GPIO Table

GPIO Overview

The ESP32-S3 has 45 GPIO pins (GPIO0-21, GPIO26-48). Not all are available on the DevKitC-1 due to internal flash/PSRAM usage.

Complete GPIO Reference

GPIO	Header	ADC	Touch	RTC	Default Function	Notes
0	J3-14	-	-	Yes	Boot strapping	Hold low for download mode
1	J3-4	ADC1_0	T1	Yes	General I/O
2	J3-5	ADC1_1	T2	Yes	General I/O
3	J1-13	ADC1_2	T3	Yes	General I/O
4	J1-4	ADC1_3	T4	Yes	General I/O
5	J1-5	ADC1_4	T5	Yes	General I/O
6	J1-6	ADC1_5	T6	Yes	General I/O
7	J1-7	ADC1_6	T7	Yes	General I/O
8	J1-12	ADC1_7	T8	Yes	General I/O
9	J1-15	ADC1_8	T9	Yes	General I/O
10	J1-16	ADC1_9	T10	Yes	FSPI_CS	SPI chip select
11	J1-17	ADC2_0	T11	Yes	FSPI_MOSI	SPI data out
12	J1-18	ADC2_1	T12	Yes	FSPI_CLK	SPI clock
13	J1-19	ADC2_2	T13	Yes	FSPI_MISO	SPI data in
14	J1-20	ADC2_3	T14	Yes	General I/O
15	J1-8	ADC2_4	-	Yes	General I/O
16	J1-9	ADC2_5	-	Yes	General I/O
17	J1-10	ADC2_6	-	Yes	General I/O
18	J1-11	ADC2_7	-	Yes	General I/O
19	J3-20	-	-	-	USB D-	USB
20	J3-19	-	-	-	USB D+	USB
21	J3-18	-	-	-	General I/O
35	J3-13	-	-	-	PSRAM	N8R8/N16R8 Only
36	J3-12	-	-	-	PSRAM	N8R8/N16R8 Only
37	J3-11	-	-	-	PSRAM	N8R8/N16R8 Only
38	J3-10	-	-	-	RGB LED	V1.1
39	J3-9	-	-	-	JTAG MTCK	Debug
40	J3-8	-	-	-	JTAG MTDO	Debug
41	J3-7	-	-	-	JTAG MTDI	Debug
42	J3-6	-	-	-	JTAG MTMS	Debug
43	J3-2	-	-	-	U0TXD	UART TX
44	J3-3	-	-	-	U0RXD	UART RX
45	J3-15	-	-	-	VDD_SPI strap	Strapping pin
46	J1-14	-	-	-	Input only	Input Only
47	J3-17	-	-	-	General I/O
48	J3-16	-	-	-	RGB LED	V1.0

Pin Restrictions

Strapping Pins

Caution

These pins determine boot behavior. Avoid connecting loads that change their state during reset.

GPIO	Function	Default	Effect
GPIO0	Boot mode	HIGH (pulled up)	LOW = download mode
GPIO45	VDD_SPI	LOW (pulled down)	HIGH = 1.8V flash
GPIO46	ROM log	HIGH (pulled up)	LOW = disable logs

USB Pins

GPIO19 and GPIO20 are dedicated USB pins when USB functionality is enabled:

GPIO	USB Function	Notes
GPIO19	USB_D-	Cannot use as GPIO when USB active
GPIO20	USB_D+	Cannot use as GPIO when USB active

PSRAM Pins (N8R8/N16R8)

Do Not Use

On N8R8 and N16R8 variants, these pins are used internally for Octal PSRAM.

GPIO	PSRAM Function
GPIO35	SPI_DQS
GPIO36	SPI_D4
GPIO37	SPI_D5

Input-Only Pins

GPIO	Notes
GPIO46	Cannot output, can only read input

ADC Channels

ADC1 (10 channels)

Works in all conditions:

Channel	GPIO
ADC1_CH0	GPIO1
ADC1_CH1	GPIO2
ADC1_CH2	GPIO3
ADC1_CH3	GPIO4
ADC1_CH4	GPIO5
ADC1_CH5	GPIO6
ADC1_CH6	GPIO7
ADC1_CH7	GPIO8
ADC1_CH8	GPIO9
ADC1_CH9	GPIO10

ADC2 (10 channels)

Caution

ADC2 channels cannot be used when Wi-Fi is active.

Channel	GPIO
ADC2_CH0	GPIO11
ADC2_CH1	GPIO12
ADC2_CH2	GPIO13
ADC2_CH3	GPIO14
ADC2_CH4	GPIO15
ADC2_CH5	GPIO16
ADC2_CH6	GPIO17
ADC2_CH7	GPIO18
ADC2_CH8	GPIO19 (USB)
ADC2_CH9	GPIO20 (USB)

Touch Sensors

14 capacitive touch pins (T1-T14):

Touch	GPIO
T1	GPIO1
T2	GPIO2
T3	GPIO3
T4	GPIO4
T5	GPIO5
T6	GPIO6
T7	GPIO7
T8	GPIO8
T9	GPIO9
T10	GPIO10
T11	GPIO11
T12	GPIO12
T13	GPIO13
T14	GPIO14

Peripheral Mapping

Default SPI (FSPI)

Function	GPIO
FSPI_CLK	GPIO12
FSPI_MOSI	GPIO11
FSPI_MISO	GPIO13
FSPI_CS	GPIO10

UART

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

I2C

I2C can be assigned to any GPIO. Common defaults:

Function	Suggested GPIO
SDA	GPIO8
SCL	GPIO9

JTAG Debug

Function	GPIO
MTCK	GPIO39
MTDO	GPIO40
MTDI	GPIO41
MTMS	GPIO42

Recommended Pin Assignments

Sensor Project

GPIO4  → I2C SDA
GPIO5  → I2C SCL
GPIO6  → Button input
GPIO38 → Status LED

Display + SD Card

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

Motor Control

GPIO4  → PWM Motor A
GPIO5  → PWM Motor B
GPIO6  → Direction A
GPIO7  → Direction B
GPIO8  → Encoder A
GPIO9  → Encoder B

Related Pages

• Pinout Reference
• Memory Configuration
• Specifications