From 0b7f591671ad9d03ff28e8e1b93f300b35c745dc Mon Sep 17 00:00:00 2001
From: Matthew Kennedy <matthewkennedy@outlook.com>
Date: Sat, 31 Oct 2020 17:34:36 -0700
Subject: [PATCH] heater PID works

---
 firmware/heater_control.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/firmware/heater_control.cpp b/firmware/heater_control.cpp
index 85eabb6..e8e07de 100644
--- a/firmware/heater_control.cpp
+++ b/firmware/heater_control.cpp
@@ -50,7 +50,7 @@ static HeaterState GetNextState(HeaterState state, float sensorEsr)
     return state;
 }
 
-static Pid heaterPid(0.1f, 0, HEATER_CONTROL_PERIOD);
+static Pid heaterPid(0.1f, 0.1f, HEATER_CONTROL_PERIOD);
 
 static float GetDutyForState(HeaterState state, float heaterEsr)
 {
@@ -66,7 +66,8 @@ static float GetDutyForState(HeaterState state, float heaterEsr)
 
             return rampDuty;
         case HeaterState::ClosedLoop:
-            return heaterPid.GetOutput(HEATER_TARGET_ESR, heaterEsr);
+            // Negated because lower resistance -> hotter
+            return heaterPid.GetOutput(-HEATER_TARGET_ESR, -heaterEsr);
     }
 }