Adafruit QT Py - SAMD21 Dev Board with STEMMA QT

CAD model © Adafruit Industries, MIT licensed, MIT License

What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with our favorite lil chip, the SAMD21 (as made famous in our GEMMA M0 and Trinket M0 boards).

3V
Regulated 3.3 V output from the onboard regulator; Adafruit Learn says it can supply about 500 mA.
Type · powerVoltage · 3.3V regulated output
5V
5 V from the USB port; can be used as a voltage input only with a diode as described by Adafruit Learn.
Type · powerVoltage · 5V USB rail
GND
Power, data, and signal ground.
Type · groundVoltage · 0V
A0 / D0
Digital/analogue GPIO 0; true 10-bit analogue output and capacitive touch input; no PWM.
Type · gpioVoltage · 3.3V logic
A1 / D1
Digital/analogue GPIO 1; capacitive touch input or AREF pin.
Type · gpioVoltage · 3.3V logic

Start wiring

I2C · UART · SPI · 3.3V regulated output · 5V USB rail

Confirm the data interface matches your host board.

Module pins: 3V, 5V, GND, A0 / D0, A1 / D1, A2 / D2, A3 / D3, SDA / D4. Schematik maps them to your board in the app.

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Pin	Type	Function	Voltage
3V	power	Regulated 3.3 V output from the onboard regulator; Adafruit Learn says it can supply about 500 mA.	3.3V regulated output
5V	power	5 V from the USB port; can be used as a voltage input only with a diode as described by Adafruit Learn.	5V USB rail
GND	ground	Power, data, and signal ground.	0V
A0 / D0	gpio	Digital/analogue GPIO 0; true 10-bit analogue output and capacitive touch input; no PWM.	3.3V logic
A1 / D1	gpio	Digital/analogue GPIO 1; capacitive touch input or AREF pin.	3.3V logic
A2 / D2	gpio	Digital/analogue GPIO 2; PWM-capable and capacitive touch input.	3.3V logic
A3 / D3	gpio	Digital/analogue GPIO 3; PWM-capable and capacitive touch input.	3.3V logic
SDA / D4	i2c	I2C data and digital pin 4; PWM-capable, no analogue input. STEMMA QT uses this SDA signal.	3.3V logic
SCL / D5	i2c	I2C clock and digital pin 5; PWM-capable, no analogue input. STEMMA QT uses this SCL signal.	3.3V logic
TX / A6 / D6	uart	Serial1 transmit output; also analogue/digital GPIO 6, PWM-capable and capacitive touch input.	3.3V logic
RX / A7 / D7	uart	Serial1 receive input; also analogue/digital GPIO 7, PWM-capable and capacitive touch input.	3.3V logic
SCK / A8 / D8	spi	Hardware SPI clock; also analogue/digital GPIO 8 and PWM-capable output.	3.3V logic
MI / A9 / D9	spi	Hardware SPI MISO, microcontroller-in serial-out; also analogue/digital GPIO 9 and PWM-capable output.	3.3V logic
MO / A10 / D10	spi	Hardware SPI MOSI, microcontroller-out serial-in; also analogue/digital GPIO 10 and PWM-capable output.	3.3V logic
NeoPixel / D11	gpio	Onboard NeoPixel signal pin, connected to digital pin 11.	3.3V logic
NeoPixel power / D12	gpio	Onboard NeoPixel power control; Adafruit Learn says set pin 12 low to turn off the pixel for low power usage.	3.3V logic
STEMMA QT	connector	Plug-and-play I2C connector using the board SCL and SDA signals for STEMMA QT/Qwiic accessories.	3.3V I2C connector

Pinout

Start wiring

Connectors

Displays

Air quality

MCUs and boards