Cytron Maker Feather AIoT S3
A Feather-format ESP32-S3 board by Cytron, designed for AIoT applications with various peripheral support.
Cytron Maker Feather AIoT S3 Pinout
21 pins · 2.54 mm pitch| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | BOOT | strapping | - | |
| 2 | 2 | LED_BUILTINPWM | safe | - | |
| 3 | 3 | BUTTONPWM | strapping | - | |
| 4 | 4 | A4T4PWM | safe | adc · touch | |
| 5 | 5 | A3T5PWM | safe | adc · touch | |
| 6 | 6 | A2T6PWM | safe | adc · touch | |
| 7 | 7 | SSA5T7PWM | safe | adc · touch · spi | |
| 8 | 8 | MOSIA7T8PWM | safe | adc · touch · spi | |
| 9 | 9 | A1T9PWM | strapping | adc · touch | |
| 10 | 10 | A0T10PWM | strapping | adc · touch | |
| 11 | 11 | VP_ENPWM | strapping | - | |
| 12 | 12 | BUZZERPWM | strapping | - | |
| 13 | 13 | VINVBATTVOLTAGE_MONITORA12PWM | power | adc | |
| 14 | 14 | A11T14PWM | strapping | adc · touch | |
| 15 | 15 | TXA10PWM | uart | adc · uart | |
| 16 | 16 | RXA9PWM | uart | adc · uart | |
| 17 | 17 | SCKA6PWM | safe | adc · spi | |
| 18 | 18 | MISOA8PWM | safe | adc · spi | |
| 19 | 41 | SCLPWM | strapping | i2c | |
| 20 | 42 | SDAPWM | strapping | i2c | |
| 21 | 46 | RGB_BUILTIN | strapping | - |
Start with these
10 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
10 pins · 6 things to knowBOOTGPIO0 Bootstrapping pin (Chip boot mode selection) Strapping
Must be pulled high (default) or low (to enter UART download mode) at reset. Using it for other functions can interfere with boot mode configuration.
BUTTONGPIO3 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.
A1GPIO9A0GPIO10VP_ENGPIO11BUZZERGPIO12A11GPIO14 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.
- A1General-purpose SPI2 (FSPI) IO MUX pin - hold/data line (FSPIHD)
- A0General-purpose SPI2 (FSPI) IO MUX pin - chip select (FSPICS0)
- VP_ENGeneral-purpose SPI2 (FSPI) IO MUX pin - data in (FSPID)
- BUZZERGeneral-purpose SPI2 (FSPI) IO MUX pin - clock (FSPICLK)
- A11General-purpose SPI2 (FSPI) IO MUX pin - write-protect/data line (FSPIWP)
SCLGPIO41 JTAG test data in pin (MTDI) JTAG
Default JTAG TDI input for debugging. Should be reserved for JTAG or left unused if JTAG is to remain available.
SDAGPIO42 JTAG test mode select pin (MTMS) JTAG
Default JTAG TMS signal for debugging. Using this pin for other purposes will disable the JTAG interface (unless JTAG is rerouted to USB).
RGB_BUILTINGPIO46 Bootstrapping pin (used with GPIO0 for boot mode; controls ROM log output) Strapping
Must be at a defined level during reset (with GPIO0) to select normal or download boot and UART/USB print mode. This pin is input-only (no output drive), so it should be left for its intended strapping function.
Across 21 pins (2.54 mm pitch), the Cytron Maker Feather AIoT S3 exposes 20 GPIO plus VIN for power.
Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO42 and SCL on GPIO41; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO15 and GPIO16 cover serial logging and flashing.
Beyond plain digital I/O you get 12 ADC-capable pins for sensors and battery monitoring and 8 capacitive-touch inputs.
10 of the exposed pins carry boot-time or system duties on the ESP32-S3 (BOOT, BUTTON, A1 and 7 more) - check the guidance above before wiring anything to them. LED_BUILTIN, A4, A3, A2 and 6 more are free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32S3 Dev Module USB CDC On Boot: Enabled Flash Size: 8MB (64Mb) Flash Mode: DIO PSRAM: OPI PSRAM Partition Scheme: 8M with spiffs (3MB APP/1.5MB SPIFFS) Upload Speed: 921600
// toggle GPIO2 - wire an LED and resistor to it
void setup() {
pinMode(2, OUTPUT);
}
void loop() {
digitalWrite(2, HIGH); delay(500);
digitalWrite(2, LOW); delay(500);
}[env:cytron_maker_feather_aiot_s3]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_opi
build_flags = -DBOARD_HAS_PSRAMesp32-s3-devkitc-1 - or type it after board =.esp32:
board: esp32-s3-devkitc-1
variant: esp32s3
framework:
type: esp-idf
psram:
mode: octal
speed: 80MHz
# blink - GPIO2
output:
- platform: gpio
pin: 2
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32-s3-devkitc-1 (same ids as PlatformIO).esptool.py --chip esp32s3 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x0 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32-S3 · 58.4 × 22.9 mm · vs other ESP32 chips →Dimensions
About this board
Inside sits the ESP32-S3 - a dual-core Xtensa with vector extensions suited to AI workloads.
At $19.95 it's cheaper than most ESP32-S3 boards, which usually run around $29.
Around the module: 8MB (OPI) PSRAM, a STEMMA QT connector, an addressable RGB LED (GPIO46), a buzzer, battery charging via JST-PH 2.0, status LEDs (Power, VPeripheral, Charge, User) and Reset/Boot/User buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S3 boards.
- 11 GPIO status indicator LEDs
- Switchable VPeripheral power rail for 2 of the 3 Maker Ports
- Onboard battery voltage monitor on GPIO13
- Piezo buzzer with mute switch
Where to buy
prices are typical street pricesResources
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