SparkFun Auto pHAT for Raspberry Pi

Jargon buster

Plain-language definitions for the technical terms used above.

DC

DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.

encoder

An encoder is a sensor that converts the rotation or position of a shaft, knob or dial into electrical signals, reporting movement as incremental steps and direction, or as an absolute position. It is used to track how far something has turned, which matters for precise positioning, speed control, repeatable movement, or using a rotary knob as an input.

FSR

FSR usually means full-scale range, the total span between the lowest and highest value a converter can output or measure, so error figures quoted as a percentage of FSR depend on the selected range such as 2.5 V or 5 V. In other contexts FSR can instead mean a force-sensing resistor, a component whose resistance changes with applied pressure, so check which sense is meant.

GPIO

General-purpose input/output pins are microcontroller pins you can set in software to read signals, switch devices on and off, or connect to peripherals. The number of GPIO pins matters because it limits how many buttons, LEDs, sensors, and other parts you can wire directly to the board.

Gyroscope

A gyroscope measures rotation, such as how fast a board is turning around its X, Y, and Z axes. This matters for projects like gesture controls, balancing robots, and motion tracking where tilt or rotation changes need to be detected.

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.

ICM-20948

A motion-sensing chip that combines accelerometer, gyroscope, and magnetometer measurements. The part number matters because it tells you the board can provide 9-axis orientation and movement data, and which software libraries or drivers are likely to work.

IMU

An IMU (Inertial Measurement Unit) combines motion sensors, typically an accelerometer and gyroscope and sometimes a magnetometer, to measure movement and orientation. It can sense motion, tilt, vibration, rotation, and changes in direction, which is useful for tasks such as navigation, stabilisation, gesture detection, and asset tracking.

magnetometer

A sensor that measures magnetic fields, often used to work out compass direction. It matters because nearby magnets, motors, or metal objects can affect readings and may require calibration.

motor driver

An electronic circuit that lets a low-power controller switch and control a motor that needs more current than the controller pins can safely provide. Checking motor driver support matters because pumps and motors usually cannot be connected directly to a microcontroller output.

NVIDIA Jetson Nano

The NVIDIA Jetson Nano is a compact NVIDIA computing module used for camera, robotics and machine-learning projects at the edge. A compatible carrier board can host the module, though the module itself is usually sold separately.

pHAT

A smaller add-on board format for Raspberry Pi, similar in idea to a HAT but usually not full-sized. It matters because pHAT compatibility can affect how neatly a board stacks or fits into a Raspberry Pi project.

PWM

Pulse Width Modulation is a way for a digital pin to simulate variable output power by switching on and off very quickly. It matters for controlling things like LED brightness, motor speed, or servo-style signals from a microcontroller pin.

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.

servo

A servo is a motor with built-in position control, usually told to move to a specific angle by a control signal. It matters when you need repeatable movement, such as steering, arms, flaps, or linkages, rather than continuous spinning.

USB-C

USB-C is a small, reversible USB connector that can carry power, data and, on some devices, video over a single cable. The same connector can range from charging only to high-speed data, so the functions a given port actually supports vary.