M-DUINO PLC Arduino Ethernet 19R I/Os (Relay Output)

Jargon buster

Plain-language definitions for the technical terms used above.

Bootloader

Small starter software on a microcontroller that lets new code be uploaded before the main program runs. Knowing how to enter bootloader mode matters when you need to program the board or recover it after a faulty sketch.

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.

Flash memory

Flash memory is non-volatile memory that retains stored data even when power is removed, and can be erased and rewritten in blocks. It lets data such as firmware, settings or saved records persist across power cycles.

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.

IDE

Short for Integrated Development Environment, a program used to write, run and manage code. It matters because some learners prefer a traditional coding workspace instead of a guided notebook-style lesson.

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.

RS485

RS485 is a robust differential serial communication standard often used in factories, farms and buildings where cables may be long or electrically noisy, and it can link many devices on a single pair of wires. When a product lists RS485, it can communicate with industrial sensors, meters and control equipment over longer distances than typical hobby serial wiring.

RX

RX means receive, usually showing data being received by the board. An RX indicator LED can help with troubleshooting USB or serial communication.

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.

SRAM

Fast temporary memory used by a processor while a program is running. More SRAM helps with projects that handle larger data buffers, networking, displays, or more complex code.

TX

TX means transmit, usually showing data being sent from the board. A TX indicator LED can help you see when the board is communicating or uploading code.

UART

UART is a simple asynchronous serial interface that sends data over separate transmit and receive wires, usually labelled TX and RX, with both ends set to the same baud rate. It is a common way for microcontrollers and other serial devices to exchange data.