Product Overview
The SparkFun Triband GNSS RTK Breakout uses the UM980 module from Unicore Communications to deliver positioning data with exceptional accuracy. How accurate? When an RTK solution is reached, this board knows its X, Y, and Z location within roughly the width of a fingernail (~8mm horizontal and 15mm vertical). Whether you are building autonomous agricultural robots, surveying drones, or high-precision 5G timing networks, this breakout provides the centimeter-level data you need.
The Tri-Band Advantage
Based on the advanced Nebulas IV™ chip, the UM980 is a 1408-channel device that simultaneously tracks all major global navigation systems—GPS, GLONASS, Galileo, Beidou, QZSS, and SBAS—across three frequency bands (L1, L2, and L5/E6).
- Why Tri-Band? Tracking the L5 band enables the module to mitigate better multipath interference (signals bouncing off buildings or trees), ensuring a faster, more stable fix in challenging environments where dual-band receivers may struggle.

Rover & Base Station Capable
The UM980 is a versatile powerhouse capable of operating as either a Rover or a Base Station:
- Rover: Receives correction data to calculate its precise location.
- Base Station: Uses "Survey-in" mode to determine its fixed position and broadcast RTCM 3.x correction data to other devices.
- Backup Battery: Includes a rechargeable backup battery to maintain satellite data and module configuration, drastically reducing time-to-first-fix (~24s cold start vs. instantaneous hot start).
Connectivity Options
To ensure a secure connection to your external antenna, we have included a robust SMA connector. For data communication, the UM980 relies exclusively on Serial UART (I2C is not supported on this module). We have made accessing these serial ports easy via three distinct methods:
| USB-C | Connected via an onboard CH340 for plug-and-play evaluation with a PC. |
| Locking JST | A 4-pin locking JST connector for secure wire-to-board integration. |
| BlueSMiRF Header | A dedicated header designed to mate with SparkFun Bluetooth modems for wireless data transmission. |
