diff --git a/greenhouseheating.ino b/greenhouseheating.ino
index 1198adf..1aaf281 100644
--- a/greenhouseheating.ino
+++ b/greenhouseheating.ino
@@ -2,7 +2,6 @@
 #include <Arduino.h>
 #include <Thread.h>                    // ArduinoThread
 #include <DHT.h>                       // DHT Sensor Library by Adafruit 1.2.3 (!!! 1.3 not working)
-#include <OneWire.h>                   // DS18B20 temp sensor
 #include <DS1307RTC.h>                 // A basic DS1307 library that returns time as a time_t
 #include <SevenSegmentExtended.h>      // Extended TM1637 library https://github.com/bremme/arduino-tm1637
 
@@ -195,4 +194,4 @@ void serStr(const char* serString) {
   Serial.write('/');
   Serial.print(year());
   Serial.println();
-}
\ No newline at end of file
+}
diff --git a/greenhouseheating_light/greenhouseheating_light.ino b/greenhouseheating_light/greenhouseheating_light.ino
new file mode 100644
index 0000000..9020750
--- /dev/null
+++ b/greenhouseheating_light/greenhouseheating_light.ino
@@ -0,0 +1,110 @@
+// Greenhouse heating system - Light version
+#include <Arduino.h>
+#include <Thread.h>                    // ArduinoThread
+#include <DHT.h>                       // DHT Sensor Library by Adafruit 1.2.3 (!!! 1.3 not working)
+
+const byte relay = 2;                  // Relay PIN
+#define DHTPIN 3                       // PIN DHT
+
+DHT dht(DHTPIN, DHT11);                // DHT-22 - AM2302 init
+
+int minTemp = 11;                      // Minimum temperature for relay (on)
+int led = 13;
+int maxTemp = 14;                      // Maximum temperature for relay (off)
+long relayWorkingTime = 600000;        // 10min - minimun working time
+
+int tempThreadMs = 10000;              // checkTemp thread interval
+int buttonThreadMs = 200;              // pressButton thread interval
+int buttonState = 0;                   // Button state
+int buttonView = 0;                    // Button viewing state
+int relayState = 0;                    // Relay state
+long previousRelayChanged = 0;         // Last time relay state changed
+long buttonPressed = 0;                // Button ms pressed counter
+long previousButtonMillis = 0;         // Last time button pressing
+long buttonInterval = 10000;           // Interval for highlighting 4-Digit Display after pressing button
+
+// Threads:
+Thread checkTempThread = Thread();     // Create thread for temperature state checking
+
+void setup() {
+  Serial.begin(9600);                  // Initializes the Serial connection @ 9600 baud for debug
+  serStr("starting setup...");
+  while (!Serial);                     // Wait until Arduino Serial Monitor opens
+  dht.begin();
+  pinMode(led, OUTPUT);     
+  pinMode(relay, OUTPUT);
+  digitalWrite(relay, HIGH);
+  // Button state cheking thread:
+  checkTempThread.onRun(checkTemp);
+  checkTempThread.setInterval(tempThreadMs); // Interval for checking temperature
+  delay(5000);                         // 5 second delay before display off and setup complete
+  serStr("...setup finished");
+}
+
+void loop() {
+  // Threads init:
+  if (checkTempThread.shouldRun())
+    checkTempThread.run();
+  // Check RTC.
+}
+
+// Check temperature thread
+void checkTemp() {
+  unsigned long currentMillis = millis();
+  if (((currentMillis - previousRelayChanged) > relayWorkingTime) || (previousRelayChanged == 0)) {
+    float tempFloat;
+    readDHTtemp(&tempFloat);
+    if (tempFloat != tempFloat) {
+      serStr("TEMPERATURE is Not A Number");
+      for (int i = 0; i < 23; i++) {
+        digitalWrite(relay, HIGH);
+        digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
+        delay(333);               // wait for a second
+        digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
+        delay(444);     
+      }
+    } else {
+      int tempInt = (int)tempFloat;
+      if ((tempInt < minTemp) && (relayState == 0)) {
+        serStr("low temperature - heating on");
+        digitalWrite(relay, LOW);
+        previousRelayChanged = currentMillis;
+        relayState = 1;
+      }
+      if ((tempInt > maxTemp) && (relayState == 1)) {
+        serStr("high temperature - heating off");
+        digitalWrite(relay, HIGH);
+        previousRelayChanged = currentMillis;
+        relayState = 0;
+      }
+    }
+  }
+  String string = "";
+  String stringToPrint = "";
+  float tempFloat;
+  float humFloat;
+  readDHTtemp(&tempFloat);
+  string = "TEMPERATURE ";
+  stringToPrint = string + tempFloat;
+  serStr(stringToPrint);
+}
+
+// DHT Temperature
+void readDHTtemp(float *a) {
+  float t = dht.readTemperature();
+  *a = t;
+}
+ 
+// DHT Humidity
+void readDHThum(float *a) {
+  float h = dht.readHumidity();
+  *a = h;
+}
+
+// Send string to serial monitor with millis() counter and date/time
+void serStr(String serString) {
+  long millisTime = millis();
+  String delimiter = "|";
+  String stringToPrint = millisTime + delimiter + serString;
+  Serial.println(stringToPrint);
+}