pi without the d

include/pid_autotuner.h

@@ -27,10 +27,8 @@ public:
         useMaxSensorPv_(false),
         sessionStartMs_(0),
         phaseStartMs_(0),
-        resultKp_(PID_KP),
-        resultKi_(PID_KI),
-        resultKd_(PID_KD),
-        resultFanMixMax_(FAN_MIX_MAX_PWM) {}
+        resultKp_(HEAT_PI_KP),
+        resultKi_(HEAT_PI_KI) {}
 
   Phase phase() const { return phase_; }
 
@@ -77,7 +75,7 @@ public:
     Serial.print(preheatTargetC(), 1);
     Serial.print(F("-"));
     Serial.print(setpointC_, 1);
-    Serial.println(F("C avg"));
+    Serial.println(F("C avg (heat PI only)"));
     return true;
   }
 
@@ -98,20 +96,18 @@ public:
 
   float resultKp() const { return resultKp_; }
   float resultKi() const { return resultKi_; }
-  float resultKd() const { return resultKd_; }
-  uint8_t resultFanMixMax() const { return resultFanMixMax_; }
 
   Phase update(float avgTempC, float maxTempC, float spreadC, uint32_t nowMs, float &heaterDutyOut,
                uint8_t &fanPwmOut) {
     heaterDutyOut = 0.0f;
-    fanPwmOut = FAN_HEAT_MIN_PWM;
+    fanPwmOut = AUTOTUNE_PREHEAT_FAN_PWM;
 
     if (phase_ == Phase::Idle || phase_ == Phase::Done || phase_ == Phase::Failed) {
       return phase_;
     }
 
-    if (maxTempC >= TARGET_MAX_C - 1.0f) {
-      fail(F("autotune: abort — max sensor at safety limit"));
+    if (maxTempC >= EMERGENCY_MAX_TEMP_C) {
+      fail(F("autotune: abort — max sensor at emergency limit"));
       return phase_;
     }
 
@@ -140,11 +136,6 @@ public:
       return phase_;
     }
 
-    if (nowMs - sessionStartMs_ > AUTOTUNE_SESSION_TIMEOUT_MS) {
-      fail(F("autotune: abort — session timeout"));
-      return phase_;
-    }
-
     if (cycleCount_ == 0 && nowMs - phaseStartMs_ > AUTOTUNE_RELAY_STALL_MS) {
       Serial.print(F("autotune: relay stalled — avg "));
       Serial.print(avgTempC, 1);
@@ -264,7 +255,6 @@ private:
     const float ku = (4.0f * 100.0f) / (PI * avgAmplitude);
     resultKp_ = 0.45f * ku;
     resultKi_ = resultKp_ / (2.2f * avgPeriodSec);
-    resultKd_ = resultKp_ * avgPeriodSec / 6.3f;
 
     if (resultKp_ < 0.5f) {
       resultKp_ = 0.5f;
@@ -273,30 +263,15 @@ private:
       resultKi_ = resultKp_ / 3.0f;
     }
 
-    resultFanMixMax_ = FAN_MIX_MAX_PWM;
-    const float spreadAvg =
-        spreadSamples_ > 0 ? spreadSum_ / static_cast<float>(spreadSamples_) : GOOD_SPREAD_C;
-    if (spreadAvg > GOOD_SPREAD_C) {
-      const float boost = 1.0f + ((spreadAvg - GOOD_SPREAD_C) / 10.0f);
-      int boosted = static_cast<int>(static_cast<float>(FAN_MIX_MAX_PWM) * boost);
-      if (boosted > static_cast<int>(FAN_MAX_PWM) - 20) {
-        boosted = FAN_MAX_PWM - 20;
-      }
-      resultFanMixMax_ = static_cast<uint8_t>(boosted);
-    }
-
     phase_ = Phase::Done;
     Serial.print(F("autotune: done in "));
     Serial.print((nowMs - sessionStartMs_) / 1000UL);
     Serial.println(F("s"));
-    Serial.print(F("  Kp="));
+    Serial.print(F("  heat Kp="));
     Serial.print(resultKp_, 3);
     Serial.print(F(" Ki="));
-    Serial.print(resultKi_, 4);
-    Serial.print(F(" Kd="));
-    Serial.print(resultKd_, 3);
-    Serial.print(F(" fanMixMax="));
-    Serial.println(resultFanMixMax_);
+    Serial.println(resultKi_, 4);
+    Serial.println(F("  tune mix PI separately: mixpi <Kp> <Ki>"));
   }
 
   void fail(const __FlashStringHelper *reason) {
@@ -325,6 +300,4 @@ private:
   uint32_t phaseStartMs_;
   float resultKp_;
   float resultKi_;
-  float resultKd_;
-  uint8_t resultFanMixMax_;
 };