From 3688e29cfe6586ea8427a5fdff624b1843f04ae7 Mon Sep 17 00:00:00 2001
From: 3djc <5167938+3djc@users.noreply.github.com>
Date: Tue, 5 May 2026 05:07:13 +0200
Subject: [PATCH] feat: support for ELRS/CRSF 0x03 GPS time frame (#7317)

---
 radio/src/telemetry/crossfire.cpp | 28 ++++++++++++++++++++++++++++
 radio/src/telemetry/crossfire.h   |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/radio/src/telemetry/crossfire.cpp b/radio/src/telemetry/crossfire.cpp
index 6314b9c76..5b7508a59 100644
--- a/radio/src/telemetry/crossfire.cpp
+++ b/radio/src/telemetry/crossfire.cpp
@@ -66,6 +66,7 @@ const CrossfireSensor crossfireSensors[] = {
   CS(GPS_ID,         3, STR_DEF(STR_SENSOR_HDG),           UNIT_DEGREE,            2),
   CS(GPS_ID,         4, STR_DEF(STR_SENSOR_GPSALT),        UNIT_METERS,            0),
   CS(GPS_ID,         5, STR_DEF(STR_SENSOR_SATELLITES),    UNIT_RAW,               0),
+  CS(GPS_TIME_ID,    0, STR_DEF(STR_SENSOR_GPSDATETIME),   UNIT_DATETIME,          0),
   CS(ATTITUDE_ID,    0, STR_DEF(STR_SENSOR_PITCH),         UNIT_RADIANS,           3),
   CS(ATTITUDE_ID,    1, STR_DEF(STR_SENSOR_ROLL),          UNIT_RADIANS,           3),
   CS(ATTITUDE_ID,    2, STR_DEF(STR_SENSOR_YAW),           UNIT_RADIANS,           3),
@@ -95,6 +96,8 @@ const CrossfireSensor & getCrossfireSensor(uint8_t id, uint8_t subId)
     return crossfireSensors[BATT_VOLTAGE_INDEX + subId];
   else if (id == GPS_ID)
     return crossfireSensors[GPS_LATITUDE_INDEX + subId];
+  else if (id == GPS_TIME_ID)
+    return crossfireSensors[GPS_TIME_INDEX];
   else if (id == CF_VARIO_ID)
     return crossfireSensors[VERTICAL_SPEED_INDEX];
   else if (id == ATTITUDE_ID)
@@ -176,6 +179,31 @@ void processCrossfireTelemetryFrame(uint8_t module, uint8_t* rxBuffer,
         processCrossfireTelemetryValue(GPS_SATELLITES_INDEX, value);
       break;
 
+    case GPS_TIME_ID:
+    {
+      // Payload: year (2B BE), month, day, hour, min, sec, millisecond (2B BE)
+      const CrossfireSensor & sensor = crossfireSensors[GPS_TIME_INDEX];
+      if (!getCrossfireTelemetryValue<2>(3, value, rxBuffer))
+        break;
+      uint8_t year = (uint8_t)((uint16_t)value - 2000);
+      uint8_t month  = rxBuffer[5];
+      uint8_t day    = rxBuffer[6];
+      uint8_t hour   = rxBuffer[7];
+      uint8_t minute = rxBuffer[8];
+      uint8_t sec    = rxBuffer[9];
+      // Date record: low byte non-zero (acts as date/time discriminator)
+      uint32_t dateVal = ((uint32_t)year << 24) | ((uint32_t)month << 16)
+                       | ((uint32_t)day << 8) | 0xFF;
+      setTelemetryValue(PROTOCOL_TELEMETRY_CROSSFIRE, sensor.id, 0, sensor.subId,
+                        (int32_t)dateVal, UNIT_DATETIME, 0);
+      // Time record: low byte zero
+      uint32_t timeVal = ((uint32_t)hour << 24) | ((uint32_t)minute << 16)
+                       | ((uint32_t)sec << 8);
+      setTelemetryValue(PROTOCOL_TELEMETRY_CROSSFIRE, sensor.id, 0, sensor.subId,
+                        (int32_t)timeVal, UNIT_DATETIME, 0);
+      break;
+    }
+
     case BARO_ALT_ID:
       if (getCrossfireTelemetryValue<2>(3, value, rxBuffer)) {
         if (value & 0x8000) {
diff --git a/radio/src/telemetry/crossfire.h b/radio/src/telemetry/crossfire.h
index 3653d8e83..bdfc49561 100644
--- a/radio/src/telemetry/crossfire.h
+++ b/radio/src/telemetry/crossfire.h
@@ -32,6 +32,7 @@
 
 // Frame id
 #define GPS_ID                         0x02
+#define GPS_TIME_ID                    0x03
 #define CF_VARIO_ID                    0x07
 #define BATTERY_ID                     0x08
 #define BARO_ALT_ID                    0x09
@@ -85,6 +86,7 @@ enum CrossfireSensorIndexes {
   GPS_HEADING_INDEX,
   GPS_ALTITUDE_INDEX,
   GPS_SATELLITES_INDEX,
+  GPS_TIME_INDEX,
   ATTITUDE_PITCH_INDEX,
   ATTITUDE_ROLL_INDEX,
   ATTITUDE_YAW_INDEX,