From b8f11741b559c0bd46693ce4a74bf0ebfeee8a17 Mon Sep 17 00:00:00 2001
From: Matthew Kennedy <matthewkennedy@outlook.com>
Date: Tue, 20 Jun 2023 17:26:54 -0700
Subject: [PATCH] heater uses sampling class

---
 firmware/heater_control.cpp |  8 ++--
 firmware/sampling.cpp       | 74 +++++++++++++++++++++++--------------
 firmware/sampling.h         |  2 +
 3 files changed, 54 insertions(+), 30 deletions(-)

diff --git a/firmware/heater_control.cpp b/firmware/heater_control.cpp
index b34c06f..487f0db 100644
--- a/firmware/heater_control.cpp
+++ b/firmware/heater_control.cpp
@@ -257,16 +257,18 @@ static void HeaterThread(void*)
         auto heaterAllowState = GetHeaterAllowed();
 
         for (i = 0; i < AFR_CHANNELS; i++) {
+            const auto& sampler = GetSampler(i);
+
             heater_state &s = state[i];
 
             // Read sensor state
-            float heaterEsr = GetSensorInternalResistance(s.ch);
-            float sensorTemperature = GetSensorTemperature(s.ch);
+            float heaterEsr = sampler.GetSensorInternalResistance();
+            float sensorTemperature = sampler.GetSensorTemperature();
 
             // If we haven't heard from rusEFI, use the internally sensed 
             // battery voltage instead of voltage over CAN.
             float batteryVoltage = heaterAllowState == HeaterAllow::Unknown
-                                        ? GetInternalBatteryVoltage(s.ch)
+                                        ? sampler.GetInternalBatteryVoltage()
                                         : GetRemoteBatteryVoltage();
 
             // Run the state machine
diff --git a/firmware/sampling.cpp b/firmware/sampling.cpp
index ec2ebbc..c43a653 100644
--- a/firmware/sampling.cpp
+++ b/firmware/sampling.cpp
@@ -25,15 +25,18 @@ struct Sampler : public ISampler {
 public:
     void ApplySample(AnalogChannelResult& result, float virtualGroundVoltageInt);
 
-    float GetNernstDc() const override {
+    float GetNernstDc() const override
+    {
         return nernstDc;
     }
 
-    float GetNernstAc() const override {
+    float GetNernstAc() const override
+    {
         return nernstAc;
     }
 
-    float GetPumpNominalCurrent() const override {
+    float GetPumpNominalCurrent() const override
+    {
         // Gain is 10x, then a 61.9 ohm resistor
         // Effective resistance with the gain is 619 ohms
         // 1000 is to convert to milliamperes
@@ -41,13 +44,45 @@ public:
         return pumpCurrentSenseVoltage * ratio;
     }
 
-    float GetInternalBatteryVoltage() const override {
+    float GetInternalBatteryVoltage() const override
+    {
         // Dual HW can measure heater voltage for each channel
         // by measuring voltage on Heater- while FET is off
         // TODO: rename function?
         return internalBatteryVoltage;
     }
 
+    float GetSensorTemperature() const override
+    {
+        float esr = GetSensorInternalResistance();
+
+        if (esr > 5000)
+        {
+            return 0;
+        }
+
+        switch (GetSensorType()) {
+            case SensorType::LSU49:
+                return interpolate2d(esr, lsu49TempBins, lsu49TempValues);
+            case SensorType::LSU42:
+                return interpolate2d(esr, lsu42TempBins, lsu42TempValues);
+            case SensorType::LSUADV:
+                return interpolate2d(esr, lsuAdvTempBins, lsuAdvTempValues);
+        }
+
+        return 0;
+    }
+
+    float GetSensorInternalResistance() const override
+    {
+        // Sensor is the lowside of a divider, top side is GetESRSupplyR(), and 3.3v AC pk-pk is injected
+        float totalEsr = GetESRSupplyR() / (VCC_VOLTS / GetNernstAc() - 1);
+
+        // There is a resistor between the opamp and Vm sensor pin.  Remove the effect of that
+        // resistor so that the remainder is only the ESR of the sensor itself
+        return totalEsr - VM_RESISTOR_VALUE;
+    }
+
 private:
     float r_2 = 0;
     float r_3 = 0;
@@ -60,6 +95,11 @@ private:
 
 static Sampler samplers[AFR_CHANNELS];
 
+ISampler& GetSampler(int ch)
+{
+    return samplers[ch];
+}
+
 constexpr float f_abs(float x)
 {
     return x > 0 ? x : -x;
@@ -139,35 +179,15 @@ float GetNernstAc(int ch)
     return samplers[ch].GetNernstAc();
 }
 
+// TODO: remove these helpers
 float GetSensorInternalResistance(int ch)
 {
-    // Sensor is the lowside of a divider, top side is GetESRSupplyR(), and 3.3v AC pk-pk is injected
-    float totalEsr = GetESRSupplyR() / (VCC_VOLTS / GetNernstAc(ch) - 1);
-
-    // There is a resistor between the opamp and Vm sensor pin.  Remove the effect of that
-    // resistor so that the remainder is only the ESR of the sensor itself
-    return totalEsr - VM_RESISTOR_VALUE;
+    return samplers[ch].GetSensorInternalResistance();
 }
 
 float GetSensorTemperature(int ch)
 {
-    float esr = GetSensorInternalResistance(ch);
-
-    if (esr > 5000)
-    {
-        return 0;
-    }
-
-    switch (GetSensorType()) {
-        case SensorType::LSU49:
-            return interpolate2d(esr, lsu49TempBins, lsu49TempValues);
-        case SensorType::LSU42:
-            return interpolate2d(esr, lsu42TempBins, lsu42TempValues);
-        case SensorType::LSUADV:
-            return interpolate2d(esr, lsuAdvTempBins, lsuAdvTempValues);
-    }
-
-    return 0;
+    return samplers[ch].GetSensorTemperature();
 }
 
 float GetNernstDc(int ch)
diff --git a/firmware/sampling.h b/firmware/sampling.h
index cdf2fb7..fbdfa87 100644
--- a/firmware/sampling.h
+++ b/firmware/sampling.h
@@ -6,6 +6,8 @@ struct ISampler
     virtual float GetNernstAc() const = 0;
     virtual float GetPumpNominalCurrent() const = 0;
     virtual float GetInternalBatteryVoltage() const = 0;
+    virtual float GetSensorTemperature() const = 0;
+    virtual float GetSensorInternalResistance() const = 0;
 };
 
 // Get the sampler for a particular channel