PWM_fan: Use function API to access temperature

Instead of dealing with runtime lookup, use an external function to
look up the temperature value.

Author: willmmiles

usermods/PWM_fan/PWM_fan.cpp

@@ -1,13 +1,9 @@
 #include "wled.h"
 
-#if defined(USERMOD_DALLASTEMPERATURE) 
-#include "UsermodTemperature.h"
-#elif defined(USERMOD_SHT)
-#include "ShtUsermod.h"
-#else
-#error The "PWM fan" usermod requires "Dallas Temeprature" or "SHT" usermod to function properly.
-#endif
-
+// Function reference to read temperature; some other usermod must provide this
+namespace Temperature {
+  float getTemperatureC();
+}
 
 
 // PWM & tacho code curtesy of @KlausMu
@@ -44,12 +40,6 @@ class PWMFanUsermod : public Usermod {
     #endif
     bool lockFan = false;
 
-    #ifdef USERMOD_DALLASTEMPERATURE
-    UsermodTemperature* tempUM;
-    #elif defined(USERMOD_SHT)
-    ShtUsermod* tempUM;
-    #endif
-
     // configurable parameters
     int8_t  tachoPin          = TACHO_PIN;
     int8_t  pwmPin            = PWM_PIN;
@@ -157,16 +147,8 @@ class PWMFanUsermod : public Usermod {
       #endif
     }
 
-    float getActualTemperature(void) {
-      #if defined(USERMOD_DALLASTEMPERATURE) || defined(USERMOD_SHT)
-      if (tempUM != nullptr)
-        return tempUM->getTemperatureC();
-      #endif
-      return -127.0f;
-    }
-
     void setFanPWMbasedOnTemperature(void) {
-      float temp = getActualTemperature();
+      float temp = Temperature::getTemperatureC();
       // dividing minPercent and maxPercent into equal pwmvalue sizes
       int pwmStepSize = ((maxPWMValuePct - minPWMValuePct) * _pwmMaxValue) / (_pwmMaxStepCount*100);
       int pwmStep = calculatePwmStep(temp - targetTemperature);
@@ -193,12 +175,6 @@ class PWMFanUsermod : public Usermod {
     // gets called once at boot. Do all initialization that doesn't depend on
     // network here
     void setup() override {
-      #ifdef USERMOD_DALLASTEMPERATURE   
-      // This Usermod requires Temperature usermod
-      tempUM = (UsermodTemperature*) UsermodManager::lookup(USERMOD_ID_TEMPERATURE);
-      #elif defined(USERMOD_SHT)
-      tempUM = (ShtUsermod*) UsermodManager::lookup(USERMOD_ID_SHT);
-      #endif
       initTacho();
       initPWMfan();
       updateFanSpeed((minPWMValuePct * 255) / 100); // inital fan speed

usermods/Temperature/Temperature.cpp

@@ -354,8 +354,6 @@ const char *UsermodTemperature::getTemperatureUnit() {
   return degC ? "°C" : "°F";
 }
 
-UsermodTemperature* UsermodTemperature::_instance = nullptr;
-
 // strings to reduce flash memory usage (used more than twice)
 const char UsermodTemperature::_name[]         PROGMEM = "Temperature";
 const char UsermodTemperature::_enabled[]      PROGMEM = "enabled";
@@ -369,15 +367,19 @@ const char UsermodTemperature::_temperature[]  PROGMEM = "temperature";
 const char UsermodTemperature::_Temperature[]  PROGMEM = "/temperature";
 const char UsermodTemperature::_data_fx[]      PROGMEM = "Temperature@Min,Max;;!;01;pal=54,sx=255,ix=0";
 
+static UsermodTemperature temperature;
+REGISTER_USERMOD(temperature);
+
+// Effect function for temperature
 static uint16_t mode_temperature() {
   float low  = roundf(mapf((float)SEGMENT.speed, 0.f, 255.f, -150.f, 150.f));    // default: 15°C, range: -15°C to 15°C
   float high = roundf(mapf((float)SEGMENT.intensity, 0.f, 255.f, 300.f, 600.f));  // default: 30°C, range 30°C to 60°C
-  float temp = constrain(UsermodTemperature::getInstance()->getTemperatureC()*10.f, low, high);   // get a little better resolution (*10)
+  float temp = constrain(temperature.getTemperatureC()*10.f, low, high);   // get a little better resolution (*10)
   unsigned i = map(roundf(temp), (unsigned)low, (unsigned)high, 0, 248);
   SEGMENT.fill(SEGMENT.color_from_palette(i, false, false, 255));
   return FRAMETIME;
 }
 
 
-static UsermodTemperature temperature;
-REGISTER_USERMOD(temperature);
+// External API
+float Temperature::getTemperatureC() { return temperature.getTemperatureC(); }

usermods/Temperature/UsermodTemperature.h

@@ -72,12 +72,9 @@ class UsermodTemperature : public Usermod {
     void publishHomeAssistantAutodiscovery();
 #endif
 
-    static UsermodTemperature* _instance; // to overcome nonstatic getTemperatureC() method and avoid UsermodManager::lookup(USERMOD_ID_TEMPERATURE);
-
   public:
 
-    UsermodTemperature() { _instance = this; }
-    static UsermodTemperature *getInstance() { return UsermodTemperature::_instance; }
+    UsermodTemperature() {  }
 
     /*
      * API calls te enable data exchange between WLED modules
@@ -108,3 +105,8 @@ class UsermodTemperature : public Usermod {
     void appendConfigData() override;
 };
 
+
+// External API
+namespace Temperature {
+    float getTemperatureC();
+}

usermods/sht/ShtUsermod.h

@@ -69,3 +69,8 @@ class ShtUsermod : public Usermod
 
     uint16_t getId() { return USERMOD_ID_SHT; }
 };
+
+// External API
+namespace Temperature {
+    float getTemperatureC();
+}

usermods/sht/sht.cpp

@@ -413,3 +413,9 @@ const char* ShtUsermod::getUnitString() {
 
 static ShtUsermod sht;
 REGISTER_USERMOD(sht);
+
+
+/**
+ * External API
+ */
+float Temperature::getTemperatureC() { return sht.getTemperatureC(); }