From e1a8a80584008ae0803991e3042c18ae271b954c Mon Sep 17 00:00:00 2001
From: ctzsnooze <chris.thompson@sydney.edu.au>
Date: Tue, 10 Sep 2019 19:08:20 +1000
Subject: [PATCH] fixes for ff_boost

1.  Excludes yaw from ff_boost.
2.  Removes suppression for 3x greater up-steps in FF to reduce boost glitching around zero sticks
3.  Spike detection gets cleaner passband and tighter rejection above threshold; higher threshold is now possible with better suppression of large spikes.
---
 src/main/flight/interpolated_setpoint.c | 19 ++++++++++---------
 src/main/flight/pid.c                   |  2 +-
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/main/flight/interpolated_setpoint.c b/src/main/flight/interpolated_setpoint.c
index fbe1000a4..0d54e8780 100644
--- a/src/main/flight/interpolated_setpoint.c
+++ b/src/main/flight/interpolated_setpoint.c
@@ -66,15 +66,16 @@ FAST_CODE_NOINLINE float interpolatedSpApply(int axis, bool newRcFrame, ffInterp
         const float ffBoostFactor = pidGetFfBoostFactor();
         float clip = 1.0f;
         float boostAmount = 0.0f;
-        if (ffBoostFactor != 0.0f) {
-            if (pidGetSpikeLimitInverse()) {
-                clip = 1 / (1 + fabsf(setpointAcceleration * pidGetSpikeLimitInverse()));
-                clip *= clip;
-            }
-
-            // prevent kick-back spike at max deflection
-            if (fabsf(rawSetpoint) < 0.95f * ffMaxRate[axis] || fabsf(setpointSpeed) > 3.0f * fabsf(prevSetpointSpeed[axis])) {
-                boostAmount = ffBoostFactor * setpointAcceleration;
+        if ((axis == FD_ROLL)||(axis == FD_PITCH)) {
+            if (ffBoostFactor != 0.0f) {
+                if (pidGetSpikeLimitInverse()) {
+                    clip = 1 / (1 + (setpointAcceleration * setpointAcceleration * pidGetSpikeLimitInverse()));
+                    clip *= clip;
+                }
+                // prevent kick-back spike at max deflection
+                if (fabsf(rawSetpoint) < 0.95f * ffMaxRate[axis]) {
+                   boostAmount = ffBoostFactor * setpointAcceleration;
+                }
             }
         }
         prevSetpointSpeed[axis] = setpointSpeed;
diff --git a/src/main/flight/pid.c b/src/main/flight/pid.c
index efdd04d7c..73c3c31d2 100644
--- a/src/main/flight/pid.c
+++ b/src/main/flight/pid.c
@@ -213,7 +213,7 @@ void resetPidProfile(pidProfile_t *pidProfile)
         .idle_pid_limit = 200,
         .idle_max_increase = 150,
         .ff_interpolate_sp = FF_INTERPOLATE_AVG,
-        .ff_spike_limit = 40,
+        .ff_spike_limit = 60,
         .ff_max_rate_limit = 100,
         .ff_boost = 15,
     );
-- 
2.11.4.GIT