GPS-RTK Board - NEO-M8P-2 (Qwiic)

Jargon buster

Plain-language definitions for the technical terms used above.

3.3V TTL

3.3V TTL means the serial logic signals use 3.3 volt levels rather than 5 volts. This matters because connecting it directly to a 5V-only signal can damage the module or cause unreliable communication unless level shifting is used.

breakout

A breakout board carries a small or fine-pitched component and brings its connections out to standard, breadboard- and header-friendly pins. Describing a part as a breakout means it can be wired into a project without soldering directly to the component's tiny contacts.

COM port

A COM port is how a computer (chiefly under Windows) presents a serial port to software, whether a physical RS-232 port or a virtual port created when a USB-to-serial device is plugged in. Software can then communicate with the connected device over serial using a terminal or configuration program.

GNSS

GNSS stands for Global Navigation Satellite System, an umbrella term for satellite positioning networks such as GPS, GLONASS, Galileo and BeiDou. Receivers use these satellites to determine position, and high-precision units can output a steady stream of serial position data.

GPS

The US satellite navigation system used by GNSS receivers to calculate position and time. Support for GPS is important because it is widely available and often used together with other constellations for more reliable positioning.

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.

I2C address

An I2C address is the number a device uses so a microcontroller can tell it apart from other devices on the same I2C bus. It matters because two devices with the same fixed address may conflict if used together.

multiplexer

A multiplexer (mux) is a chip or circuit that selects one of several input signals and routes it to a single shared output, with select lines choosing which input is connected; running the same idea in reverse, to send one input to a chosen output, gives a demultiplexer. Multiplexers let a single controller or line work with several signals or devices that would otherwise clash on a shared connection.

NEO-M8P-2

A u-blox GNSS receiver module that supports high-precision RTK positioning. The exact module matters because it determines the board’s accuracy, update rates, supported interfaces, and whether it can work as a rover or base station.

PVT

Position, velocity and time data reported by a GNSS receiver. Knowing the PVT update rate helps you judge how often the board can provide basic navigation information to your project.

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.

RTCM 3.x

RTCM 3.x is a standard data format used to send GNSS correction information from a base station to a rover. It matters because both ends of an RTK setup need to understand the correction format to achieve high-accuracy positioning.

RTK

Real-Time Kinematic positioning is a GNSS technique that uses correction data from a base station to greatly improve location accuracy. It matters if you need centimetre-level positioning for robotics, mapping, surveying, or tracking rather than ordinary metre-level GPS accuracy.

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.

Survey-in mode

Survey-in mode is a GNSS base-station setup process in which a receiver averages its own position over a set period to establish a fixed reference location. A receiver that supports survey-in can act as an RTK base and generate correction data for one or more rover receivers.

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.

UBX binary protocol

UBX is u-blox’s binary communication protocol for sending configuration commands and receiving detailed navigation data. It matters when you want faster, more compact, or more complete data than standard text-based GPS messages can provide.