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v1.13.15 - GET_TIME Command and GNSS Handler Enhancements (2025-12-11)

What Changed?

This release adds comprehensive time synchronization diagnostics with the new GET_TIME command, which simultaneously retrieves device uptime, RTC time, GNSS-synchronized time, and their difference. Additionally, the GNSS command handler suite has been significantly expanded to provide individual query commands for all position and status fields, complementing the master GET_GNSS command. All enhancements maintain full backward compatibility.

What's New

Main Feature: GET_TIME Command - Time Synchronization Diagnostics

What it does: The GET_TIME command retrieves four time-related values in a single response: device uptime (milliseconds since boot), RTC time (device real-time clock unix timestamp), GNSS time (GPS-synchronized unix timestamp), and the difference between RTC and GNSS times. This enables real-time verification of time source synchronization and tracking of clock drift between the two time sources.

How to use it: Send the GET_TIME command via serial interface. The response includes all four fields as a JSON object.

Code example:

# Via serial terminal
GET_TIME

# Response
{"type":"response","status":"ok","sent_at":12345,"uptime_ms":123456789,"rtc_time":1732046789,"gnss_time":1732046795,"time_diff":6}

Secondary Feature: Expanded GNSS Command Suite

What it does:

Complements the existing master GET_GNSS command with nine individual query commands for specific GNSS fields:

  • GET_GNSS_LATITUDE - Geographic latitude (-90 to 90 degrees)
  • GET_GNSS_LONGITUDE - Geographic longitude (-180 to 180 degrees)
  • GET_GNSS_ALTITUDE - Altitude above sea level (meters)
  • GET_GNSS_POSITION - Combined position data (latitude, longitude, altitude)
  • GET_GNSS_TIME - GNSS-synchronized unix timestamp
  • GET_GNSS_SATELLITES - Number of visible satellites
  • GET_GNSS_QUALITY - Fix quality indicator (0=invalid, 1=GPS, 2=DGPS, etc.)
  • GET_GNSS_VALID - Fix validity status (true/false)
  • GET_GNSS_HDOP - Horizontal Dilution of Precision (accuracy measure)

How to use it: Query individual GNSS fields as needed. For comprehensive data retrieval, use GET_GNSS or GET_GNSS_POSITION.

Code example:

# Query latitude only
GET_GNSS_LATITUDE

# Response
{"type":"response","status":"ok","sent_at":12345,"latitude":35.6762}

Installation

Quick Start

# Get the release
git checkout v1.13.15

# Build
task build

# Upload
task upload

# Check it works
task monitor

What's Different from the Last Version?

✅ Added

  • GET_TIME command for comprehensive time synchronization diagnostics (uptime_ms, rtc_time, gnss_time, time_diff)
  • GET_GNSS master command for retrieving all GNSS data in single response
  • GET_GNSS_POSITION command for combined geographic position queries
  • Individual GNSS query commands: GET_GNSS_LATITUDE, GET_GNSS_LONGITUDE, GET_GNSS_ALTITUDE, GET_GNSS_TIME, GET_GNSS_SATELLITES, GET_GNSS_QUALITY, GET_GNSS_VALID, GET_GNSS_HDOP
  • Forward declarations and dispatch table entries for all 10 GNSS handlers

🔧 Changed

  • Updated command_manager.cpp dispatch table to include all 10 GNSS commands (previously 4)
  • All GNSS handlers now follow Phase 6 Payload Pointer Pattern (static JsonDocument with pointer-based responses)

🐛 Fixed

  • Removed undefined handler references (handle_sync_time, handle_get_gnss_status) from command dispatcher

Is It Safe to Upgrade?

Backward Compatible: Yes

  • All new GET_TIME and GET_GNSS commands are additive; no existing commands were modified
  • Existing users unaware of these commands will not be affected
  • No breaking changes to serial protocol or response formats
  • All changes only activate when ENABLE_GNSS=1 is set (optional feature)

Tests Passed

  • ✅ Builds without errors (verified with task build)
  • ✅ All GNSS handlers forward declarations properly resolved
  • ✅ Command dispatch table correctly maps 10 GNSS commands
  • ✅ GET_TIME command returns all four required fields (uptime_ms, rtc_time, gnss_time, time_diff)

Release Details

  • Date: 2025-12-11
  • Version: v1.13.15
  • Files Changed: 3（src/command/time.cpp (new)、src/command_manager.cpp、src/command/gnss.cpp）

Next Steps

  • Phase 6 Completion: Continue Phase 6 Payload Pointer Pattern migration for remaining command handlers（WiFi, configuration commands）
  • CommandParser Class: Implement unified command argument parsing framework to consolidate validation logic scattered across text_command_manager
  • GNSS Integration: Expand GNSS module with real-time satellite tracking and atmospheric correction capabilities
  • Performance Optimization: Profile command response latency under high-frequency queries