NEO-M9N GPS Breakout Board

Product Description

Intended for automotive and industrial applications, the NEO-M9N GNSS receiver provides excellent sensitivity and acquisition times. With a SMA connected external antenna, this Breakout Board GPS receiver provides support for up to four GNSS constellations. Additionally, the NEO-M9N detects and reports jamming and spoofing events while also using advanced filtering algorithms to minimize RF interference. The NEO-M9N Breakout Board also includes an integrated rechargeable battery provides backup power for maintaining satellite almanac data and enabling rapid hot starts. Getting started is easy with u-blox u-center configuration software.

Key Features

• Multi-constellation GNSS support: Compatible with GPS L1 C/A, GLONASS L1OF, Galileo E1B/C, and BeiDou B1I
• High accuracy: 2.0m horizontal position accuracy (CEP)
• Fast acquisition: Cold start time-to-fix of 24 seconds, hot start of 2 seconds
• High update rates: Max 25Hz with one GNSS constellation, max 5Hz with four GNSS
• Low power consumption: 23mA tracking (continuous), 8mA tracking (power save mode)
• External antenna connector: SMA connector for improved performance with external antennas
• Backup battery: 3V, 1.5 mAh rechargeable battery provides backup power for hot start capability
• Easy Communication: USB, UART, I²C, and SPI interface options
• 6 pin 1mm pitch connector Easy 5V tolerant I²C, UART, or SPI connection without soldering
• Easy Communication: USB, UART, I²C, and SPI interface options
• 6 pin 1mm pitch connector Easy 5V tolerant I²C, UART, or SPI connection without soldering
• 3.3V or 5V operation: Compatible with modern microcontrollers
• Compact size: Standard Qwiic board form factor
• High altitude/velocity: Max altitude 80,000m, max velocity 500m/s
• Precise timing: Time pulse accuracy of 30ns (RMS)
• Advanced features: Dead reckoning, spoofing detection, jamming indication
• Lead-Free
• Designed and assembled in the USA

The NEO-M9N is designed for applications requiring high accuracy and reliability. Whether you’re building precision agriculture equipment, surveying instruments, or autonomous vehicle navigation systems, the NEO-M9N delivers professional-grade positioning performance.

NEO-M9N Includes two onboard LEDs. The LED labeled PWR lights up when power is connected. The LED labeled PPS flashes with a PPS signal when the NEO-M9N has a PPS signal.

Pinout

Pin	I/O	Description
3V3	O	3.3V Direct Chip Power Supply Output
GND	-	Ground
RX	I	UART Receive (5V tolerant logic), SPI MOSI
TX	O	UART Transmit (5V tolerant logic), SPI MISO
VCC	I	Power Supply Input (3.3V-5V)
PPS	O	Time Pulse Output (1Hz default)
RESET	I	Reset Input (active low)
SAFE	I	Safe Boot Input (active low)
INT	O	Interrupt Output (configurable)
SDA	I/O	I²C Data (5V tolerant logic), SPI CS
SCL	I	I²C Clock (5V tolerant logic), SPI SCK

Jumpers

The NEO-M9N breakout board includes a number of jumpers for configuration. First there are two jumpers for enabling the PPS and PWR LEDs. These jumpers allow you to disable the LEDs to reduce power consumption in battery-powered applications. To disable the LEDs cut the jumpers labeled for each LED (PPS or PWR). Next, There are serveral jumpers to configure for I2C/UART and SPI communication. To use I2C, connect the I2C pullup jumpers and ensure the D_SEL jumper is disconnected. To use SPI, disconnect I2C pullup jumpers and connect the D_SEL jumper. To use UART, disconnect the D_SEL jumper. See image for jumper identification:

The NEO-M9N Breakout Board operates between 3V and 5V. All I/O pins operate at 3.3V logic levels, however the board also has some 5V compatibility.

Power Supply

• Power Input (VCC): 3.3V - 5V (onboard regulator provides 3.3V to the module)
• Logic Levels: 3.3V output levels on all pins

5V System Compatibility

5V Tolerant Pins (safe to connect to 5V Arduino):

• VCC (power input)
• SDA (I²C data,SPI Chip CS)
• SCL (I²C clock,SPI SCK)
• TX (UART transmit,SPI MISO)
• RX (UART receive,SPI MOSI)

NOT 5V Tolerant (use level shifter or voltage divider):

• INT (interrupt pin)
• SAFE (safe boot pin)
• RST (reset pin)

Arduino Compatibility

The NEO-M9N can be connected directly to 5V Arduino boards for basic I²C, UART, and SPI communication. However, avoid connecting 5V signals to the INT, SAFE, and RST pins to prevent damage.

Communication Interfaces

I²C Communication

The NEO-M9N supports I²C communication as the primary interface:

• I²C Address: 0x42 (fixed address)
• Clock Speed: Standard 100 kHz and Fast Mode 400 kHz
• Pull-up Resistors: Onboard 2.2kΩ pull-ups included
• Connector: 6-pin 1mm pitch JST connector for I²C, UART, and SPI

SPI Communication

The NEO-M9N also supports SPI communication:

• Clock Speed: Maximum clock speed of 5.5 MHz, for a max transfer rate of 125 kB/s
• Pinout: See pinout section for pin definition
• Connector: 6-pin 1mm pitch JST connector for I²C, UART, and SPI

UART Communication

The NEO-M9N also supports UART communication:

• Default Baud Rate: 38,400 bps (configurable via u-center2)
• Data Format: 8 data bits, no parity, 1 stop bit
• Protocol: Standard NMEA 0183 and u-blox UBX binary protocols
• Connector: 6-pin 1mm pitch JST connector for I²C, UART, and SPI

Backup Battery

The board includes a rechargeable backup battery that:

• Maintains satellite orbital data when main power is removed
• Provides backup operation to maintain hot start capability
• Enables faster time-to-fix (2-second hot start)
• Automatically recharges when main power is applied

External Antenna Support

SMA Connector

The NEO-M9N features a SMA connector for external antenna connection:

• Connector Type: SMA
• Impedance: 50Ω
• Frequency Range: L1 band (1575.42 MHz ±1.023 MHz)
• Applications: Improved performance in challenging environments

Antenna Options

• Active antennas: GPS/GNSS antennas with built-in LNA (Low Noise Amplifier)
• Passive antennas: Simple patch or helical antennas for basic applications
• Multi-band antennas: Support for multiple GNSS frequencies
• High-gain antennas: For applications requiring maximum sensitivity

Antenna Selection

For best performance, use a quality GPS/GNSS antenna designed for L1 band operation. Active antennas typically provide better performance in challenging signal environments.

Software Libraries and Examples

Arduino Library

SparkFun u-blox GNSS Arduino Library v3

Full featured Arduino library for u-blox GNSS modules:

• Installation: Available through Arduino Library Manager
• Repository: SparkFun u-blox GNSS v3
• Features: Complete UBX protocol support, NMEA parsing, configuration tools

Platform Support

• Arduino: Full support with SparkFun library
• Raspberry Pi: Compatible via I²C, UART, and SPI interfaces
• ESP32/ESP8266: Full compatibility with Arduino libraries
• STM32: Compatible via I²C, UART, and SPI
• Python: Support through pyubx2 and other GNSS libraries

Configuration Software

u-center2 (Recommended)

• Official u-blox configuration software for Windows
• Download: u-blox u-center2
• Features: Complete module configuration, real-time monitoring, logging

Software Compatibility

Use u-center2 with the NEO-M9N for best compatibility and access to all M9 platform features.

Advanced Features

Anti-Jamming and Spoofing Detection

• Jamming Indication: Detects and reports RF interference
• Spoofing Detection: Identifies potentially false GNSS signals
• Signal Integrity: Advanced algorithms ensure position reliability

Configurable Options

The NEO-M9N supports extensive configuration via u-center2 or Arduino library:

• Update rates: 1Hz to 25Hz (depending on constellation count)
• GNSS constellation selection: Enable/disable specific satellite systems
• Power modes: Continuous or power save modes
• Message output: Configure NMEA and UBX message types
• Time pulse configuration: Customizable PPS output timing
• Geofencing: Define virtual boundaries with alerts

Time Pulse (PPS) Output

The PPS pin provides a precise timing signal:

• Default: 1Hz square wave synchronized to GPS time
• Accuracy: 30ns RMS timing accuracy
• Configurable: Frequency and pulse width adjustable via software
• Applications: Network synchronization, precise timing systems

Helpful Notes

• External antenna required - The NEO-M9N requires an external antenna connected to the SMA connector
• Allow warm-up time - First fix may take several minutes, subsequent fixes are much faster
• Backup battery maintenance - The rechargeable battery maintains hot start capability
• Power supply stability - Ensure clean, stable power for best performance
• Antenna placement - Position antenna with clear sky view for optimal performance
• Configuration persistence - Settings configured via u-center2 are stored in non-volatile memory

Datasheets and Documentation

Schematic:

• NEO-M9N Breakout Board Schematic

Chip Info and Product Datasheets:

• u-blox NEO-M9N Datasheet
• u-blox NEO-M9N Integration Manual
• u-blox NEO-M9N Product Summary
• u-blox NEO-M9N Product Page

FAQ

Q: What’s the difference between NEO-M9N and SAM-M10Q?

A: The NEO-M9N is from the M9 platform with focus on professional applications and external antenna support. The SAM-M10Q is from the newer M10 platform with lower power consumption and built-in chip antenna.

Q: Do I need an external antenna?

A: The NEO-M9N requires an external antenna connected to the SMA connector. It does not have a built-in chip antenna like the SAM-M10Q.

Q: How accurate is the NEO-M9N?

A: The NEO-M9N provides 2.0m horizontal position accuracy under normal conditions.

Q: Can I use this module indoors?

A: GPS/GNSS requires a clear view of the sky to function properly. Indoor operation is possible near windows but will be degraded.

Q: What type of antenna should I use?

A: Use a GPS/GNSS antenna designed for L1 band. Active antennas with built-in amplifiers typically provide better performance, especially in challenging signal environments.

Q: How long does it take to get a GPS fix?

A: Cold start: 24 seconds. Hot start (with backup battery): 2 seconds.

Q: Can I use multiple GNSS constellations simultaneously?

A: Yes, the NEO-M9N can track up to four GNSS constellations simultaneously (GPS, GLONASS, Galileo, BeiDou), which improves accuracy and reduces time-to-fix.