Adafruit Feather ESP32-S3 Reverse TFT
A variant of the Feather ESP32-S3 with a reverse-mounted TFT display, allowing for different mounting options in projects.
Adafruit Feather ESP32-S3 Reverse TFT Pinout
27 pins · 2.54 mm pitch
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 3 | SDAPWM | strapping | i2c | |
| 2 | 4 | SCLPWM | safe | i2c | |
| 3 | 5 | T5PWM | safe | touch | |
| 4 | 6 | T6PWM | safe | touch | |
| 5 | 7 | TFT_I2C_POWERPWM | safe | - | |
| 6 | 8 | A5T8PWM | safe | adc · touch | |
| 7 | 9 | T9PWM | strapping | touch | |
| 8 | 10 | T10PWM | strapping | touch | |
| 9 | 11 | T11PWM | strapping | touch | |
| 10 | 12 | T12PWM | strapping | touch | |
| 11 | 13 | LED_BUILTINT13PWM | strapping | touch | |
| 12 | 14 | A4T14PWM | strapping | adc · touch | |
| 13 | 15 | A3PWM | safe | adc | |
| 14 | 16 | A2PWM | safe | adc | |
| 15 | 17 | A1DAC1PWM | safe | adc · dac | |
| 16 | 18 | A0DAC2PWM | safe | adc · dac | |
| 17 | 21 | NEOPIXEL_POWERPWM | safe | - | |
| 18 | 33 | PIN_NEOPIXELPWM | safe | - | |
| 19 | 35 | MOSIPWM | safe | spi | |
| 20 | 36 | SCKPWM | safe | spi | |
| 21 | 37 | MISOPWM | safe | spi | |
| 22 | 38 | RXPWM | uart | uart | |
| 23 | 39 | TXPWM | strapping | uart | |
| 24 | 40 | TFT_DCPWM | strapping | - | |
| 25 | 41 | TFT_RSTPWM | strapping | - | |
| 26 | 42 | TFT_CSSSPWM | strapping | spi | |
| 27 | 45 | TFT_BACKLITEPWM | strapping | - |
Start with these
15 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
12 pins · 7 things to knowSDAGPIO3 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.
T9GPIO9T10GPIO10T11GPIO11T12GPIO12LED_BUILTINGPIO13A4GPIO14 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.
- T9General-purpose SPI2 (FSPI) IO MUX pin - hold/data line (FSPIHD)
- T10General-purpose SPI2 (FSPI) IO MUX pin - chip select (FSPICS0)
- T11General-purpose SPI2 (FSPI) IO MUX pin - data in (FSPID)
- T12General-purpose SPI2 (FSPI) IO MUX pin - clock (FSPICLK)
- LED_BUILTINGeneral-purpose SPI2 (FSPI) IO MUX pin - data out (FSPIQ)
- A4General-purpose SPI2 (FSPI) IO MUX pin - write-protect/data line (FSPIWP)
TXGPIO39 JTAG test clock (MTCK); IO MUX alternates CLK_OUT3 and SUBSPICS1 (chip select on the alternative SUBSPI memory bus, unused on standard modules) JTAG
Default JTAG TCK - keep it free if you debug over JTAG. It is not a flash or PSRAM line on standard modules: those sit on GPIO26-37.
TFT_DCGPIO40 JTAG test data out pin (MTDO) JTAG
Default JTAG TDO output for debugging. Using it as GPIO will interfere with JTAG debugging functionality.
TFT_RSTGPIO41 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.
TFT_CSGPIO42 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).
TFT_BACKLITEGPIO45 Bootstrapping pin (selects VDD_SPI flash voltage) Strapping
Determines flash/PSRAM power voltage (3.3 V vs 1.8 V) at boot. Must match hardware configuration; using as GPIO can upset flash supply setting.
All 27 pins on the Adafruit Feather ESP32-S3 Reverse TFT are usable GPIO, spaced at the standard 2.54 mm pitch.
Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO3 and SCL on GPIO4; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO39 and GPIO38 cover serial logging and flashing.
Beyond plain digital I/O you get 6 ADC-capable pins for sensors and battery monitoring, 9 capacitive-touch inputs and 2 true DAC outputs.
12 of the exposed pins carry boot-time or system duties on the ESP32-S3 (SDA, T9, T10 and 9 more) - check the guidance above before wiring anything to them. SCL, T5, T6, TFT_I2C_POWER and 11 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: 4MB (32Mb) Flash Mode: DIO PSRAM: QSPI PSRAM Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS) Upload Speed: 921600
// toggle GPIO4 - wire an LED and resistor to it
void setup() {
pinMode(4, OUTPUT);
}
void loop() {
digitalWrite(4, HIGH); delay(500);
digitalWrite(4, LOW); delay(500);
}[env:adafruit_feather_esp32s3_reversetft]
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_PSRAMesp32-s3-devkitc-1 - or type it after board =.esp32:
board: esp32-s3-devkitc-1
variant: esp32s3
framework:
type: esp-idf
psram:
mode: quad
speed: 80MHz
# blink - GPIO4
output:
- platform: gpio
pin: 4
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 · vs other ESP32 chips →Dimensions
About this board
Inside sits the ESP32-S3 - a dual-core Xtensa with vector extensions suited to AI workloads.
The $24.95 price tag is typical for an ESP32-S3 board.
Around the module: 2MB (QSPI) PSRAM, a TFT 1.14" 240x135 display, a STEMMA QT connector, an addressable RGB LED (GPIO33), a battery fuel gauge (MAX17048), battery charging (MCP73831) via JST-PH 2.0, status LEDs (On, Charge, User (D13)) and Reset/D0/D1/D2 buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S3 boards.
- Early units shipped with an LC709203F fuel gauge instead of the MAX17048
Where to buy
prices are typical street pricesResources
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