From 5def9e70388e58188668c03998c70ec08db01ae8 Mon Sep 17 00:00:00 2001
From: Iampete1 <iampete@hotmail.co.uk>
Date: Tue, 12 Sep 2023 20:40:07 +0100
Subject: [PATCH] AP_Logger: PID move limit to flag bit

---
 libraries/AP_Logger/LogFile.cpp    | 11 ++++++++++-
 libraries/AP_Logger/LogStructure.h |  7 ++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/libraries/AP_Logger/LogFile.cpp b/libraries/AP_Logger/LogFile.cpp
index 5058d78bf0..b5230db774 100644
--- a/libraries/AP_Logger/LogFile.cpp
+++ b/libraries/AP_Logger/LogFile.cpp
@@ -473,6 +473,15 @@ void AP_Logger::Write_ServoStatus(uint64_t time_us, uint8_t id, float position,
 // Write a Yaw PID packet
 void AP_Logger::Write_PID(uint8_t msg_type, const AP_PIDInfo &info)
 {
+    enum class log_PID_Flags : uint8_t {
+        LIMIT = 1U<<0, // true if the output is saturated, I term anti windup is active
+    };
+
+    uint8_t flags = 0;
+    if (info.limit) {
+        flags |= (uint8_t)log_PID_Flags::LIMIT;
+    }
+
     const struct log_PID pkt{
         LOG_PACKET_HEADER_INIT(msg_type),
         time_us         : AP_HAL::micros64(),
@@ -485,7 +494,7 @@ void AP_Logger::Write_PID(uint8_t msg_type, const AP_PIDInfo &info)
         FF              : info.FF,
         Dmod            : info.Dmod,
         slew_rate       : info.slew_rate,
-        limit           : info.limit
+        flags           : flags
     };
     WriteBlock(&pkt, sizeof(pkt));
 }
diff --git a/libraries/AP_Logger/LogStructure.h b/libraries/AP_Logger/LogStructure.h
index 0c44d8d38d..f819e89838 100644
--- a/libraries/AP_Logger/LogStructure.h
+++ b/libraries/AP_Logger/LogStructure.h
@@ -407,7 +407,7 @@ struct PACKED log_PID {
     float   FF;
     float   Dmod;
     float   slew_rate;
-    uint8_t limit;
+    uint8_t flags;
 };
 
 struct PACKED log_WheelEncoder {
@@ -676,7 +676,7 @@ struct PACKED log_VER {
 // UNIT messages define units which can be referenced by FMTU messages
 // FMTU messages associate types (e.g. centimeters/second/second) to FMT message fields
 
-#define PID_LABELS "TimeUS,Tar,Act,Err,P,I,D,FF,Dmod,SRate,Limit"
+#define PID_LABELS "TimeUS,Tar,Act,Err,P,I,D,FF,Dmod,SRate,Flags"
 #define PID_FMT    "QfffffffffB"
 #define PID_UNITS  "s----------"
 #define PID_MULTS  "F----------"
@@ -909,7 +909,8 @@ struct PACKED log_VER {
 // @Field: FF: controller feed-forward portion of response
 // @Field: Dmod: scaler applied to D gain to reduce limit cycling
 // @Field: SRate: slew rate used in slew limiter
-// @Field: Limit: 1 if I term is limited due to output saturation
+// @Field: Flags: bitmask of PID state flags
+// @FieldBitmaskEnum: Flags: log_PID_Flags
 
 // @LoggerMessage: PM
 // @Description: autopilot system performance and general data dumping ground