diff --git a/main/ZsensorDS1820.ino b/main/ZsensorDS1820.ino
index 896c8c2..61c78ff 100644
--- a/main/ZsensorDS1820.ino
+++ b/main/ZsensorDS1820.ino
@@ -128,11 +128,11 @@ void MeasureDS1820Temp() {
 
   // trigger temperature conversion some time before actually
   // calling getTempC() to make reading temperatures non-blocking
-  if (!triggeredConversion && (millis() > (timeDS1820 + (DS1820_INTERVAL_SEC * 1000) - DS1820_CONV_TIME))) {
+  if (!triggeredConversion && ((millis() - timeDS1820) > (DS1820_INTERVAL_SEC * 1000UL - DS1820_CONV_TIME))) {
     Log.trace(F("DS1820: Trigger temperature conversion..." CR));
     ds1820.requestTemperatures();
     triggeredConversion = true;
-  } else if (triggeredConversion && (millis() > (timeDS1820 + (DS1820_INTERVAL_SEC * 1000)))) {
+  } else if (triggeredConversion && ((millis() - timeDS1820) > DS1820_INTERVAL_SEC * 1000UL)) {
     timeDS1820 = millis();
     triggeredConversion = false;
 
@@ -148,8 +148,8 @@ void MeasureDS1820Temp() {
         if (current_temp[i] == -127) {
           Log.error(F("DS1820: Device %s currently disconnected!" CR), (char*)ds1820_addr[i].c_str());
         } else if (DS1820_ALWAYS || current_temp[i] != persisted_temp[i]) {
-          DS1820data["tempc"] = (float)DallasTemperature::toFahrenheit(current_temp[i]);
-          DS1820data["tempf"] = (float)current_temp[i];
+          DS1820data["tempf"] = (float)DallasTemperature::toFahrenheit(current_temp[i]);
+          DS1820data["tempc"] = (float)current_temp[i];
 
           if (DS1820_DETAILS) {
             DS1820data["type"] = ds1820_type[i];
diff --git a/main/config_DS1820.h b/main/config_DS1820.h
index 52d6ba2..399c55c 100644
--- a/main/config_DS1820.h
+++ b/main/config_DS1820.h
@@ -34,10 +34,10 @@ extern void pubOneWire_HADiscovery();
 #define OW_TOPIC            "/OneWiretoMQTT/ds1820"
 #define OW_MAX_SENSORS      8 // query max. sensors on 1-wire bus
 #define DS1820_ALWAYS       true // if false only published current temperature if has changed from previous reading
-#define DS1820_INTERVAL_SEC 60 // time between DS1820 readings (seconds)
+#define DS1820_INTERVAL_SEC 60UL // time between DS1820 readings (seconds)
 #define DS1820_RESOLUTION   10 // conversion times: 9 bit (93.75 ms), 10 bit (187.5 ms), 11 bit (375 ms), 12 bit (750 ms)
 #define DS1820_DETAILS      true // publish extented info for each sensor (resolution, address, type)
-#define DS1820_CONV_TIME    2000 // trigger conversion before requesting temperature readings (ms)
+#define DS1820_CONV_TIME    2000UL // trigger conversion before requesting temperature readings (ms)
 /*-------------------PIN DEFINITIONS----------------------*/
 
 #ifndef DS1820_OWBUS_GPIO