SGP wrong temp workaround

ardufocus/ardufocus.cpp

@@ -65,6 +65,7 @@ int main(void)
   // ADC init routine ---------------------------------------------------------
   // --------------------------------------------------------------------------
   Analog::setup();
+  Analog::read(THERMISTOR_ADC_CHANNEL);
 
 
   // --------------------------------------------------------------------------

ardufocus/config.h

@@ -91,6 +91,15 @@
 // verify if the overall system accuracy increases.
 //#define COMPRESS_HALF_STEPS
 
+
+// According to the Moonlite protocol the temperature probe should only be read
+// when the command ":C#" is received but some applications, such as SGP, seems
+// not to respect this and only call the get temperature command ":GT#" which
+// means the temperature will never get updated and the last value is always
+// returned, either it is valid or not. Enabling the following option will force
+// the temperature gathering process on every temperature read command.
+// #define START_TEMP_CONVERSION_ON_EVERY_GET
+
 // ----------------------------------------------------------------------------
 // Temperature sensor configuration -------------------------------------------
 // ----------------------------------------------------------------------------

ardufocus/protocol.cpp

@@ -78,6 +78,10 @@ void protocol::process(const char *cmd)
           break;
 
         case 'T': // Get the current temperature
+          #ifdef START_TEMP_CONVERSION_ON_EVERY_GET
+            Analog::read(THERMISTOR_ADC_CHANNEL);
+          #endif
+
           sprintf(str, "%04X#", static_cast<int16_t>(util::steinhart(g_ambient)) << 1);
           Log::string(str);
           break;

ardufocus/version.h

@@ -21,8 +21,8 @@
 #define __VERSION_H__
 
  // Program version and release
-#define ARDUFOCUS_VERSION       "0.1c"
-#define ARDUFOCUS_VERSION_BUILD "20180315"
+#define ARDUFOCUS_VERSION       "0.1d"
+#define ARDUFOCUS_VERSION_BUILD "20180517"
 #define ARDUFOCUS_URL           "https://github.com/jbrazio/ardufocus"
 
 #endif