Adafruit QT Py ESP32
Ultra-compact ESP32 board with STEMMA QT - perfect for plug-and-play sensor projects and tight-space builds.
Adafruit QT Py ESP32 Pinout
17 pins · 2.54 mm pitch
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | BUTTON | strapping | - | |
| 2 | 1 | WIRE1_PIN_DEFINEDPWM | uart | - | |
| 3 | 4 | SDAA4T0PWM | safe | adc · touch · i2c | |
| 4 | 5 | PIN_NEOPIXELPWM | strapping | - | |
| 5 | 7 | RXRX1A7PWM | strapping | adc · uart | |
| 6 | 8 | NEOPIXEL_POWERPWM | strapping | - | |
| 7 | 12 | MISOA9T5PWM | strapping | adc · touch · spi | |
| 8 | 13 | MOSIA10T4PWM | strapping | adc · touch · spi | |
| 9 | 14 | SCKA8T6PWM | strapping | adc · touch · spi | |
| 10 | 15 | A3T3PWM | strapping | adc · touch | |
| 11 | 19 | SCL1PWM | safe | - | |
| 12 | 22 | SDA1PWM | safe | - | |
| 13 | 25 | A1DAC1PWM | safe | adc · dac | |
| 14 | 26 | A0DAC2PWM | safe | adc · dac | |
| 15 | 27 | SSA2T7PWM | safe | adc · touch · spi | |
| 16 | 32 | TXTX1A6T9PWM | uart | adc · touch · uart | |
| 17 | 33 | SCLA5T8PWM | safe | adc · touch · i2c |
Start with these
8 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
7 pins · 7 things to knowBUTTONGPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping
Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.
WIRE1_PIN_DEFINEDGPIO1 Default UART0 TX pin for USB-serial programming and console. UART
Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.
PIN_NEOPIXELGPIO5 Bootstrapping pin; internal pull-up; VSPI CS0 (default SPI chip-select); acts as FSPIWP (flash write-protect) on internal-flash variants. Strapping
Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.
MISOGPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping
Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.
MOSIGPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG
Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.
SCKGPIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG
Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.
A3GPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping
Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.
Only if you know the tricks
2 pins · 1 thing to knowRXGPIO7NEOPIXEL_POWERGPIO8 SPI flash data lines SD0 and SD1 Flash
Used for internal flash/PSRAM data; not available for general GPIO.
- RXConnected to SPI flash data 0 (SD0).
- NEOPIXEL_POWERConnected to SPI flash data 1 (SD1).
All 17 pins on the Adafruit QT Py ESP32 are usable GPIO, spaced at the standard 2.54 mm pitch.
Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO4 and SCL on GPIO33; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO32 and GPIO7 cover serial logging and flashing.
Beyond plain digital I/O you get 11 ADC-capable pins for sensors and battery monitoring, 8 capacitive-touch inputs and 2 true DAC outputs.
7 of the exposed pins carry boot-time or system duties on the ESP32 (BUTTON, WIRE1_PIN_DEFINED, PIN_NEOPIXEL and 4 more) - check the guidance above before wiring anything to them. SDA, SCL1, SDA1, A1 and 4 more are free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32 Wrover Module Flash Size: 8MB (64Mb) Flash Mode: DIO PSRAM: QSPI PSRAM Partition Scheme: 8M with spiffs (3MB 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_qtpy_esp32_pico]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_qspi
build_flags = -DBOARD_HAS_PSRAMesp32dev - or type it after board =.esp32:
board: esp32dev
variant: esp32
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_outesp32dev (same ids as PlatformIO).esptool.py --chip esp32 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32 · 22 × 17.9 mm · vs other ESP32 chips →Dimensions
About this board
At 22 × 17.9 mm it's among the smallest boards in the whole ESP32 family.
Inside sits the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
At $14.95 it's cheaper than most ESP32 boards, which usually run around $20.
The small footprint costs pins: 17 GPIO are broken out, versus 24 or so on a full-size board.
Around the module: 2MB (QSPI) PSRAM, a STEMMA QT connector, an addressable RGB LED (GPIO5) and Reset/Boot buttons.
Where to buy
prices are typical street pricesResources
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