BPI-Leaf-S3

A development board by Banana Pi featuring the ESP32-S3, designed for IoT and embedded applications.

USB-C Native USB
BPI-Leaf-S3 board
65.25 × 26 mm
ESP32-S3
MCU
240MHz
clock
8MB
flash
512KB
SRAM
23· 20 ADC
GPIO
BLE 5.0+ WiFi
radio
On this page

BPI-Leaf-S3 Pinout

23 pins · 2.54 mm pitch
BPI-Leaf-S3 pinout diagram
PinGPIOLabelsStatusCapabilitiesNotes
11A0T1PWMsafeadc · touch
22A1T2PWMsafeadc · touch
33A2T3PWMstrappingadc · touch
44A3T4PWMsafeadc · touch
55A4T5PWMsafeadc · touch
66A5T6PWMsafeadc · touch
77A6T7PWMsafeadc · touch
88A7T8PWMsafeadc · touch
99A8T9PWMstrappingadc · touch
1010SSA9T10PWMstrappingadc · touch · spi
1111MOSIA10T11PWMstrappingadc · touch · spi
1212SCKA11T12PWMstrappingadc · touch · spi
1313MISOA12T13PWMstrappingadc · touch · spi
1414A13T14PWMstrappingadc · touch
1515SDAA14PWMsafeadc · i2c
1616SCLA15PWMsafeadc · i2c
1717A16PWMsafeadc
1818A17PWMsafeadc
1919A18PWMuartadc
2020A19PWMuartadc
2143TXPWMuartuart
2244RXPWMuartuart
2348LED_BUILTINstrapping-
23 GPIOs broken out 11 free · 10 need care · 2 to avoid

Start with these

11 pins with no boot or system involvement
A0GPIO1A1GPIO2A3GPIO4A4GPIO5A5GPIO6A6GPIO7A7GPIO8SDAGPIO15SCLGPIO16A16GPIO17A17GPIO18

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

10 pins · 5 things to know
A2GPIO3 Bootstrapping pin (controls JTAG signal source) Strapping

Sampled at reset to select JTAG interface (USB Serial/JTAG controller vs. external pins). Improper use can disable external JTAG or alter debug interface.

A8GPIO9SSGPIO10MOSIGPIO11SCKGPIO12MISOGPIO13A13GPIO14 General-purpose SPI2 (FSPI) IO MUX pins Other

IO MUX pin of the general-purpose SPI2 (FSPI) bus, not of the in-package flash - that sits on GPIO26-32. The datasheet lists it as a priority-2 pin ("can be freely used without restrictions"), so it is only taken if your board wires flash, an SD card or a display to FSPI.

  • A8General-purpose SPI2 (FSPI) IO MUX pin - hold/data line (FSPIHD)
  • SSGeneral-purpose SPI2 (FSPI) IO MUX pin - chip select (FSPICS0)
  • MOSIGeneral-purpose SPI2 (FSPI) IO MUX pin - data in (FSPID)
  • SCKGeneral-purpose SPI2 (FSPI) IO MUX pin - clock (FSPICLK)
  • MISOGeneral-purpose SPI2 (FSPI) IO MUX pin - data out (FSPIQ)
  • A13General-purpose SPI2 (FSPI) IO MUX pin - write-protect/data line (FSPIWP)
TXGPIO43 UART0 transmit pin (U0TXD), default serial console TX UART

Used for bootloader output and UART console logs. If repurposed, you will lose the default serial output (and programming via UART0).

RXGPIO44 UART0 receive pin (U0RXD), default serial console RX UART

Used for bootloader input (download mode via serial). If repurposed, you cannot use the default UART0 download mode for programming the chip.

LED_BUILTINGPIO48 Octal SPI differential clock negative leg (SPICLK_N_DIFF), used only by the 1.8 V octal flash/PSRAM variants Other

Only the 1.8 V octal parts (ESP32-S3R8V, ESP32-S3R16V) run the differential memory clock here, and on those the pin works at 1.8 V instead of 3.3 V. On the common 3.3 V modules it is a normal GPIO - several devkits drive their RGB LED from GPIO48.

Only if you know the tricks

2 pins · 1 thing to know
A18GPIO19A19GPIO20 USB OTG differential data pair (D- and D+) USB

By default connected to the on-chip USB Serial/JTAG controller. Using it as general GPIO without reconfiguring IO MUX will interfere with USB functionality.

  • A18USB OTG negative differential data line (USB_D-)
  • A19USB OTG positive differential data line (USB_D+)
These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.

All 23 pins on the BPI-Leaf-S3 are usable GPIO, spaced at the standard 2.54 mm pitch.

Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO15 and SCL on GPIO16; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.

Beyond plain digital I/O you get 20 ADC-capable pins for sensors and battery monitoring and 14 capacitive-touch inputs.

10 of the exposed pins carry boot-time or system duties on the ESP32-S3 (A2, A8, SS and 7 more) - check the guidance above before wiring anything to them. A0, A1, A3, A4 and 7 more are free of any such role - the safest first picks.

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Native USB - shows up as a port right away, no driver needed. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
GPIO1 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.
Set these in Tools · leave everything else at default
Arduino IDE 2.x - Tools Copy
Board: "ESP32S3 Dev Module"▸
USB CDC On Boot: "Enabled"▸
Flash Size: "8MB (64Mb)"▸
Flash Mode: "DIO"▸
PSRAM: "QSPI PSRAM"▸
Partition Scheme: "8M with spiffs (3MB APP/1.5MB SPIFFS)" (default)▸
Upload Speed: "921600"▸
▸ every other Tools option - leave at default
Board: ESP32S3 Dev Module
USB CDC On Boot: Enabled
Flash Size: 8MB (64Mb)
Flash Mode: DIO
PSRAM: QSPI PSRAM
Partition Scheme: 8M with spiffs (3MB APP/1.5MB SPIFFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32S3 Dev Module
blink.ino Copy
// toggle GPIO1 - wire an LED and resistor to it
void setup() {
  pinMode(1, OUTPUT);
}
void loop() {
  digitalWrite(1, HIGH); delay(500);
  digitalWrite(1, LOW);  delay(500);
}
board to selectesp32-s3-devkitc-1⧉ copy
platformio.ini Copy
[env:bpi_leaf_s3]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_qspi
build_flags = -DBOARD_HAS_PSRAM
Find it: PlatformIO Home ▸ Boards, search esp32-s3-devkitc-1 - or type it after board =.
board to selectesp32-s3-devkitc-1⧉ copy
device.yaml Copy
esp32:
  board: esp32-s3-devkitc-1
  variant: esp32s3
  framework:
    type: esp-idf
psram:
  mode: quad
  speed: 80MHz

# blink - GPIO1
output:
  - platform: gpio
    pin: 1
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
Find it: search ESPHome's board list for esp32-s3-devkitc-1 (same ids as PlatformIO).
esptool doesn't pick board settings - a prebuilt .bin already has them baked in. This is just the raw flash command.
terminal Copy
esptool.py --chip esp32s3 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x0 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32-S3 · 65.25 × 26 mm · vs other ESP32 chips →
Compute
MCU
ESP32-S3
Clock
240 MHz
SRAM · Flash
512 KB · 8MB · 2MB (QSPI) PSRAM
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
5.0 LE
Antenna
PCB
I/O
GPIO · ADC
23 · 20
UART · I²C · SPI
3 · 2 · 2
PWM
8 channels
Power
USB
USB-C
Serial
Native (CDC)
Boot address
0x0
Electrical
Input
5V USB · 3.75-6V VIN · 3.7V LiPo
Consumption
10µA sleep
Regulator
SY8089AAAC
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · QIO
Sketch · Data
1.25 MB · 320 KB

Dimensions

26 mm65.25 mm
65.25 × 26 mm · pin pitch 2.54 mm
The BPI-Leaf-S3 uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with QIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

Inside sits the ESP32-S3 - a dual-core Xtensa with vector extensions suited to AI workloads.

At $7.50 it's cheaper than most ESP32-S3 boards, which usually run around $29.

Around the module: 2MB (QSPI) PSRAM, a Qwiic/STEMMA QT connector, an addressable RGB LED (GPIO48), battery charging (MCP73831) and Reset/Boot buttons.

It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S3 boards.

Where to buy

prices are typical street prices
BPI-Leaf-S3
BPI-Leaf-S3
$7.50per unit, typical

Resources

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