8	ADC1_CH7	Touch, RTC
13	3	GPIO3	ADC1_CH2	Touch, RTC
14	46	GPIO46	-	Input only
15	9	GPIO9	ADC1_CH8	Touch, RTC
16	10	GPIO10	ADC1_CH9	Touch, RTC, FSPI
17	11	GPIO11	ADC2_CH0	Touch, RTC, FSPI
18	12	GPIO12	ADC2_CH1	Touch, RTC, FSPI
19	13	GPIO13	ADC2_CH2	Touch, RTC, FSPI
20	14	GPIO14	ADC2_CH3	Touch, RTC
21	5V	-	Power	5V input/output
22	G	GND	Ground

Right Header (J3) - Top to Bottom

Pin	Label	GPIO	Function	Notes
1	G	GND	Ground
2	TX	GPIO43	U0TXD	UART0 TX
3	RX	GPIO44	U0RXD	UART0 RX
4	1	GPIO1	ADC1_CH0	Touch, RTC
5	2	GPIO2	ADC1_CH1	Touch, RTC
6	42	GPIO42	-	JTAG MTMS
7	41	GPIO41	-	JTAG MTDI
8	40	GPIO40	-	JTAG MTDO
9	39	GPIO39	-	JTAG MTCK
10	38	GPIO38	-	RGB LED V1.1
11	37	GPIO37	-	PSRAM (N8R8/N16R8)
12	36	GPIO36	-	PSRAM (N8R8/N16R8)
13	35	GPIO35	-	PSRAM (N8R8/N16R8)
14	0	GPIO0	-	Boot strapping
15	45	GPIO45	-	VDD_SPI strapping
16	48	GPIO48	-	RGB LED V1.0
17	47	GPIO47	-	-
18	21	GPIO21	-	-
19	20	GPIO20	USB_D+	USB-OTG D+
20	19	GPIO19	USB_D-	USB-OTG D-
21	G	GND	Ground
22	G	GND	Ground

Pin Restrictions

PSRAM Pins Not Available

On N8R8 and N16R8 variants, GPIO35-37 are used internally for Octal PSRAM:

• GPIO35: SPI_DQS
• GPIO36: SPI_D4
• GPIO37: SPI_D5

These pins cannot be used for other purposes.

Strapping Pins

These pins have special functions during boot:

GPIO	Strapping Function	Default
GPIO0	Boot mode	Pull-up (normal boot)
GPIO45	VDD_SPI voltage	Pull-down (3.3V)
GPIO46	ROM messages	Pull-up (enable)

Tip

Avoid connecting external peripherals to strapping pins that might interfere with their default states during reset.

Input-Only Pins

GPIO	Notes
GPIO46	Cannot be used as output

USB Pins

GPIO19 and GPIO20 are used for native USB:

GPIO	USB Function
GPIO19	USB D-
GPIO20	USB D+

Note

If you use the USB-OTG functionality, these pins are not available for general GPIO use.

Peripheral Mapping

ADC Channels

ADC	GPIO Pins
ADC1	1, 2, 3, 4, 5, 6, 7, 8, 9, 10
ADC2	11, 12, 13, 14, 15, 16, 17, 18

Caution

ADC2 cannot be used while Wi-Fi is active. Use ADC1 channels for sensors that need to work alongside Wi-Fi.

Touch Sensors

Most GPIO pins (1-14) support capacitive touch sensing. These are useful for touch buttons without external components.

JTAG Debug

GPIO	JTAG Function
GPIO39	MTCK
GPIO40	MTDO
GPIO41	MTDI
GPIO42	MTMS

SPI Interfaces

FSPI (default SPI pins):

Function	GPIO
FSPI_CLK	GPIO12
FSPI_MOSI	GPIO11
FSPI_MISO	GPIO13
FSPI_CS	GPIO10

I2C (Any GPIO)

I2C can be mapped to any available GPIO. Common defaults:

Function	Suggested GPIO
SDA	GPIO8
SCL	GPIO9

UART

UART	TX	RX
UART0	GPIO43	GPIO44
UART1	Any	Any
UART2	Any	Any

Visual Pinout Diagram

Common Configurations

Minimal Sensor Project

GPIO4  → Temperature sensor
GPIO5  → Humidity sensor (I2C SDA)
GPIO6  → I2C SCL
GPIO38 → Status LED

Display + SD Card

GPIO10 → SPI CS (Display)
GPIO11 → SPI MOSI
GPIO12 → SPI CLK
GPIO13 → SPI MISO
GPIO14 → Display DC
GPIO15 → Display RST
GPIO16 → SD CS

See Also

• GPIO Table - Complete GPIO capabilities reference
• Memory Map - Memory configuration details
• Schematic - Full circuit schematic