Teensy 4.1 Lockable Without Ethernet

Jargon buster

Plain-language definitions for the technical terms used above.

baud

Baud is the signalling rate of a serial connection, often used as the speed setting for UART communication. Matching the baud rate matters because both connected devices must use the same setting for readable data.

CAN bus

CAN bus is a reliable two-wire communication network originally designed for vehicles and now common in machinery and robotics. It matters when you need multiple controllers or devices to share status and control messages in a noisy electrical environment.

EEPROM

A type of non-volatile memory that keeps stored data even when power is turned off. In a sensor module, it can be used to store settings or calibration data so they do not need to be re-entered every time.

FIFO

FIFO stands for “first in, first out” and is a small memory buffer inside the sensor that stores recent readings in order. This matters because it can help capture motion data without the microcontroller needing to read the sensor every single instant.

FPU

A floating-point unit is hardware inside a processor that speeds up calculations with decimal numbers. This helps when projects use maths-heavy tasks such as motion sensing, filtering sensor readings, or audio processing.

Headers

Rows of metal pins used to plug a module into a breadboard or connect it with jumper wires. Pre-soldered headers make the module easier to use straight away without needing to solder the pins yourself.

I2S

I2S is a digital audio interface used to send sound data between chips, such as from a microcontroller to an audio amplifier or DAC. It matters if your project needs cleaner digital audio output than a basic buzzer or PWM signal can provide.

JTAG

JTAG is a hardware debugging and programming interface used to inspect and control chips at a low level. It matters for advanced development because it can help diagnose firmware problems that are hard to see through normal serial output.

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.

microSD card

A microSD card is a small removable memory card used to store files such as audio tracks. For this product, the card is where the sound files live, so its capacity and formatting can affect how many sounds you can use.

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.

RAM

RAM is temporary memory used while a device is running, and its contents are lost when power is removed. A “Run in RAM” mode is useful for testing settings without permanently programming the module, but it may not support every feature.

RTC

A Real-Time Clock keeps track of time even when the main processor is asleep or powered down, usually with a small backup battery. It matters for data logging and tracking projects that need accurate timestamps.

SPI

A fast serial communication bus often used for displays, memory cards, and sensors. It matters because SPI devices need specific pins for clock and data, plus a separate chip-select line for each device.

USB host

A USB host is the side of a USB connection that controls attached devices, like a computer talking to a keyboard or flash drive. This matters because most microcontroller boards are normally USB devices, so adding USB host support lets them use common USB peripherals.