commit 572c43dab62f9e207781b96e7e48b7b38ca024e5
author James Feist <james.feist@linux.intel.com> Thu Jan 31 15:52:22 2019 -0800
committer James Feist <james.feist@linux.intel.com> Tue Feb 05 11:30:05 2019 -0800
tree 137db460c1d23e7a620a78b8a8cf8dd86891eeb8
parent 1738e2a2b705f64e0c823b095b504dfe397a87ab

Add Hysteresis to pid controllers

Add hysteresis to pid controllers to lower pwm changes.
It is defaulted to 0 so it should be transparent
to any controller that choses not to implement it.
This is the same pattern used by the stepwise controller.

Tested-by: Unit tests passed

Change-Id: Ib47114285b0017258b7f77eaf067d310f95a0c60
Signed-off-by: James Feist <james.feist@linux.intel.com>

pid/pidcontroller.hpp

diff --git a/pid/pidcontroller.hpp b/pid/pidcontroller.hpp
index 9ed3be2..3d38c2a 100644
--- a/pid/pidcontroller.hpp
+++ b/pid/pidcontroller.hpp
@@ -49,6 +49,11 @@
         return &_pid_info;
     }
 
+    double getLastInput(void)
+    {
+        return lastInput;
+    }
+
   protected:
     ZoneInterface* _owner;
 
@@ -57,4 +62,5 @@
     ec::pid_info_t _pid_info;
     double _setpoint;
     std::string _id;
+    double lastInput = std::numeric_limits<double>::quiet_NaN();
 };