ESP32-S3 pinout

InteractiveOpen the ESP32-S3 in 3DTurn the real board over and click any of its 44 holes. Every pad is placed from this design’s own net list.Open in 3D →

Reading this board

Two 22-pin headers, 44 holes: 36 GPIO and eight power. The S3's GPIO matrix routes almost any peripheral to almost any pin, which is why people assume every pin is free. On the N16R8 module we ship, twelve are not; the table at the bottom of this page names each one and what has it.

Every row is read from this design's own net list, so the hole in the table is the hole on your desk. Open the board in 3D to turn it over and click one.

What the module takes

GPIO35, 36 and 37 belong to the octal PSRAM, and nothing about the board says so: the pads sit on the header looking like any other pin while the PSRAM is already running on them, before your setup() gets a turn. Drive one and you corrupt PSRAM traffic, which takes the chip down rather than failing quietly.

On a quad-PSRAM (R2) or no-PSRAM module they are ordinary GPIO. Quad PSRAM shares the flash bus inside the module and needs nothing of yours.

When it will not boot

GPIO0, 3, 45 and 46 are sampled once, as the chip leaves reset, to pick boot mode, JTAG source and flash voltage. Afterwards they are yours.

A board that flashes and runs over USB, then will not start on its own supply, is almost always one of those four. Something you wired — a pull-down on GPIO0, an LED on GPIO46 — holds a strapping pin at the wrong level while the rail comes up, and USB was rising slowly enough to hide it. Boot it bare, then add one wire at a time.

GPIO26 to 34 are in none of this because they are not on the board: the flash bus lives inside the module and never comes out.

Power

3V3 is the output of an AMS1117-3.3, and the module, the bridge and both LEDs already draw from it. Budget about 500 mA for your own parts, less once the radio is transmitting — the regulator is the ceiling, not what the USB port is willing to give.

5V is bus voltage, present only when USB is connected. RST is the regulator enable line, pulled up: tie it to ground through a button for a second reset button. All four GND holes are the same net, spread across both rows.

Buses

Defaults the Arduino core assumes, and the ones the examples on this site use:

Bus	Pins	Note
I²C	SDA GPIO8, SCL GPIO9	Remappable; 4.7 kΩ pull-ups needed if the module has none
SPI (HSPI)	MOSI GPIO11, MISO GPIO13, SCK GPIO12, SS GPIO10
SPI3 (VSPI)	MOSI GPIO35, SCK GPIO36, MISO GPIO37	The PSRAM pins — unusable on an R8
UART0	TX GPIO43, RX GPIO44	The USB serial console — leave it alone
UART1	TX GPIO17, RX GPIO18	`Serial1`, and yours

ADC

ADC1 is GPIO1 to GPIO10 and works whatever Wi-Fi is doing. ADC2 is GPIO11 to GPIO20 and stops the moment Wi-Fi starts, because the driver hands the block to the radio front end; a read returns an error from then on rather than a wrong number. An analog reading that dies at exactly the line where you call WiFi.begin() is this, and the fix is an ADC1 pin.

That leaves nine you can trust on a connected board: GPIO1, 2 and 4 through 10. GPIO3 is ADC1 as well, but it is one of the four above, so whatever you attach has to be quiet at reset.

Capacitive touch is T1 to T14, on GPIO1 to GPIO14.

Pins to leave alone

GPIO15 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO16 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO17 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO18 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO3 — Strapping pin. Selects the JTAG source. Floating at reset is the normal state.
GPIO46 — Strapping pin. Controls the ROM boot message. Must be low at reset.
GPIO11 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO12 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO13 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO14 — ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO43 — UART0 TX, wired to the USB-UART bridge behind the second USB-C port.
GPIO44 — UART0 RX, wired to the USB-UART bridge behind the second USB-C port.
GPIO37 — Octal PSRAM strobe on the N16R8. The pad is still on the header, which is what makes it a trap: drive it and you corrupt the module's own traffic, which usually takes the chip down. Free on a module that does not need the line.
GPIO36 — Octal PSRAM data line on the N16R8. The pad is still on the header, which is what makes it a trap: drive it and you corrupt the module's own traffic, which usually takes the chip down. Free on a module that does not need the line.
GPIO35 — Octal PSRAM data line on the N16R8. The pad is still on the header, which is what makes it a trap: drive it and you corrupt the module's own traffic, which usually takes the chip down. Free on a module that does not need the line.
GPIO0 — BOOT button, with a 10 kΩ pull-up. Held low at reset it drops the chip into the ROM bootloader.
GPIO45 — Strapping pin. Sets VDD_SPI to 3.3 V or 1.8 V. Must be low at reset on a 3.3 V module.
GPIO48 — WS2812B RGB LED, single-wire at 800 kHz. The silkscreen says RGB@IO48.
GPIO20 — Native USB-C, D+ . Wired straight to the USB-Serial-JTAG peripheral, no bridge chip in the path.
GPIO19 — Native USB-C, D− . Wired straight to the USB-Serial-JTAG peripheral, no bridge chip in the path.

Every pin

Pin	Name	Functions	Notes
3V3	3.3 V rail	power	L1. Output of the on-board regulator, not an input. Everything on the board runs from it. Budget what the regulator can spare, not what USB can deliver.
3V3	3.3 V rail	power	L2. Output of the on-board regulator, not an input. Everything on the board runs from it. Budget what the regulator can spare, not what USB can deliver.
RST	EN / reset	power	L3. The regulator enable line, pulled up. Tie it to ground through a button and you have a reset button.
GPIO4	GPIO4	gpio, adc1, touch	L4
GPIO5	GPIO5	gpio, adc1, touch	L5
GPIO6	GPIO6	gpio, adc1, touch	L6
GPIO7	GPIO7	gpio, adc1, touch	L7
GPIO15	GPIO15	gpio, adc2	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO16	GPIO16	gpio, adc2	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO17	GPIO17	gpio, adc2, uart	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO18	GPIO18	gpio, adc2, uart	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO8	GPIO8	gpio, adc1, touch, i2c	L12. Arduino default: Wire (I²C) SDA.
GPIO3	GPIO3	gpio, adc1, touch	Strapping pin. Selects the JTAG source. Floating at reset is the normal state.
GPIO46	GPIO46	gpio	Strapping pin. Controls the ROM boot message. Must be low at reset.
GPIO9	GPIO9	gpio, adc1, touch, i2c	L15. Arduino default: Wire (I²C) SCL.
GPIO10	GPIO10	gpio, adc1, touch, spi	L16. Arduino default: SPI (HSPI) SS.
GPIO11	GPIO11	gpio, adc2, touch, spi	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO12	GPIO12	gpio, adc2, touch, spi	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO13	GPIO13	gpio, adc2, touch, spi	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
GPIO14	GPIO14	gpio, adc2, touch	ADC2, so analogRead stops working the moment Wi-Fi starts. Unaffected as a digital pin.
5V	5 V rail	power	L21. The USB rail, upstream of the regulator. Feed the board here if you are not using USB, or take 5 V out if you are.
GND	Ground	power	L22. Ground. Several holes so a breadboard build has one nearby wherever it needs it.
GND	Ground	power	R1. Ground. Several holes so a breadboard build has one nearby wherever it needs it.
GPIO43	TX	gpio, uart	UART0 TX, wired to the USB-UART bridge behind the second USB-C port.
GPIO44	RX	gpio, uart	UART0 RX, wired to the USB-UART bridge behind the second USB-C port.
GPIO1	GPIO1	gpio, adc1, touch	R4
GPIO2	GPIO2	gpio, adc1, touch	R5
GPIO42	GPIO42	gpio, jtag	R6
GPIO41	GPIO41	gpio, jtag	R7
GPIO40	GPIO40	gpio, jtag	R8
GPIO39	GPIO39	gpio, jtag	R9
GPIO38	GPIO38	gpio	R10
GPIO37	GPIO37	gpio, spi	Octal PSRAM strobe on the N16R8. The pad is still on the header, which is what makes it a trap: drive it and you corrupt the module's own traffic, which usually takes the chip down. Free on a module that does not need the line.
GPIO36	GPIO36	gpio, spi	Octal PSRAM data line on the N16R8. The pad is still on the header, which is what makes it a trap: drive it and you corrupt the module's own traffic, which usually takes the chip down. Free on a module that does not need the line.
GPIO35	GPIO35	gpio, spi	Octal PSRAM data line on the N16R8. The pad is still on the header, which is what makes it a trap: drive it and you corrupt the module's own traffic, which usually takes the chip down. Free on a module that does not need the line.
GPIO0	GPIO0	gpio	BOOT button, with a 10 kΩ pull-up. Held low at reset it drops the chip into the ROM bootloader.
GPIO45	GPIO45	gpio	Strapping pin. Sets VDD_SPI to 3.3 V or 1.8 V. Must be low at reset on a 3.3 V module.
GPIO48	GPIO48	gpio	WS2812B RGB LED, single-wire at 800 kHz. The silkscreen says RGB@IO48.
GPIO47	GPIO47	gpio	R17
GPIO21	GPIO21	gpio	R18
GPIO20	GPIO20	gpio, adc2, usb	Native USB-C, D+ . Wired straight to the USB-Serial-JTAG peripheral, no bridge chip in the path.
GPIO19	GPIO19	gpio, adc2, usb	Native USB-C, D− . Wired straight to the USB-Serial-JTAG peripheral, no bridge chip in the path.
GND	Ground	power	R21. Ground. Several holes so a breadboard build has one nearby wherever it needs it.
GND	Ground	power	R22. Ground. Several holes so a breadboard build has one nearby wherever it needs it.

For this board

Slim Joystick — A thumb stick and six buttons on one long TinkerBlock board, on six pins. X and Y are two potentiometers, read on analog pins; KEY is the click under the stick, LOW at rest and HIGH when pushed; and all six buttons share BTNS, one analog pin, through a ladder of 10 kΩ resistors that gives each its own voltage. One button reads at a time.
ESP32-S3 PinPulse Shield pinout — Every hole on the Lonely Binary ESP32-S3 PinPulse Shield: 44 nets on a male pin and a female socket each, the LED on all 36 GPIOs, and what that LED costs the pin.
ESP32-S3 PinPulse Shield: an LED on All 36 GPIOs — The base for the Lonely Binary ESP32-S3: every GPIO on a male pin and a female socket with its own LED, six inverter chips so the lights cost your signals nothing, and a fifteen-way display port.
Dual Axis Joystick — A thumbstick on a square TinkerBlock board, on six pins: GND, VCC, NC, X, Y and SW. X and Y are two potentiometers from VCC to GND, read on analog pins; SW is the click under the stick, LOW at rest and HIGH when pressed, with its own pull-down. Every line reaches VCC, so VCC is your board's logic voltage. A PWR light and an SW light show power and each click.
INA219 and INA3221 Current Monitors: shunt, range and wiring — Two I²C current and voltage monitors: the TK119 with one INA219 on a 100 mΩ shunt, and the INA3221 with three channels on 50 mΩ. What the chip measures and what it works out, why the two resistors differ, the range and step each one gives, and the wiring for both.
INA219 Current Monitor — A 100 milliohm resistor in the positive wire and a chip that reads the millivolts across it. Current, voltage and power over I²C, up to 3.2 A on a rail of up to 26 V.
SD and microSD Card Readers for ESP32: SPI, 1-bit and 4-bit — Two 3.3 V card reader boards with the SD bus brought out in full. What the two NC pins really are, which of SPI, 1-bit and 4-bit to use, what each measured, and the wiring for all three.
SHT31 Temperature and Humidity Sensor — A Sensirion SHT31 on a TinkerBlock carrier: two numbers over two shared wires, calibrated at the factory, with the pull-ups already fitted and two jumpers on the back that set the address and take them away again.

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