Banana Pi - router BPi-R1

Jargon buster

Plain-language definitions for the technical terms used above.

ADC

An analogue-to-digital converter reads a changing voltage and turns it into a number the microcontroller can use. It matters when connecting analogue sensors such as light, sound, or variable-resistor sensors.

CLK

CLK is a clock line that times when bits are sent and read on a synchronous serial bus such as SPI. Any device using a clock line must have its CLK connected to the controller's clock output so the two stay in step while data is transferred.

CS

CS stands for chip select, a control pin used by SPI devices to tell which connected device should listen. It matters when you connect more than one SPI module to the same microcontroller, because each device usually needs its own CS pin.

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.

DSI

DSI stands for Display Serial Interface, a high-speed connection commonly used to send video data from a computer board to a display. It matters because DSI signals are not simple GPIO wires, so the cable, connector, and signal routing need to match the display interface.

GND

GND is the ground or reference connection (0 V) for a circuit. When connecting two devices together, their grounds must be joined so both agree on what counts as a low or high signal.

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.

HDMI

HDMI is a common digital video and audio connection used by computers, media players, and many displays. If a display kit has HDMI input, it is usually much easier to test with a single-board computer because it can act like a normal monitor.

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.

LED

A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.

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.

RGB

Short for red, green and blue, the three primary colours of light that are mixed in varying amounts to make a wide range of colours. In electronics RGB can refer to an LED or pixel that blends these three colours, or to a colour signal or interface that carries separate red, green and blue channels.

RJ45

The common plug and socket style used for wired Ethernet network cables. If a board has an RJ45 connector, you can usually plug it into standard Ethernet cabling without making a custom connector.

RX

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

SDA

The data line used by the I2C bus to carry information between a controller and connected devices. When wiring I2C, SDA must be connected to the SDA pin on every device sharing the bus.

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.

Thread

A low-power wireless mesh networking standard designed for smart home and IoT devices. It matters because Thread devices can relay messages through each other, helping build reliable networks for sensors and controllers.

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.

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.

VCC

VCC is the positive power-supply connection on a chip or module. Connecting it to the correct supply voltage is needed for the part to power on and helps avoid damaging the electronics.