Seeed Studio XIAO ESP32S3 Plus Pinout
The XIAO ESP32S3 Plus is the expanded member of the Seeed Studio XIAO ESP32S3 family. It keeps the thumb-sized 21 × 17.8 mm XIAO outline and the same ESP32-S3R8 chip as the XIAO ESP32S3, but doubles the flash memory to 16 MB and brings many more of the chip's GPIO out to the edge of the board.
The ESP32-S3R8 combines a dual-core 32-bit Xtensa LX7 processor running at up to 240 MHz with 8 MB of PSRAM inside the chip package. Programs are stored in a separate 16 MB (128 Mbit) PY25Q128HA SPI flash chip. The chip provides 2.4 GHz Wi-Fi and Bluetooth Low Energy 5.0 with Bluetooth Mesh, and the board brings the radio out to a U.FL connector for an external antenna.
Compared with the XIAO ESP32S3, the Plus version adds:
- 16 MB of flash memory instead of 8 MB
- Nine extra castellated pads, D11 to D19, alongside the 14 standard XIAO pads, for 20 digital pins in total
- A second SPI bus on D17 to D19 and a second UART defined in the Arduino core
- A 30-pin board-to-board (B2B) connector on the back that works with the Wio-SX1262 extension board, but not with the camera sensor board of the XIAO ESP32S3 Sense
Key features of the XIAO ESP32S3 Plus include:
- ESP32-S3R8 with a dual-core Xtensa LX7 processor at up to 240 MHz
- 8 MB PSRAM and 16 MB SPI flash
- 2.4 GHz Wi-Fi (802.11 b/g/n) and Bluetooth LE 5.0, with a U.FL antenna connector
- 20 digital I/O pins at 3.3 V, 13 of them connected to ADC channels
- 2 × UART, 1 × I2C, 2 × I2S and 2 × SPI
- USB Type-C for power, programming and battery charging
- Lithium battery charger with a charge LED
- Reset and Boot buttons and a user LED on GPIO21
- JTAG, EN and USB test pads on the back
XIAO ESP32S3 Plus Technical Specification
| Platform | |
|---|---|
| Manufacturer | Seeed Studio |
| Processor | ESP32-S3 |
| Processor Family | Xtensa LX7 |
| Clock Speed | 240 MHz |
| Flash Memory | 16 MB |
| SRAM | 512 KB |
| I/O | |
|---|---|
| Digital I/O | 20 |
| Analog Input | 13 |
| PWM | 20 |
| ADC Resolution | 4096 |
| Interrupts | 20 |
| Power | |
|---|---|
| Input Voltage | 5 V |
| I/O Voltage | 3.3 V |
| I/O Current |
| Communication Protocols | |
|---|---|
| I2C | 1x |
| I2S | 2x |
| SPI | 2x |
| UART | 2x |
| Connectivity | |
|---|---|
| USB Type C | 1x Used to power the board, communication as well as charging the battery |
| WiFi | 802.11b 802.11g 802.11n U.FL connector for an external antenna |
| Bluetooth | 5.0 |
| Sensors | |
|---|---|
| Touch | Provided by ESP32-S3 |
| Peripherals | |
|---|---|
| RTC | 2x 64 bit |
| Timer | 4x 52 bit |
| Watchdog Timer | 3 |
| Cryptography | AES/DS/HMAC/RSA/SHA Accelerator |
| Debug/Trace | JTAG MTCK, MTDO, MTDI and MTMS pads on the back, shared with D12 to D15 |
| Dimensions | |
|---|---|
| Width | 21 mm |
| Length | 17.8 mm |
XIAO ESP32S3 Plus Pin Headers and Components
The XIAO ESP32S3 Plus keeps the classic XIAO form factor, and adds extra pads along the edges and a set of test pads on the back.
Dimensions
The board measures 21 × 17.8 mm, the same as the XIAO ESP32S3. Seeed rates it for operation from -20 °C to 65 °C.
Castellated pads
The 23 castellated pads in the XIAO ESP32S3 Plus pinout run along the two long edges, so the board can be soldered directly onto a carrier PCB or fitted with pin headers. The 14 standard XIAO pads (D0 to D10, 5V, GND and 3V3) keep their usual positions. The nine extra pads sit between them: D11 to D16 alternate with D0 to D6 on one edge, and D17 to D19 alternate with D10, D9, D8 and D7 on the other.
USB Type-C connector
The USB Type-C connector is wired to the ESP32-S3's native USB data lines. It powers the board, charges a connected battery and is used for programming and serial communication.
B2B connector
A 30-pin board-to-board connector on the back carries power, the user LED signal and a group of GPIO. Besides signals that are also on the edge pads, it carries GPIO14 to GPIO18, GPIO47 and GPIO48, which are not available on any edge pad. According to Seeed, it is compatible with the Wio-SX1262 extension board but not with the plug-in camera sensor board.
Antenna connector
Wi-Fi and Bluetooth use an external antenna plugged into the U.FL connector. Seeed recommends fitting the antenna supplied with the board for better signal, and quotes a range of more than 100 m with it.
Reset and Boot buttons
The Reset button pulls the chip's EN line low to restart the ESP32-S3. The Boot button is connected to GPIO0, a strapping pin: holding it while the board powers up starts the ESP32-S3 in bootloader mode.
LEDs
The user LED is connected to GPIO21, which the Arduino core defines as LED_BUILTIN. Its cathode is wired to GPIO21, so it lights when the pin is driven low. A red charge LED is driven by the battery charger.
Test pads on the back
Eight small pads on the back expose the JTAG signals MTCK, MTDO, MTDI and MTMS, the EN line, GND, and the USB D+ and D- lines. Two more pads, BAT and GND, are for connecting a battery.
Powering XIAO ESP32S3 Plus
The XIAO ESP32S3 Plus runs from 5 V over USB Type-C or from a 3.7 V lithium battery. An SGM6029 switching regulator produces the 3.3 V rail for the ESP32-S3 and the 3V3 pin, and an SGM40567-4.2 charger charges the battery from USB.
USB Type-C
USB power reaches the regulator through a Schottky diode and also feeds the battery charger. A P-channel MOSFET between the battery and the regulator input lets the board run from the battery when USB is not connected.
5V pin
The 5V pin in the XIAO ESP32S3 Plus pinout is connected to the USB VBUS line, so it outputs 5 V when the board is plugged into USB. It can also be used as a power input, but Seeed advises placing a diode (Schottky, signal or power) between the external supply and this pin, with the anode on the supply side and the cathode on the 5V pin. When the board runs from its battery, there is no voltage on the 5V pin.
3V3 pin
3V3 is the output of the on-board regulator and can power external 3.3 V circuits. Seeed's wiki says up to 700 mA can be drawn from the 3V3 pin of the XIAO ESP32S3 series.
GND pin
GND is the common ground for power, data and signals.
Battery pads
A 3.7 V rechargeable lithium battery connects to the BAT and GND pads on the back. The charger's current is set to about 110 mA in the schematic. According to Seeed, the red charge LED comes on for 30 seconds when USB is connected without a battery, flashes while the battery charges, and turns off once it is full.
The Arduino core names GPIO10 ADC_BAT (BAT_VOLT_PIN), and Seeed's pin map describes it as reading the battery voltage. GPIO10 is also the D16 pad. However, the V1.1 KiCad design published by Seeed shows no connection between the battery and GPIO10 on the board itself, so check your board revision before relying on it.
Power consumption
Seeed lists the following typical figures for the Plus, measured with a 3.8 V supply for the low-power modes:
- Circuit operating current: 28 mA at 5 V over USB, 35 mA at 3.8 V from the battery
- Wi-Fi active: 81 mA
- Bluetooth LE active: 101 mA
- Modem-sleep: 31.6 mA
- Light-sleep: 2.45 mA
- Deep sleep: 33.51 μA
XIAO ESP32S3 Plus Pinout and Peripherals
All peripherals come from the ESP32-S3. Its GPIO matrix can route most digital functions to almost any pin, so the functions below are the defaults used by the Arduino core and Seeed's pin map.
Digital GPIO
The XIAO ESP32S3 Plus pinout has 20 digital I/O pins, D0 to D19, all using 3.3 V logic. D0 to D10 are the standard XIAO pins, and D11 to D19 are the extra pads of the Plus version. Every pin can be used for PWM output through the ESP32-S3's LED PWM controller and as an interrupt source.
Analog to Digital Converter (ADC)
The ESP32-S3 has two 12-bit ADCs. In the XIAO ESP32S3 Plus pinout, 13 pads can read analog voltages:
- ADC1: D0 to D5 (A0 to A5), D8 to D10 (A8 to A10) and D16.
- ADC2: D17, D18 and D19. ADC2 is shared with Wi-Fi, so use the ADC1 pads for analog readings in Wi-Fi projects.
- No ADC: D11 to D15 (GPIO38 to GPIO42), even though some rows of Seeed's pin map mark them as analog.
Capacitive touch
D0 to D5 and D8 to D10 are touch channels TOUCH1 to TOUCH9 (T1 to T9 in the Arduino core). D16, D17, D18 and D19 are touch channels TOUCH10, TOUCH13, TOUCH12 and TOUCH11.
UART
The default serial pins are D6 (TX, GPIO43) and D7 (RX, GPIO44). The Arduino core also defines TX1 on D15 (GPIO42) and RX1 on D14 (GPIO41) for a second UART. Those two pads are shared with the PDM and JTAG functions described below.
I2C
The default I2C bus uses D4 (SDA, GPIO5) and D5 (SCL, GPIO6).
SPI
The default SPI bus uses D8 (SCK, GPIO7), D9 (MISO, GPIO8) and D10 (MOSI, GPIO9). The D17, D18 and D19 pins in the XIAO ESP32S3 Plus pinout carry a second SPI bus, which the Arduino core defines as SCK1 (GPIO13), MISO1 (GPIO12) and MOSI1 (GPIO11).
I2S and PDM
The Arduino core defines I2S signals on D11 (I2S_SD, GPIO38), D12 (I2S_SCK, GPIO39) and D13 (I2S_WS, GPIO40). In the schematic, D14 (GPIO41) and D15 (GPIO42) are labelled PDM_DATA and PDM_CLK, the two signals a PDM microphone needs.
JTAG
D12 to D15 in the XIAO ESP32S3 Plus pinout are also the ESP32-S3 JTAG pins: D12 is MTCK (GPIO39), D13 is MTDO (GPIO40), D14 is MTDI (GPIO41) and D15 is MTMS (GPIO42). The MTCK, MTDO, MTDI and MTMS test pads on the back are wired to the same signals, so a JTAG probe on those pads and a circuit on D12 to D15 share the same pins.
Wi-Fi and Bluetooth
The ESP32-S3 provides a complete 2.4 GHz Wi-Fi subsystem (802.11 b/g/n) and Bluetooth Low Energy 5.0 with Bluetooth Mesh. The radio uses the external antenna on the U.FL connector.
Timers and security
The ESP32-S3 provides four general-purpose timers, three watchdog timers, and hardware accelerators for AES, RSA, SHA, HMAC and digital signatures (DS).
Programming XIAO ESP32S3 Plus
- Arduino IDE: The Espressif Arduino-ESP32 core includes a dedicated XIAO_ESP32S3_Plus variant with the D0 to D19 pin names, the second SPI bus and the user LED.
- Arduino CLI: The same Arduino-ESP32 core and board definition can be used from the command line.
- MicroPython: The board can be programmed in Python with MicroPython, which Seeed documents for the XIAO ESP32S3 series.
- CircuitPython: CircuitPython also supports the XIAO ESP32S3 Plus, as another way to program it in Python.
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