From 414a9993b3e96700118a14f6eea3bc526cb57224 Mon Sep 17 00:00:00 2001
From: Jye <14170229+JyeSmith@users.noreply.github.com>
Date: Sat, 28 Dec 2024 09:09:50 +1000
Subject: [PATCH] Communicate Rx available antenna mode to the Tx (#3039)

* add-tlmConfirm-to-tlm_dl-ota-packet-structure

* clean up naming

* Auto set True Diversity Rx into Diversity or Gemini mode based on Tx antenna mode

* Auto configure Rx OTA protocol from the Tx

* replace second packet memcmp with crc

LR1121 working

* remove unnecessary GPIO_PIN_NSS_2  check

* update SX1280 driver and also remove isFirstRxIrq

* update sx1276 driver and remove isFirstRxIrq

* update tx_main

* cleanup

* update after master merge

* cleanup

* update LR1121

* remove comment

* down link data

* do not switch when in GemX mode

* correct tlm_dl pkt buffer

* POC fix optimising the mavlink SS payload size

This reduces the number of partially filled pkts OTA via the SS.

This need to be done correctly and in a generic way!!!

* optimise mavlink SS packet size

* correct txnb for rx diversity mode

* update sx1280 and sx1276 drivers

* Communite Rx available antenna mode to the Tx
---
 src/lib/OTA/OTA.h   |  7 +++++--
 src/src/rx_main.cpp |  5 ++++-
 src/src/tx_main.cpp | 12 ++++++++++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/lib/OTA/OTA.h b/src/lib/OTA/OTA.h
index 45425751..dba80f51 100644
--- a/src/lib/OTA/OTA.h
+++ b/src/lib/OTA/OTA.h
@@ -88,7 +88,8 @@ typedef struct {
             union {
                 struct {
                     OTA_LinkStats_s stats;
-                    uint8_t free;
+                    uint8_t trueDiversityAvailable:1,
+                            free:7;
                 } PACKED ul_link_stats;
                 uint8_t payload[ELRS4_TELEMETRY_BYTES_PER_CALL];
             };
@@ -144,7 +145,9 @@ typedef struct {
             union {
                 struct {
                     OTA_LinkStats_s stats;
-                    uint8_t payload[ELRS8_TELEMETRY_BYTES_PER_CALL - sizeof(OTA_LinkStats_s)];
+                    uint8_t trueDiversityAvailable:1,
+                            free:7;
+                    uint8_t payload[ELRS8_TELEMETRY_BYTES_PER_CALL - sizeof(OTA_LinkStats_s) - 1];
                 } PACKED ul_link_stats;
                 uint8_t payload[ELRS8_TELEMETRY_BYTES_PER_CALL]; // containsLinkStats == false
             };
diff --git a/src/src/rx_main.cpp b/src/src/rx_main.cpp
index 1d8cc597..8d3f7650 100644
--- a/src/src/rx_main.cpp
+++ b/src/src/rx_main.cpp
@@ -471,12 +471,14 @@ bool ICACHE_RAM_ATTR HandleSendTelemetryResponse()
         otaPkt.std.type = PACKET_TYPE_LINKSTATS;
 
         OTA_LinkStats_s * ls;
-        ls = &otaPkt.full.tlm_dl.ul_link_stats.stats;
 
         // Include some advanced telemetry in the extra space
         // Note the use of `ul_link_stats.payload` vs just `payload`
         if (OtaIsFullRes)
         {
+            ls = &otaPkt.full.tlm_dl.ul_link_stats.stats;
+            otaPkt.full.tlm_dl.ul_link_stats.trueDiversityAvailable = isDualRadio();
+
             otaPkt.full.tlm_dl.tlmConfirm = MspReceiver.GetCurrentConfirm() ? 1 : 0;
 
             if (geminiMode)
@@ -502,6 +504,7 @@ bool ICACHE_RAM_ATTR HandleSendTelemetryResponse()
         else
         {
             ls = &otaPkt.std.tlm_dl.ul_link_stats.stats;
+            otaPkt.std.tlm_dl.ul_link_stats.trueDiversityAvailable = isDualRadio();
             LinkStatsToOta(ls);
         }
 
diff --git a/src/src/tx_main.cpp b/src/src/tx_main.cpp
index cc1fdd6a..46d7fc0a 100644
--- a/src/src/tx_main.cpp
+++ b/src/src/tx_main.cpp
@@ -205,6 +205,12 @@ bool ICACHE_RAM_ATTR ProcessTLMpacket(SX12xxDriverCommon::rx_status const status
       case PACKET_TYPE_LINKSTATS:
         LinkStatsFromOta(&ota8->tlm_dl.ul_link_stats.stats);
 
+        // The Rx only has a single radio.  Force the Tx out of Gemini mode. 
+        if (config.GetAntennaMode() == TX_RADIO_MODE_GEMINI && !ota8->tlm_dl.ul_link_stats.trueDiversityAvailable)
+        {
+            config.SetAntennaMode(TX_RADIO_MODE_SWITCH);
+        }    
+
         if (config.GetAntennaMode() == TX_RADIO_MODE_GEMINI)
         {
             if (Radio.GetProcessingPacketRadio() == SX12XX_Radio_1)
@@ -301,6 +307,12 @@ bool ICACHE_RAM_ATTR ProcessTLMpacket(SX12xxDriverCommon::rx_status const status
     {
       case PACKET_TYPE_LINKSTATS:
         LinkStatsFromOta(&otaPktPtr->std.tlm_dl.ul_link_stats.stats);
+
+        // The Rx only has a single radio.  Force the Tx out of Gemini mode. 
+        if (config.GetAntennaMode() == TX_RADIO_MODE_GEMINI && !otaPktPtr->std.tlm_dl.ul_link_stats.trueDiversityAvailable)
+        {
+            config.SetAntennaMode(TX_RADIO_MODE_SWITCH);
+        }
         break;
 
       case PACKET_TYPE_DATA:
-- 
2.11.4.GIT