Loading source-backed pinouts…
Microcontroller
Adafruit Metro ESP32-S3
An ESP32-S3 board in an Arduino-like Metro footprint with STEMMA QT and enough memory for rich CircuitPython projects.
Processor
ESP32-S3
Logic
3.3 V GPIO
Power
USB-C, barrel jack, LiPo connector
Format
Arduino shield-compatible Metro
Check before wiring
- ESP32-S3 IO is 3.3 V even though the board shape resembles classic Arduino.
- Analog pins map to ESP32 ADC resources with their usual limitations.
Interfaces
GPIOI2CSPIUARTADCPWMUSBWi-FiBluetooth
Source-backed connector
Interactive pin map
Pin map
Connector
Arduino Uno R3 shield headers
Signals grouped by function — schematic layout, not to physical scale
Dense header — open Full view for a roomier, fully-labelled diagram.
Simplified diagram, grouped by function — not to physical scale. Pin data is source-backed; verify against the linked documentation.
Hover, tap, or focus a pad to inspect a pin. Use arrow keys to move between pins.
- Arduino Uno / Metro shield footprint; ESP32-S3 GPIO from the official PrettyPins PDF.
- GPIO is 3.3 V only and is not 5 V tolerant (level-shift 5 V shields).
- Hardware SPI is on the 2x3 ICSP header (SCK=GPIO39, MOSI=GPIO42, MISO=GPIO21), NOT on D11/D12/D13 (those are plain GPIO11/12/13). NeoPixel on GPIO46; UART0 debug on GPIO43/44.
- I2C SDA=GPIO47 / SCL=GPIO48 are also brought out near AREF as on Uno R3.
All 32 pins (table)
| # | Signal | Role | Net | Also / notes |
|---|---|---|---|---|
| Digital (D0-D13) | ||||
| 1 | UART | UART | GPIO41 | |
| 2 | UART | UART | GPIO40 | |
| 3 | GPIO | GPIO2 | ||
| 4 | PWM | GPIO3 | ||
| 5 | GPIO | GPIO4 | ||
| 6 | PWM | GPIO5 | ||
| 7 | PWM | GPIO6 | ||
| 8 | GPIO | GPIO7 | ||
| 9 | GPIO | GPIO8 | ||
| 10 | PWM | GPIO9 | ||
| 11 | PWM | GPIO10 | ||
| 12 | GPIO | GPIO11 | ||
| 13 | GPIO | GPIO12 | ||
| 14 | GPIO | GPIO13 · onboard LED | ||
| Analog (A0-A5) | ||||
| 14 | ADC | GPIO14 | ||
| 15 | ADC | GPIO15 | ||
| 16 | ADC | GPIO16 | ||
| 17 | ADC | GPIO17 | ||
| 18 | ADC | GPIO18 | ||
| 19 | ADC | GPIO1 | ||
| I2C | ||||
| 20 | I2C | I2C | GPIO47 | |
| 21 | I2C | I2C | GPIO48 | |
| SPI (2x3 ICSP header) | ||||
| 29 | SPI | SPI | GPIO39 | |
| 30 | SPI | SPI | GPIO42 | |
| 31 | SPI | SPI | GPIO21 | |
| Power | ||||
| 22 | Power | VIN | 6-12 V barrel/header input | |
| 23 | Power | 5V | ||
| 24 | Power | 3V3 | ||
| 25 | Ground | GND | ||
| 26 | Power | VHIGH | level-shift rail for shields | |
| 27 | System | |||
| 28 | Alt | analog reference | ||
Why it matters
- Adafruit's pinout docs call out shield-facing logic pins.
- Bridges Arduino shield layout with modern ESP32-S3 features.
- Useful for classrooms that want Wi-Fi without leaving shield hardware behind.
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