Optimize PID control at low increasing temps, decrease max steps to 2…

…5 to free memory
xjp13 · Jun 26, 2011 · 24effef · 24effef
1 parent 8a1aafc
commit 24effef
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/arduino/OpenPCR/thermocycler.cpp b/arduino/OpenPCR/thermocycler.cpp
@@ -78,6 +78,11 @@ PROGMEM const unsigned int LID_RESISTANCE_TABLE[] = {
 #define PLATE_PID_INC_I 250
 #define PLATE_PID_INC_D 250
 
+#define PLATE_PID_INC_LOW_THRESHOLD 40
+#define PLATE_PID_INC_LOW_P 2000
+#define PLATE_PID_INC_LOW_I 1000
+#define PLATE_PID_INC_LOW_D 800
+
 #define PLATE_PID_DEC_HIGH_THRESHOLD 70
 #define PLATE_PID_DEC_HIGH_P 800
 #define PLATE_PID_DEC_HIGH_I 700
@@ -418,7 +423,10 @@ void Thermocycler::SetPlateTarget(double target) {
   if (iRamping) {
     if (iTargetPlateTemp >= iPlateTemp) {
       iDecreasing = false;
-      iPlatePid.SetTunings(PLATE_PID_INC_P, PLATE_PID_INC_I, PLATE_PID_INC_D);
+      if (iTargetPlateTemp < PLATE_PID_INC_LOW_THRESHOLD)
+        iPlatePid.SetTunings(PLATE_PID_INC_LOW_P, PLATE_PID_INC_LOW_I, PLATE_PID_INC_LOW_D);
+      else
+        iPlatePid.SetTunings(PLATE_PID_INC_P, PLATE_PID_INC_I, PLATE_PID_INC_D);
     } else {
       iDecreasing = true;
       if (iTargetPlateTemp > PLATE_PID_DEC_HIGH_THRESHOLD)
@@ -464,7 +472,7 @@ void Thermocycler::ControlPeltier() {
         iPlatePid.ResetI();
       else
         iDecreasing = false;
-    }
+    } 
 
     if (iPeltierPwm > 0)
       newDirection = HEAT;

diff --git a/arduino/OpenPCR/thermocycler.h b/arduino/OpenPCR/thermocycler.h
@@ -64,7 +64,7 @@ class Thermocycler {
   const char* GetProgName() { return iszProgName; }
   Display* GetDisplay() { return ipDisplay; }
   ProgramComponentPool<Cycle, 4>& GetCyclePool() { return iCyclePool; }
-  ProgramComponentPool<Step, 20>& GetStepPool() { return iStepPool; }
+  ProgramComponentPool<Step, 30>& GetStepPool() { return iStepPool; }
 
   boolean Ramping() { return iRamping; }
   int GetPeltierPwm() { return iPeltierPwm; }
@@ -107,7 +107,7 @@ class Thermocycler {
   Display* ipDisplay;
   SerialControl* ipSerialControl;
   ProgramComponentPool<Cycle, 4> iCyclePool;
-  ProgramComponentPool<Step, 20> iStepPool;
+  ProgramComponentPool<Step, 30> iStepPool;
 
   // state
   ProgramState iProgramState;