Many changes.

1. Migrate from microDS18B20 to DallasTemperature
2. Refactoring of sensors: added an external temperature sensor inside the house, added an "offset" parameter for sensors
3. Fixed PID
4. New parameters added:
- settings.heating.minTemp
- settings.heating.maxTemp
- settings.dhw.minTemp
- settings.dhw.maxTemp
- settings.pid.minTemp
- settings.pid.maxTemp
- settings.sensors.outdoor.type
- settings.sensors.outdoor.pin
- settings.sensors.outdoor.offset
- settings.sensors.indoor.type
- settings.sensors.indoor.pin
- settings.sensors.indoor.offset
5. Fixed and updated HomeAssistantHelper
7. Added check for validity of settings. After some updates, the settings may be reset to default, but this will prevent the settings from being distorted.

src/defines.h

@@ -1,4 +1,4 @@
-#define OT_GATEWAY_VERSION          "1.2.1"
+#define OT_GATEWAY_VERSION          "1.3.0"
 #define AP_SSID                     "OpenTherm Gateway"
 #define AP_PASSWORD                 "otgateway123456"
 #define USE_TELNET
@@ -9,9 +9,8 @@
 
 #define OPENTHERM_OFFLINE_TRESHOLD  10
 
-#define DS18B20_PIN                 2
-#define DS18B20_INTERVAL            5000
-#define OUTDOOR_SENSOR_FILTER_K     0.15
+#define EXT_SENSORS_INTERVAL        5000
+#define EXT_SENSORS_FILTER_K        0.15
 #define DS_CHECK_CRC                true
 #define DS_CRC_USE_TABLE            true
 
@@ -19,6 +18,7 @@
 #define LED_OT_RX_PIN               15
 
 #define CONFIG_URL                  "http://%s/"
+#define SETTINGS_VALID_VALUE        "stvalid" // only 8 chars!
 
 
 #ifdef USE_TELNET