Added fan support, but calculation still needs to be verified!

cm_heatsink_emulator.c

@@ -9,35 +9,82 @@
 
 #define EULER_NUM 2.7182818284590452353602
 
-static float deltaTempElement(cm_heatsink_thermalElement_t *element, float temperature, float power){
+static int isStructOk(cm_heatsinkEmul_t *inst){
+	if(inst == NULL)return 0;
+	if(inst->thermalElements == NULL)return 0;
+	if(inst->thermalElements_Counts == 0)return 0;
 
-	return temperature + (power * element->R_th);
+	return 1;
 
 }
 
-float cm_heatsinkEmul_getRespon(cm_heatsinkEmul_t *inst, float dtime){
+static float deltaTempElement(cm_heatsink_thermalElement_t *element, float temperature, float power, float fan_speed){
+
+	if((fan_speed > 0.0) && (fan_speed <= 1.0)){
+
+		float dtemp = element->R_th_MaxFan - element->R_th_MinFan;
+		return power * (element->R_th_MinFan + (dtemp * fan_speed));
+
+	}else{
+		// Kelvin = Watt * K/W
+		return (power * element->R_th);
+	}
+
+}
+
+static float updateCthFromFan(cm_heatsink_thermalElement_t *element, float fan_speed){
+
+	if((fan_speed > 0.0) && (fan_speed <= 1.0)){
+
+		float dc = element->C_th_MaxFan - element->C_th_MinFan;
+		return (element->C_th_MinFan + (dc * fan_speed));
+
+	}else{
+		return element->C_th;
+	}
+
+}
+
+int cm_heatsinkEmul_iterate(cm_heatsinkEmul_t *inst, float dtime){
+	if(!isStructOk(inst)) return 1;
 
 	float dtemp = inst->ambientTemp;
 
-	for(int i = inst->thermalElements_Counts; i > 0; i--){
+	// We begin from ambient temperature and move up towards heat source.
+	for(int i = (inst->thermalElements_Counts-1); i >= 0; i--){
 
-		dtemp+= deltaTempElement(&inst->thermalElements[i], dtemp, inst->power);
+		// Calculate temperature until we reach requested element!
+		dtemp += deltaTempElement(&inst->thermalElements[i], dtemp, inst->power, inst->fan_speed);
+
+		float C_th = updateCthFromFan(&inst->thermalElements[i], inst->fan_speed);
+
+		// Do so the temperature has the responsetime as the heatsink.
+		inst->thermalElements[i].temperature = inst->thermalElements[i].temperature + (1.0 / C_th) * (dtemp - inst->thermalElements[i].temperature) * dtime;
 	}
-
-	printf("dTemp: %f", dtemp);
-
-	//inst->heatsinkTemperature = inst->heatsinkTemperature + (1.0 / inst->C_th) * (pj5_ThermEmul_Heatsink_RespVal(inst) - inst->heatsinkTemperature) * dt;
-
-		return inst->heatsinkTemperature;
+	return 0;
 
 }
 
+float cm_heatsinkEmul_getElementTemp(cm_heatsinkEmul_t *inst, int element_idx){
+	if(!isStructOk(inst)) return 0.0;
+	if(element_idx > (inst->thermalElements_Counts-1)) return 0.0;
+	return inst->thermalElements[element_idx].temperature;
 
-int cm_heatsinkEmul_init(cm_heatsinkEmul_t *inst, cm_heatsink_thermalElement_t *elements, int elements_Count, float power, float ambientTemp){
+}
 
-	if(inst == NULL)return 0;
-	if(elements == NULL)return 0;
-	if(elements_Count == 0)return 0;
+int cm_heatsinkEmul_setFan(cm_heatsinkEmul_t *inst, float fan_speed){
+	if(!isStructOk(inst)) return 1;
+	inst->fan_speed = fan_speed;
+
+	return 0;
+}
+
+
+int cm_heatsinkEmul_init(cm_heatsinkEmul_t *inst, cm_heatsink_thermalElement_t *elements, int elements_Count, float C_th, float power, float ambientTemp){
+
+	if(inst == NULL)return 1;
+	if(elements == NULL)return 1;
+	if(elements_Count == 0)return 1;
 
 	inst->thermalElements = elements;
 	inst->thermalElements_Counts = elements_Count;
@@ -45,6 +92,14 @@ int cm_heatsinkEmul_init(cm_heatsinkEmul_t *inst, cm_heatsink_thermalElement_t *
 	inst->power = power;
 	inst->ambientTemp = ambientTemp;
 
+	// Dynamic values
+	inst->fan_speed = 0;
+
+	// Assume all elements is equal to ambient before we start!
+	for(int i = (inst->thermalElements_Counts-1); i >= 0; i--){
+		inst->thermalElements[i].temperature = inst->ambientTemp;
+	}
+
 	return 0;
 
 }

cm_heatsink_emulator.h

@@ -12,7 +12,21 @@
 
 typedef struct {
 	char label[32];
-	float R_th; // In Kelvin/Watt or Celsius/Watt (you can mix!)
+	union{
+		float R_th; // In Kelvin/Watt or Celsius/Watt (you can mix!)
+		float R_th_MinFan; // In case you need to emulate a fan
+	};
+	float R_th_MaxFan; // In case you need to emulate a fan
+
+	union{
+		float C_th;
+		float C_th_MinFan;
+	};
+	float C_th_MaxFan;
+
+
+	// Dynamic
+	float temperature;
 
 }cm_heatsink_thermalElement_t;
 
@@ -23,15 +37,15 @@ typedef struct {
 
 	float power;
 	float ambientTemp;
-	float C_th; // Thermal capacity
 
 	// Dynamic
-	float heatsinkTemperature;
+	float prev_time;
+	float fan_speed;
 
 }cm_heatsinkEmul_t;
 
-float cm_heatsinkEmul_getRespon(cm_heatsinkEmul_t *inst, float dt);
-int cm_heatsinkEmul_init(cm_heatsinkEmul_t *inst, cm_heatsink_thermalElement_t *elements, int elements_Count, float power, float ambientTemp);
-
+int cm_heatsinkEmul_iterate(cm_heatsinkEmul_t *inst, float dtime);
+float cm_heatsinkEmul_getElementTemp(cm_heatsinkEmul_t *inst, int element_idx);
+int cm_heatsinkEmul_init(cm_heatsinkEmul_t *inst, cm_heatsink_thermalElement_t *elements, int elements_Count, float C_th, float power, float ambientTemp);
 
 #endif /* CM_HEATSINK_EMULATOR_H_ */