diff --git a/include/sensor_ldr.cpp b/include/sensor_ldr.cpp
new file mode 100644
index 0000000..a1e538e
--- /dev/null
+++ b/include/sensor_ldr.cpp
@@ -0,0 +1,89 @@
+// High/Low Output LDR Sensor
+// For example: RCWL-0516 (needs 5v input (gnd, vin), 3.3v output level. high for 2seconds when movement detected)
+#include "sensor_ldr.h"
+
+
+Sensor_LDR::Sensor_LDR(int p)
+{
+  pin=p;
+  sensordata data;
+}
+
+void Sensor_LDR::init() //Things to be done during setup()
+{    
+  Serial.println("initializing LDR");
+  pinMode(pin, INPUT);
+  analogRead(pin); //first reading could be false
+  init_ok=true;     
+}
+
+//Also called during setup()
+void Sensor_LDR::setSettings(unsigned long senddelaymax, unsigned long readdelay)
+{
+    data.senddelaymax=senddelaymax;
+    data.readdelay=readdelay;
+}
+
+//Called during setup
+void Sensor_LDR::advertise(HomieNode& p_sensorNode)
+{
+    sensorNode = &p_sensorNode;
+    sensorNode->advertise("light");
+    
+}
+
+void Sensor_LDR::sensorloop()
+{
+  if (init_ok) {
+    sensordata &d=data;
+    
+    bool _changed=false;
+    if (millis() >= (d.lastreadtime+d.readdelay)) {
+      d.value = get_lux(in_ldr, out_ldr, LDR_ARRAYSIZE)/10.0; //read light level in lux
+      if (fabs(d.lastsentvalue-d.value)>=d.minchange){
+        _changed=true;
+      }
+      d.lastreadtime=millis();
+    }
+
+    if (_changed || millis() >= (d.lastsent+d.senddelaymax)) {
+      Serial.print("Sending LDR. reason=");
+      if (_changed) Serial.println("change"); else Serial.println("time");
+
+      Homie.getLogger() << "light " << ": " << d.value << endl;
+      sensorNode->setProperty("light").send(String(d.value));
+      d.lastsentvalue=d.value;
+      
+      d.lastsent=millis();
+    }
+  }
+}
+
+
+//////////////////////////////////////////////////////////////////////////////
+// Calculate lux based on rawADC reading from LDR returns value in lux/10
+//////////////////////////////////////////////////////////////////////////////
+//quelle: https://groups.google.com/forum/#!topic/souliss/1kMAltPB2ME[1-25]
+int Sensor_LDR::get_lux(const unsigned int* _in, const unsigned int* _out, byte size)
+{
+  // take care the value is within range
+  // val = constrain(val, _in[0], _in[size-1]);
+  unsigned int val = analogRead(pin);
+  #ifdef DEBUG   //DEBUG++++++++++++++++
+        Serial.print("LDR RAW=: ");
+        Serial.println(val);
+  #endif
+
+  if (val <= _in[0]) return _out[0];
+  if (val >= _in[size-1]) return _out[size-1];
+
+  // search right interval
+  byte pos = 1;  // _in[0] allready tested
+  while(val > _in[pos]) pos++;
+
+  // this will handle all exact "points" in the _in array
+  if (val == _in[pos]) return _out[pos];
+
+  // interpolate in the right segment for the rest
+  return map(val, _in[pos-1], _in[pos], _out[pos-1], _out[pos]);
+}
\ No newline at end of file
diff --git a/include/sensor_ldr.h b/include/sensor_ldr.h
new file mode 100644
index 0000000..a8f494c
--- /dev/null
+++ b/include/sensor_ldr.h
@@ -0,0 +1,43 @@
+#ifndef SENSOR_LDR_H
+#define SENSOR_LDR_H
+
+#include "sensordata.h"
+#include <Homie.h>
+
+
+
+class Sensor_LDR
+{
+    
+private:
+    HomieNode *sensorNode; //reference to HomieNode
+
+    int pin;
+
+    struct sensordata data; //struct values are changed in setup()
+
+    int get_lux(const unsigned int* _in, const unsigned int* _out, byte size);
+
+
+    
+    //wemos d1 mini, black wire of ldr connects to A0 with 10k to gnd. red wire connects with 1k to gnd and 2k2 to 3v3
+    #define LDRARRAYSIZE 18
+    const unsigned int out_ldr[18] = {0, 30, 50,  60,  130, 170, 250, 420, 780, 1300,2600, 5000, 5350, 7700, 10900, 12000, 17000,20000};  // x10  (i.e. gets later divided by 10)
+    const unsigned int in_ldr[18]  = {0, 12, 100, 150, 350, 400, 450, 650, 730,  780, 840, 930,  948 , 970,  993,   1005,  1019, 1023};  // 0 - 1023
+    
+
+    
+    bool init_ok;
+public:
+    Sensor_LDR(int p);
+
+
+    void init();
+    void setSettings(unsigned long senddelaymax, unsigned long readdelay);
+    void advertise(HomieNode& p_sensorNode);
+    void sensorloop();
+    
+};
+
+#endif
+
diff --git a/platformio.ini b/platformio.ini
index f0271b6..dbd352c 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -82,8 +82,6 @@ monitor_port = /dev/ttyUSB0
 monitor_speed = 115200
 
 build_flags =
-    -D SENSOR_HCSR501
-    -D SENSOR_HCSR501_PIN=D0
 
 
     -D SENSOR_RADAR
@@ -91,6 +89,9 @@ build_flags =
     -D SENSOR_RADAR_readdelay=100
     -D SENSOR_RADAR_senddelaymax=1000*60*10
 
+    -D SENSOR_LDR
+    -D SENSOR_LDR_PIN=A0
+
 
 lib_deps = 
     ArduinoJson@6.16.1 #dependency of homie. using older version because of "ambiguous overload for operator|" error
@@ -120,10 +121,10 @@ build_flags =
 
     -D SENSOR_LDR
     -D SENSOR_LDR_CALIB1
-    -D LDR_PIN=A0
-    -D dataLDR_minchange=10.0
-    -D dataLDR_readdelay=1000*2
-    -D dataLDR_senddelaymax=1000*60*1
+    -D SENSOR_LDR_PIN=A0
+    -D SENSOR_LDR_minchange=10.0
+    -D SENSOR_LDR_readdelay=1000*2
+    -D SENSOR_LDR_senddelaymax=1000*60*1
 
 
 lib_deps = 
diff --git a/src/main.cpp b/src/main.cpp
index 8b720fa..13c69e5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -173,17 +173,19 @@
   #endif
 #endif
 
-
 #ifdef SENSOR_LDR
-  struct sensordata dataLDR;
-  float value_ldr=0;
-  #ifdef SENSOR_LDR_CALIB1
-    #define LDRARRAYSIZE 18
-    //black wire of ldr connects to A0 with 10k to gnd. red wire connects with 1k to gnd and 2k2 to 3v3
-    static const unsigned int out_ldr[] = {0, 30, 50,  60,  130, 170, 250, 420, 780, 1300,2600, 5000, 5350, 7700, 10900, 12000, 17000,20000};  // x10  (i.e. gets later divided by 10)
-    static const unsigned int in_ldr[]  = {0, 12, 100, 150, 350, 400, 450, 650, 730,  780, 840, 930,  948 , 970,  993,   1005,  1019, 1023};  // 0 - 1023
+  #include "sensor_ldr.cpp"
+  Sensor_LDR sensor_ldr(SENSOR_LDR_PIN);
+
+  #ifndef SENSOR_LDR_minchange
+    #define SENSOR_LDR_minchange 10.0
+  #endif
+  #ifndef SENSOR_LDR_senddelaymax
+    #define SENSOR_LDR_senddelaymax 1000*60*1
+  #endif
+  #ifndef SENSOR_LDR_readdelay
+    #define SENSOR_LDR_readdelay 1000*2
   #endif
-  int get_lux(const unsigned int* _in, const unsigned int* _out, byte size); //for analog ldr light calculation
 #endif
 
 #ifdef SENSOR_MHZ19
@@ -406,17 +408,8 @@ void setup() {
   #endif
 
   #ifdef SENSOR_LDR
-    Serial.println("initializing ldr");
-    pinMode(LDR_PIN, INPUT); //ldr
-    #ifdef dataLDR_readdelay
-    dataLDR.readdelay=dataLDR_readdelay;
-    #endif
-    #ifdef dataLDR_senddelaymax
-    dataLDR.senddelaymax=dataLDR_senddelaymax;
-    #endif
-    #ifdef dataLDR_minchange
-    dataLDR.minchange=dataLDR_minchange;
-    #endif
+    sensor_ldr.init();
+    sensor_ldr.setSettings(SENSOR_RADAR_senddelaymax,SENSOR_RADAR_readdelay);
   #endif
 
   #ifdef SENSOR_MHZ19
@@ -570,8 +563,7 @@ void setup() {
   #endif
 
   #ifdef SENSOR_LDR
-    sensorNode.advertise("light");
-    analogRead(LDR_PIN); //first reading could be false
+    sensor_ldr.advertise(sensorNode);
   #endif
 
 
@@ -627,36 +619,6 @@ void loop() {
   Homie.loop();  
 }
 
-
-#ifdef SENSOR_LDR
-void loop_LDR()
-{
-  sensordata &d=dataLDR;
-  
-  bool _changed=false;
-  if (millis() >= (d.lastreadtime+d.readdelay)) {
-    value_ldr = get_lux(in_ldr, out_ldr, LDRARRAYSIZE)/10.0; //read light level in lux
-    if (fabs(d.lastsentvalue-value_ldr)>=d.minchange){
-      _changed=true;
-    }
-    d.lastreadtime=millis();
-  }
-
-  if (_changed || millis() >= (d.lastsent+d.senddelaymax)) {
-    Serial.print("Sending LDR. reason=");
-    if (_changed) Serial.println("change"); else Serial.println("time");
-    checkESPStatus();
-
-    Homie.getLogger() << "light " << ": " << value_ldr << endl;
-    sensorNode.setProperty("light").send(String(value_ldr));
-    d.lastsentvalue=value_ldr;
-    
-    d.lastsent=millis();
-  }
-}
-#endif
-
-
 #ifdef SENSOR_MHZ19
 void loop_MHZ19()
 {
@@ -1045,7 +1007,7 @@ void loopHandler() {
   #endif
 
   #ifdef SENSOR_LDR
-    loop_LDR();
+    sensor_ldr.sensorloop();
   #endif
 
 
@@ -1093,43 +1055,6 @@ void checkESPStatus()
 }
 
 
-//////////////////////////////////////////////////////////////////////////////
-// Calculate lux based on rawADC reading from LDR returns value in lux/10
-//////////////////////////////////////////////////////////////////////////////
-//quelle: https://groups.google.com/forum/#!topic/souliss/1kMAltPB2ME[1-25]
-#ifdef SENSOR_LDR
-int get_lux(const unsigned int* _in, const unsigned int* _out, byte size)
-{
- 
-        // take care the value is within range
- // val = constrain(val, _in[0], _in[size-1]);
-
-
- unsigned int val = analogRead(LDR_PIN);
- #ifdef DEBUG   //DEBUG++++++++++++++++
-        Serial.print("LDR RAW=: ");
-        Serial.println(val);
- #endif
- 
- if (val <= _in[0]) return _out[0];
- if (val >= _in[size-1]) return _out[size-1];
-
-
- // search right interval
- byte pos = 1;  // _in[0] allready tested
- while(val > _in[pos]) pos++;
-
-
- // this will handle all exact "points" in the _in array
- if (val == _in[pos]) return _out[pos];
-
-
-
- // interpolate in the right segment for the rest
- return map(val, _in[pos-1], _in[pos], _out[pos-1], _out[pos]);
-}
-#endif
-
 
 #ifdef SENSOR_MHZ19
 byte mhz19_getCheckSum(byte* packet) {