# Adafruit QT Py SAMD21
## Overview
What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with our favorite li'l chip, the SAMD21 (as made famous in our GEMMA M0 and Trinket M0 boards).
This time it comes with [our favorite connector - the STEMMA QT](http://adafruit.com/stemma), a chainable I2C port that can be used with [any of our STEMMA QT sensors and accessories](https://www.adafruit.com/category/620).
[OLEDs](https://www.adafruit.com/?q=qt+oled&main_page=category&cPath=1005&sort=BestMatch)! [Inertial Measurment Units](https://www.adafruit.com/?q=qt+imu&main_page=category&cPath=1005&sort=BestMatch)! [Sensors a-plenty](https://www.adafruit.com/?q=qt+sensor&main_page=category&cPath=1005&sort=BestMatch). All plug-and-play thanks to the innovative chainable design: [SparkFun Qwiic](https://www.sparkfun.com/qwiic)-compatible [STEMMA QT](https://learn.adafruit.com/introducing-adafruit-stemma-qt) connectors for the I2C bus so you don't even need to solder! Just plug in a compatible cable and attach it to your MCU of choice, and you’re ready to load up some software and measure some light.
Use any [SparkFun Qwiic](http://www.sparkfun.com/qwiic) boards! [Seeed Grove I2C boards](https://www.adafruit.com/product/4528) will also work with an adapter cable.
The pinout and shape is [Seeed Xiao](https://wiki.seeedstudio.com/Seeeduino-XIAO/) compatible, with castellated pads so you can solder it flat to a PCB. In addition to the QT connector, we also added an **RGB NeoPixel** (with controllable power pin to allow for ultra-low-power usage), **and a reset button** (great for restarting your program, or entering the bootloader).
Runs Arduino like a dream, and can be used for basic CircuitPython projects. For more advanced usage like datalogging or file storage, solder an SOIC SPI flash chip onto the bottom pads.
- Same size, form-factor, and pin-out as Seeed Xiao
- **ATSAMD21E18** 32-bit Cortex M0+ - 48 MHz 32 bit processor with **256KB Flash** and **32 KB RAM**
- Native USB supported by every OS - can be used in Arduino or CircuitPython as USB serial console, MIDI, Keyboard/Mouse HID, even a little disk drive for storing Python scripts.
- Can be used with **Arduino IDE** or **CircuitPython**
- **Built in RGB NeoPixel LED**
- **11 GPIO pins:**
- True analog output on one I/O pin - can be used to play 10-bit quality audio clips in Arduino (CircuitPython does not have storage for audio clips)
- 9 x 12-bit analog inputs (SDA/SCL do not have analog inputs)
- 1 x Optional AREF on A1
- 9 x PWM outputs (A0 is analog out, A1 is not PWM capable)
- Hardware I2C port with STEMMA QT plug-n-play connector
- Hardware UART
- Hardware SPI
- Hardware I2S
- 6 x Capacitive Touch with no additional components required
- 3.3V regulator with [**600mA peak output**](https://www.diodes.com/assets/Datasheets/AP2112.pdf)
- [Optional SOIC-8 SPI Flash chip on bottom](https://www.adafruit.com/product/4763)
- **Reset switch ** for starting your project code over or entering bootloader mode
- **USB Type C connector**
- **Really, really small**
- [Next Page](https://learn.adafruit.com/adafruit-qt-py/update-the-uf2-bootloader.md)
## Primary Products
### Adafruit QT Py - SAMD21 Dev Board with STEMMA QT
[Adafruit QT Py - SAMD21 Dev Board with STEMMA QT](https://www.adafruit.com/product/4600)
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).
This time it comes with [our favorite connector - the STEMMA QT](http://adafruit.com/stemma), a chainable I2C...
In Stock
[Buy Now](https://www.adafruit.com/product/4600)
[Related Guides to the Product](https://learn.adafruit.com/products/4600/guides)
## Featured Products
### STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long
[STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long](https://www.adafruit.com/product/4210)
This 4-wire cable is a little over 100mm / 4" long and fitted with JST-SH female 4-pin connectors on both ends. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove.
In Stock
[Buy Now](https://www.adafruit.com/product/4210)
[Related Guides to the Product](https://learn.adafruit.com/products/4210/guides)
### STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long
[STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long](https://www.adafruit.com/product/4399)
This 4-wire cable is 50mm / 1.9" long and fitted with JST SH female 4-pin connectors on both ends. Compared with the chunkier JST PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove.
Out of Stock
[Buy Now](https://www.adafruit.com/product/4399)
[Related Guides to the Product](https://learn.adafruit.com/products/4399/guides)
### STEMMA QT / Qwiic JST SH 4-Pin Cable - 200mm Long
[STEMMA QT / Qwiic JST SH 4-Pin Cable - 200mm Long](https://www.adafruit.com/product/4401)
This 4-wire cable is a little over 200mm / 7.8" long and fitted with JST-SH female 4-pin connectors on both ends. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove.
Out of Stock
[Buy Now](https://www.adafruit.com/product/4401)
[Related Guides to the Product](https://learn.adafruit.com/products/4401/guides)
### USB Type C Cable with Data/Charge Switch
[USB Type C Cable with Data/Charge Switch](https://www.adafruit.com/product/4696)
Perhaps your smart phone, tablet, or even your Raspberry Pi 4, charges off of USB, but can you really trust that charging station at the airport? Now you can control when to allow data in or out of your device with this specially-designed USB cable._Voila!_ Your cable's data...
In Stock
[Buy Now](https://www.adafruit.com/product/4696)
[Related Guides to the Product](https://learn.adafruit.com/products/4696/guides)
### USB Type A to Type C Cable - 6" long
[USB Type A to Type C Cable - 6" long](https://www.adafruit.com/product/4472)
As technology changes and adapts, so does Adafruit. This **USB Type A to Type C** cable will help you with the transition to USB C, even if you're still totin' around a USB Type A hub, computer or laptop.
USB C is the latest industry-standard connector for...
In Stock
[Buy Now](https://www.adafruit.com/product/4472)
[Related Guides to the Product](https://learn.adafruit.com/products/4472/guides)
### USB Type A to Type C Cable - 1ft - 0.3 meter
[USB Type A to Type C Cable - 1ft - 0.3 meter](https://www.adafruit.com/product/4473)
As technology changes and adapts, so does Adafruit. This **USB Type A to Type C** cable will help you with the transition to USB C, even if you're still totin' around a USB Type A hub, computer or laptop.
USB C is the latest industry-standard connector for...
In Stock
[Buy Now](https://www.adafruit.com/product/4473)
[Related Guides to the Product](https://learn.adafruit.com/products/4473/guides)
### USB Type A to Type C Cable - approx 1 meter / 3 ft long
[USB Type A to Type C Cable - approx 1 meter / 3 ft long](https://www.adafruit.com/product/4474)
As technology changes and adapts, so does Adafruit. This **USB Type A to Type C** cable will help you with the transition to USB C, even if you're still totin' around a USB Type A hub, computer or laptop.
USB C is the latest industry-standard connector for...
In Stock
[Buy Now](https://www.adafruit.com/product/4474)
[Related Guides to the Product](https://learn.adafruit.com/products/4474/guides)
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