Adafruit SEN54 or SEN55 Adapter Breakout - STEMMA QT / Qwiic

Jargon buster

Plain-language definitions for the technical terms used above.

boost converter

A boost converter is a power circuit that raises a lower input voltage to a higher output voltage. It matters here because the board can power a sensor that needs a higher supply voltage while still using a single connector for power and data.

breakout

A breakout is a small circuit board that makes a tiny or hard-to-solder component easier to connect to with standard pins. It matters because this OLED module can be wired into a microcontroller project without needing to solder directly to the display’s fine contacts.

I2C

I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.

Matter

A smart home connectivity standard designed to let devices work across different ecosystems. It matters if you want a project to integrate more easily with platforms such as Apple Home, Google Home, or other Matter-compatible systems.

microcontroller

A microcontroller is a small computer on a chip that runs your program and controls connected inputs and outputs. For this product, it is the part that reads buttons and sensors, drives the display and speaker, and communicates over Bluetooth.

NOx

NOx means nitrogen oxides, a group of gases often linked to combustion sources such as gas stoves, heaters, and vehicle exhaust. A NOx index can help show changes in indoor air quality, especially where combustion or outdoor pollution may affect the room.

particulate matter

Particulate matter means tiny particles suspended in the air, such as dust, smoke, pollen, or pollution. A sensor that measures it is useful for air-quality projects because particle levels can affect comfort and health.

PM10

PM10 refers to airborne particles with a diameter of about 10 micrometres or smaller. It includes larger dust and pollen-like particles, so it is useful for detecting coarser airborne pollution.

PM2.5

PM2.5 refers to airborne particles with a diameter of about 2.5 micrometres or smaller. It is a common air-quality measurement because these fine particles can be breathed deep into the lungs.

PM4

PM4 refers to airborne particles with a diameter of about 4 micrometres or smaller. It gives another particle-size category, which can help compare different dust, smoke, or indoor pollution sources.

Qwiic

Qwiic is a plug-in connector system for I2C devices that uses small 4-pin cables, so you can connect compatible sensors without soldering. It matters because your controller or adapter also needs Qwiic, or you will need a cable or breakout to wire it up.

SEN55

A Sensirion environmental sensor module that measures particulate matter, VOC-related air quality, NOx-related air quality, temperature, and humidity. The part number matters because it tells you this board can report several indoor air-quality readings from one sensing module.

single-board computer

A complete computer built onto one circuit board, usually including the processor, memory, ports, and connectors. This matters because accessories like heatsinks must match the board’s layout and mounting holes to fit properly.

STEMMA

A plug-and-cable connection system used on some maker electronics boards to make wiring simpler. If a product uses STEMMA, you need the matching cable or connector type to plug it in without soldering.

STEMMA QT

A small plug-in connector system for I2C boards that lets you connect compatible sensors and controllers without soldering. It matters because it can make wiring faster and less error-prone, especially when adding several small modules to a project.

VOC

Volatile organic compounds are gases released from things like paints, cleaners, smoke, and some plastics. A VOC reading helps indicate indoor air quality, but it is usually an index or estimate rather than a direct identification of each chemical.