GNSS GPS Integration

Overview

Use this skill to connect a GNSS/GPS module to an MCU over UART and turn raw output into a trusted fix. The hard parts are proving the byte stream is intact (NMEA XOR checksum, UBX sync), rejecting invalid fixes, and getting acceptable TTFF given antenna, sky view, and backup-power constraints.

When To Use

Use this skill when:

• The user integrates u-blox NEO-M8N, NEO-M9N, MAX-M10, or Quectel L76/L80/LC76 over UART.
• The work involves parsing $GxGGA, $GxRMC, $GxGSA, $GxGSV, the *hh XOR checksum, or the UBX binary protocol (0xB5 0x62, UBX-NAV-PVT).
• Symptoms include no satellites, TTFF too long, RMC status V, lat/lon of 0, truncated NMEA frames, or PPS not toggling.
• Configuration uses the legacy UBX-CFG-PRT/UBX-CFG-MSG messages (M8-era), the config-key interface UBX-CFG-VALSET/UBX-CFG-VALGET (M9/M10), or PMTK sentences (PMTK251, PMTK220, PMTK314).

Do not use this skill when the UART link itself is unproven; confirm bytes arrive at the correct baud first.

First Questions