Navisys GR-U01W USB PPS Timing GNSS — GPSD / NTP Ready (~0.5 ms)
Navisys GR-U01W USB PPS Timing GNSS — GPSD / NTP Ready (~0.5 ms)
Country of Origin: Taiwan
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| Minimum Qty | Discount |
|---|---|
| 5 + | 3% off |
| 10 + | 4% off |
| 50 + | 5% off |
| 100 + | 7% off |
The NaviSys GR-U01W is a Timing / NTP GNSS receiver built on u-blox’s M10 engine. It delivers a 1PPS timing reference over a standard USB connection—no dedicated PPS wire required—with host time-transfer precision typically around 0.5 ms.
Use it when you need a simple USB GNSS mouse for clock synchronization (NTP / GPSD) as well as multi-constellation L1 positioning. It is the current Macx-1 “W” model and the recommended successor to the well-known GR-601W, GR-701W, and GR-801W (also known as GR-8013W).
Like the rest of the GR-U01 family, the GR-U01W is compact (40 × 45 × 16 mm), IP67 waterproof, fully EMI shielded, and rated for industrial temperatures from −40°C to +85°C.
PPS over USB · typically 0.5 ms host precision · GPSD / NTP ready · u-blox M10 · 1.5 m accuracy · Up to 18 Hz · Concurrent GPS + GLONASS + Galileo + BeiDou · IP67 · 1.5 m USB cable
PPS over USB — Built for Timing
Most USB GNSS receivers output NMEA position only. The GR-U01W also exposes a 1PPS (one pulse per second) timing reference through the USB interface itself.
- PPS events appear as DCD state transitions to the host’s PL2303 USB-serial driver
- No separate PPS cable or GPIO wiring
- Compatible with open-source GPSD PPS support for Linux / BSD timing stacks
- Host time-transfer precision is bounded by the USB polling interval—typically 0.5 ms (W-series about 0.5–1 ms)
→ Plug into USB, feed GPSD / NTP, and use GNSS-disciplined time without a dedicated PPS line
Where It Fits
NTP / Stratum-1 Style Time Sources
- Low-cost USB GNSS reference for NTP
- Works with GPSD as a time source on Linux and BSD
- Useful for servers, routers, and lab clocks that need GNSS lock
→ USB-simple timing when microsecond-class serial PPS is not required
Timing-Critical Applications
- Precise clocks and synchronized devices
- Network / traffic timing and delay analysis
- Multi-device time alignment over a shared GNSS reference
→ One USB mouse for both position and a 1PPS time tick
W-Series Background
The Navisys “W” models were created so that 1PPS could travel over a normal USB cable. The first unit, GR-601W, was developed with input from Eric S. Raymond and the Bufferbloat community and earned the nickname Macx-1. It became a familiar choice in GPSD / NTP discussions for USB-based timing.
The line then moved through GR-701W and GR-801W (also known as GR-8013W) as the GNSS chipsets advanced. The GR-U01W is the current generation: same Macx-1 USB-PPS idea, now on u-blox M10 with concurrent four-constellation L1 tracking.
For new Timing / NTP deployments, GR-U01W is the model to choose. The older W receivers remain historically important; GR-U01W is the modern replacement.
→ Same USB-PPS Macx-1 concept hobbyists and timing users already know—updated to M10
Key Features
1PPS over USB
- 1PPS timing reference on the USB cable
- Presented as DCD events to the PL2303 driver
- Typically 0.5 ms host precision (about 0.5–1 ms for W-series)
- GPSD PPS compatible
→ The defining difference versus GR-U01U (navigation USB without PPS-over-USB)
u-blox M10 · Multi-Constellation
- Concurrent GPS, GLONASS, Galileo, BeiDou (L1)
- QZSS + SBAS (WAAS, EGNOS, MSAS, GAGAN)
- Default 1 Hz; up to 18 Hz (GPS only)
- 1.5 m horizontal (GPS + QZSS + SBAS)
→ Modern L1 engine for both timing lock and navigation
Interference & Spoofing Awareness
- Anti-jamming support
- RF interference detection
- Spoofing detection and reporting
→ Extra resilience when the RF environment is noisy or hostile
Industrial USB Form Factor
- 40 (W) × 45 (L) × 16 (H) mm
- IP67 waterproof · built-in magnet
- Fully EMI shielded
- Operating temperature: −40°C to +85°C
- 1.5 m USB Type-A cable · 5 VDC USB powered
→ Outdoor-ready mouse receiver, not a bare module
u-blox U-Center 2 Tool
The GR-U01W uses the u-blox M10 chip and is fully compatible with the latest u-center 2 software for GNSS receiver configuration. u-blox provides user and developer documentation to support evaluation and development.
U-center 2 is designed for u-blox M10 and F10 products. It is free from the u-blox website, and a copy is also available in the Product Resources section of this page.
Navisys NaviViewerUx Tool
In addition to U-Center 2, Navisys provides NaviViewerUx for convenient configuration and diagnostics of the GR-U01W GNSS receiver.
Receiver Specifications
GNSS Receiver Type
- u-blox M10 engine
- GPS, SBAS: L1 C/A — 1575.42 MHz
- QZSS: L1 C/A/S — 1575.42 MHz
- Galileo: E1 B/C — 1575.42 MHz
- GLONASS: L1OF — 1598.0625~1605.375 MHz
- BeiDou: B1I — 1561.098 MHz; B1C — 1575.42 MHz
Accuracy & Timing
| Horizontal position | 1.5 m (GPS + QZSS + SBAS) CEP, 50%, 24 hr static, −130 dBm, 6+ SVs for each system |
| Velocity | <0.05 m/s (speed) · <0.3° (heading) · 50% @ 30 m/s |
| Time pulse (chip) | RMS: 30 ns · 99%: <60 ns |
| PPS over USB (host) |
Typically 0.5 ms via USB DCD / PL2303 Bounded by USB polling interval; W-series about 0.5–1 ms Output: 1PPS |
TTFF (Time to First Fix)
| Hot start | 1 s |
| Cold start | 28 s: GPS + GAL 23 s: GPS + GAL + GLO 27 s: GPS + GAL + BDS B1I (default) 28 s: GPS + GAL + BDS B1C 23 s: GPS + GAL + GLO + BDS B1C |
Sensitivity (Autonomous)
| Acquisition | −148 dBm (GPS & Galileo or more) |
| Tracking | −167 dBm (GPS & Galileo or more) |
Measurement Data Output
- Interface: USB Type-A (PL2303); NMEA / UBX over virtual serial
- UART framing: N,8,1 · baud 4800, 9600, 19200, 38400 (default), 57600, 115200, 230400, 460800, 921600
- NMEA versions 2.1, 2.3, 4.0, 4.10, and 4.11 (default)
- UBX (u-blox proprietary)
- Sentences: GGA, GLL, GSA, GSV, RMC, VTG, TXT
- Datum: WGS-84
Navigation Update Rate
| Default | 1 Hz |
| GPS + GAL + GLO + BDS B1C | 5 Hz |
| GPS + GAL + BDS B1C | 8 Hz |
| GPS + GAL + BDS B1I | 5 Hz |
| GPS + GAL + GLO | 7 Hz |
| GPS + GAL | 10 Hz |
| GPS only | 18 Hz |
Dynamics & Limits
| Max. altitude | < 80,000 m |
| Max. velocity | < 500 m/s |
| Dynamics | < 4 g |
| Augmentation | SBAS: WAAS, EGNOS, MSAS, GAGAN · QZSS (L1S SLAS) |
Power
| Power consumption | (29 GNSS SVs fixed for tracking) USB: 59 / 56 mA (acquisition / tracking) |
| Power supply | 5 VDC (USB) |
| Backup power | 3.3 V (backup battery for faster fix) |
Mechanical & Environment
| Dimension | 40 (W) × 45 (L) × 16 (H) mm |
| Weight | 68.8 g (with 1.5 m cable and USB-A) |
| Cable / connector | 1.5 m USB Type-A (GR-U01W) |
| Waterproof | IP67 · built-in magnet · fully EMI shielded |
| Operating temperature | −40°C to +85°C (−20~60°C for backup battery) |
| Storage temperature | −40°C to +85°C (−40~60°C for backup battery) |
What's in the Box
- Navisys GR-U01W Timing / NTP GNSS Receiver × 1
Product Resources
Official Documents
Downloads
For Windows 10, Windows 11, Android, and Linux, native drivers are already included with the operating system. There’s no need to download or install additional drivers. Simply plug in the GNSS receiver, and it will be recognized and start working immediately.
USB Drivers
- Windows Drivers
- WinCE for x86
- WinCE for ARM/xScale
- macOS driver
- Linux Driver for Linux Kernel V2.6.15 to V5.4
- USB GNSS driver already built into Linux OS 5.5 and above — no download needed
Tools
How-to Articles and Blogs
Tech Support Topics and Forums
