From 1b7fb27404ebd74c06e4acd3e8a63526df28b549 Mon Sep 17 00:00:00 2001
From: Michael <101.37584@germanynet.de>
Date: Thu, 15 Jan 2026 18:44:35 +0100
Subject: [PATCH 1/4] initial commit

---
 radio/src/pulses/crossfire.cpp | 48 +++++++++++++++++++++++-----------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/radio/src/pulses/crossfire.cpp b/radio/src/pulses/crossfire.cpp
index 18fc7f61269..be0dc25077b 100644
--- a/radio/src/pulses/crossfire.cpp
+++ b/radio/src/pulses/crossfire.cpp
@@ -96,20 +96,20 @@ uint8_t createCrossfireModelIDFrame(uint8_t moduleIdx, uint8_t * frame)
 uint8_t createCrossfireChannelsFrame(uint8_t moduleIdx, uint8_t * frame, int16_t * pulses)
 {
   //
-  // sends channel data and also communicates commanded armed status in arming mode Switch.
-  // frame len 24 -> arming mode CH5: module will use channel 5
-  // frame len 25 -> arming mode Switch: send commanded armed status in extra byte after channel data
-  // 
-  ModuleData *md = &g_model.moduleData[moduleIdx];
-
-  uint8_t armingMode = md->crsf.crsfArmingMode; // 0 = Channel mode, 1 = Switch mode
-  uint8_t lenAdjust = (armingMode == ARMING_MODE_SWITCH) ? 1 : 0;
-
+  // sends channel data and also communicates status information in status byte:
+  // - arming mode Switch or CH5
+  // - arming status in Switch mode
+  // - crsf errors
+  //
   uint8_t * buf = frame;
   *buf++ = MODULE_ADDRESS;
-  *buf++ = 24 + lenAdjust;      // 1(ID) + 22(channel data) + (+1 extra byte if Switch mode) + 1(CRC)
+  *buf++ = 25;                  // 1(ID) + 22(channel data) + 1(extra status byte) + 1(CRC)
   uint8_t * crc_start = buf;
   *buf++ = CHANNELS_ID;
+
+  //
+  // assemble channel data
+  //
   uint32_t bits = 0;
   uint8_t bitsavailable = 0;
   for (int i=0; i<CROSSFIRE_CHANNELS_COUNT; i++) {
@@ -122,14 +122,33 @@ uint8_t createCrossfireChannelsFrame(uint8_t moduleIdx, uint8_t * frame, int16_t
       bitsavailable -= 8;
     }
   }
-  
-  if (armingMode == ARMING_MODE_SWITCH) {
+
+  //
+  // assemble status byte
+  //
+  ModuleData *md = &g_model.moduleData[moduleIdx];
+
+  if (md->crsf.crsfArmingMode == ARMING_MODE_SWITCH) {
     swsrc_t sw =  md->crsf.crsfArmingTrigger;
 
-    *buf++ = (sw != SWSRC_NONE) && getSwitch(sw, 0);  // commanded armed status in Switch mode
+    *buf = (sw != SWSRC_NONE) && getSwitch(sw, 0);  // commanded armed status in Switch mode
+  } else {
+    *buf = 0x02;                                    // flag arming mode CH5
+  }
+
+  extern bool crsfErrorFlag;
+  if(crsfErrorFlag) {
+    *buf |= 0x04;                                   // flag crsf error
+    crsfErrorFlag = false;
   }
+
+  buf++;
   
-  *buf++ = crc8(crc_start, 23 + lenAdjust);
+  //
+  // add crc
+  //
+  *buf++ = crc8(crc_start, 24);
+
   return buf - frame;
 }
 
@@ -452,5 +471,4 @@ const etx_proto_driver_t CrossfireDriver = {
   .processData = nullptr,
   .processFrame = crossfireProcessFrame,
   .onConfigChange = nullptr,
-  .txCompleted = modulePortSerialTxCompleted,
 };

From a6406bc80e73374e49b7fb55f1e6b2d12cba655a Mon Sep 17 00:00:00 2001
From: Michael <101.37584@germanynet.de>
Date: Thu, 15 Jan 2026 18:53:24 +0100
Subject: [PATCH 2/4] make flagging crsf errors an example

---
 radio/src/pulses/crossfire.cpp | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/radio/src/pulses/crossfire.cpp b/radio/src/pulses/crossfire.cpp
index be0dc25077b..6015660ad7f 100644
--- a/radio/src/pulses/crossfire.cpp
+++ b/radio/src/pulses/crossfire.cpp
@@ -136,11 +136,13 @@ uint8_t createCrossfireChannelsFrame(uint8_t moduleIdx, uint8_t * frame, int16_t
     *buf = 0x02;                                    // flag arming mode CH5
   }
 
-  extern bool crsfErrorFlag;
-  if(crsfErrorFlag) {
-    *buf |= 0x04;                                   // flag crsf error
-    crsfErrorFlag = false;
-  }
+  // Example: flag crsf errors to ELRS in bit 2 for resending linkstats
+  //
+  //extern bool crsfErrorFlag;
+  //if(crsfErrorFlag) {
+  //  *buf |= 0x04;                                   // flag crsf error
+  //  crsfErrorFlag = false;
+  //}
 
   buf++;
   

From de13f39c03b924aa961941f86edccad0e15b717b Mon Sep 17 00:00:00 2001
From: Michael <101.37584@germanynet.de>
Date: Thu, 15 Jan 2026 19:00:37 +0100
Subject: [PATCH 3/4] updated comment on bit meanings

---
 radio/src/pulses/crossfire.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/radio/src/pulses/crossfire.cpp b/radio/src/pulses/crossfire.cpp
index 6015660ad7f..cd49191db06 100644
--- a/radio/src/pulses/crossfire.cpp
+++ b/radio/src/pulses/crossfire.cpp
@@ -97,9 +97,9 @@ uint8_t createCrossfireChannelsFrame(uint8_t moduleIdx, uint8_t * frame, int16_t
 {
   //
   // sends channel data and also communicates status information in status byte:
-  // - arming mode Switch or CH5
-  // - arming status in Switch mode
-  // - crsf errors
+  // - arming status in Switch mode (bit 0)
+  // - arming mode Switch or CH5 (bit 1)
+  // - bits 2-7 spare
   //
   uint8_t * buf = frame;
   *buf++ = MODULE_ADDRESS;

From 2ca8d269a2130bb103318d751d5e5e55a9c9f1d1 Mon Sep 17 00:00:00 2001
From: Michael <101.37584@germanynet.de>
Date: Thu, 15 Jan 2026 20:30:29 +0100
Subject: [PATCH 4/4] fix merge error

---
 radio/src/pulses/crossfire.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/radio/src/pulses/crossfire.cpp b/radio/src/pulses/crossfire.cpp
index cd49191db06..a94aad449ba 100644
--- a/radio/src/pulses/crossfire.cpp
+++ b/radio/src/pulses/crossfire.cpp
@@ -473,4 +473,5 @@ const etx_proto_driver_t CrossfireDriver = {
   .processData = nullptr,
   .processFrame = crossfireProcessFrame,
   .onConfigChange = nullptr,
+  .txCompleted = modulePortSerialTxCompleted,
 };