OCP M.2 ZED-F9P GNSS Module

OCP M.2 ZED-F9P GNSS Module

A compact M.2 2242 GPS board fully compliant with the OCP M.2 Sync Module specification (v1.1). Built around the u-blox ZED-F9P-05B, this module is unique in the lineup — it combines precision timing with RTK (Real-Time Kinematic) positioning, letting you turn a TimeHAT into both a PTP Grandmaster and an RTK Base Station simultaneously.

The hardware design is fully open source: View on GitHub

What’s in the Box

• ZED-F9P-05B M.2 2242 GNSS board
• U.FL to SMA adapter cable
• M.2 mounting screw

Compatible Platforms

This module works in any design that supports OCP M.2 GPS receivers, including:

• TimeHAT (v6) — Raspberry Pi 5 PCIe HAT with I226 NIC and precision timing
• OCP Time Card — GitHub / Available from Makerfabs

About the ZED-F9P

The u-blox ZED-F9P-05B is a multi-band, high-precision GNSS receiver designed for both timing and positioning applications. Unlike the ZED-F9T (timing-only), the F9P adds centimeter-level RTK positioning on top of precise 1PPS output.

• Multi-constellation: GPS, GLONASS, Galileo, BeiDou
• Multi-band reception for improved accuracy and reliability
• High-accuracy 1PPS output for PTP grandmaster clock disciplining
• RTK support — centimeter-level positioning for base station applications
• UART interface — communicates via standard serial connection
• OCP M.2 Sync compliant — plug-and-play with supported platforms

What is RTK?

Real-Time Kinematic (RTK) positioning uses carrier-phase measurements from GNSS signals to achieve centimeter-level positioning accuracy — far beyond standard GPS. With the F9P as an RTK base station, you can provide correction data to nearby RTK rovers for high-precision positioning applications.

• u-blox: What is RTK?
• Wikipedia: Real-time kinematic positioning
• SparkFun: What is GPS RTK?

GNSS Module Comparison

• ZED-F9P (this module): Multi-band, PTP grandmaster + RTK base station — best for combined timing and positioning use cases
• ZED-F9T: Timing-grade, multi-band, nanosecond 1PPS — best for pure grandmaster clock applications
• Neo-M9N: Single-band, general-purpose GNSS — great for most PTP client and lab use cases at a lower cost

Using with TimeHAT — rtkbase Setup

For use with the TimeHAT, the recommended software is rtkbase.

Before running the install script, edit install.sh to add ttyAMA0 alongside ttyUSB0 (search for ttyUSB0 in the file and add ttyAMA0 to the list). Then run:

sudo ./install.sh --detect-gnss --configure-gnss

Note: rtkbase will also run gpsd, so you can use cgps for monitoring. It will configure the receiver for 115200 baud rate and save that setting — keep this in mind if you later uninstall rtkbase and return to manual gpsd configuration.

Open Source Hardware

The board design is fully open source under the Time Appliances Project. View schematics, layout files, and BOM on GitHub: Time-Appliances-Project / Time-Card / GNSS / M2-ZED-F9T