From 9e73922fd96295850cc7466b3b8ca9fd0209c5f0 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Sun, 8 Nov 2020 21:57:10 +1100
Subject: [PATCH] AC_PID: use calc_lowpass_alpha_dt()

---
 libraries/AC_PID/AC_PID.cpp | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/libraries/AC_PID/AC_PID.cpp b/libraries/AC_PID/AC_PID.cpp
index 1805c12bd3..fe8c596d48 100644
--- a/libraries/AC_PID/AC_PID.cpp
+++ b/libraries/AC_PID/AC_PID.cpp
@@ -325,13 +325,7 @@ float AC_PID::get_filt_D_alpha() const
 // get_filt_alpha - calculate a filter alpha
 float AC_PID::get_filt_alpha(float filt_hz) const
 {
-    if (is_zero(filt_hz)) {
-        return 1.0f;
-    }
-
-    // calculate alpha
-    float rc = 1 / (M_2PI * filt_hz);
-    return _dt / (_dt + rc);
+    return calc_lowpass_alpha_dt(_dt, filt_hz);
 }
 
 void AC_PID::set_integrator(float target, float measurement, float i)