On the end of the board opposite the USB connector is the STEMMA QT connector. This allows you to use a STEMMA QT cable to connect up any STEMMA QT-capable sensor or breakout to quickly get started with no soldering necessary. The Trinkey QT2040 board is the same size as most of the QT-capable breakouts Adafruit makes, with the mounting holes in the same place so you can mount the sensor breakout right on top of the board!

In CircuitPython, you can use the STEMMA connector with board.SCL and board.SDA, or board.STEMMA_I2C().

The big square in the center of the board is the RP2040 microcontroller. This is the brain of the board.

The little square between the RP2040 and the USB connector is the 8MB QSPI Flash.

QSPI is neat because it allows you to have 4 data in/out lines instead of just SPI's single line in and single line out. This means that QSPI is at least 4 times faster. But in reality is at least 10x faster because you can clock the QSPI peripheral much faster than a plain SPI peripheral. In CircuitPython, the QSPI flash is used natively by the interpreter and is read-only to user code, instead the flash just shows up as the writable disk drive!

On the top edge of the board, towards the STEMMA QT end, is the reset button (labeled RST on the silk). Tap once to reset the board. When combined with the boot button, the reset button allows the board to enter the bootloader.

On the bottom edge of the board, towards the STEMMA QT end, is the boot button (labeled BOOT on the silk). When combined with the reset button, the boot button allows you to enter the bootloader.

This button is also usable as an input in CircuitPython at board.BUTTON.

Near the corner of the RP2040, along the same edge as the reset button, is the RGB NeoPixel LED. In CircuitPython, it is used as a status LED, and can be controlled in user code at board.NEOPIXEL.