diff --git a/include/cyclic.h b/include/cyclic.h
index 4b402360..ccadbb65 100644
--- a/include/cyclic.h
+++ b/include/cyclic.h
@@ -18,6 +18,15 @@
 #include "display.h"
 #endif
 
+#if (HAS_SDS011)
+#include "sds011read.h"
+#endif
+
+#if (HAS_SDCARD)
+#include "sdcard.h"
+#endif
+
+
 extern Ticker housekeeper;
 
 void housekeeping(void);
diff --git a/include/payload.h b/include/payload.h
index b41bb113..719d59ec 100644
--- a/include/payload.h
+++ b/include/payload.h
@@ -3,6 +3,10 @@
 
 #include "paxcounter.conf"
 
+#if (HAS_SDS011)
+#include "sds011read.h"
+#endif
+
 // MyDevices CayenneLPP 1.0 channels for Synamic sensor payload format
 // all payload goes out on LoRa FPort 1
 #if (PAYLOAD_ENCODER == 3)
@@ -55,6 +59,10 @@ public:
   void addButton(uint8_t value);
   void addSensor(uint8_t[]);
   void addTime(time_t value);
+  void addPM10(float value);
+  void addPM25(float value);
+private:
+  void addChars( char* string, int len);
 
 #if (PAYLOAD_ENCODER == 1) // format plain
 
@@ -95,4 +103,4 @@ private:
 
 extern PayloadConvert payload;
 
-#endif // _PAYLOAD_H_
\ No newline at end of file
+#endif // _PAYLOAD_H_
diff --git a/include/sdcard.h b/include/sdcard.h
index 051baa19..99e784cb 100644
--- a/include/sdcard.h
+++ b/include/sdcard.h
@@ -10,7 +10,7 @@
 #define SDCARD_FILE_NAME       "paxcount.%02d"
 #define SDCARD_FILE_HEADER     "date, time, wifi, bluet"
 
-bool sdcardInit( void );
+bool sdcard_init( void );
 void sdcardWriteData( uint16_t, uint16_t);
 
-#endif
\ No newline at end of file
+#endif
diff --git a/include/sds011read.h b/include/sds011read.h
new file mode 100644
index 00000000..8c573c0d
--- /dev/null
+++ b/include/sds011read.h
@@ -0,0 +1,13 @@
+#ifndef _SDS011READ_H
+#define _SDS011READ_H
+
+#include <SDS011.h>
+
+#define SDCARD_FILE_HEADER_SDS011     ", PM10,PM25"
+
+bool sds011_init();
+void sds011_loop();
+void sds011_sleep(void);
+void sds011_wakeup(void);
+
+#endif // _SDS011READ_H
diff --git a/platformio.ini b/platformio.ini
index df7e17c2..704ebdc7 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -73,6 +73,8 @@ lib_deps_sensors =
     Adafruit BME280 Library@>=2.0.0
     Adafruit BMP085 Library@>=1.0.1
     BSEC Software Library@1.5.1474
+    ;SDS011 sensor Library
+    https://github.com/ricki-z/SDS011.git#33fd8b6
 lib_deps_basic =
     ArduinoJson@^5.13.1
     76@>=1.2.4 ; #76 Timezone by Jack Christensen
diff --git a/src/cyclic.cpp b/src/cyclic.cpp
index 89f8e3e2..b0223381 100644
--- a/src/cyclic.cpp
+++ b/src/cyclic.cpp
@@ -9,6 +9,10 @@ static const char TAG[] = __FILE__;
 
 Ticker housekeeper;
 
+#if (HAS_SDS011)
+extern boolean isSDS011Active;
+#endif
+
 void housekeeping() {
   xTaskNotifyFromISR(irqHandlerTask, CYCLIC_IRQ, eSetBits, NULL);
 }
@@ -18,7 +22,6 @@ void doHousekeeping() {
 
   // update uptime counter
   uptime();
-
   // check if update mode trigger switch was set
   if (RTC_runmode == RUNMODE_UPDATE) {
     // check battery status if we can before doing ota
@@ -112,6 +115,17 @@ void doHousekeeping() {
   }
 #endif
 
+#if (HAS_SDS011)
+    if ( isSDS011Active ) {
+        ESP_LOGD(TAG, "SDS011: go to sleep");
+        sds011_loop();
+    }
+    else {
+        ESP_LOGD(TAG, "SDS011: wakeup");
+        sds011_wakeup();
+    }
+#endif
+
 } // doHousekeeping()
 
 // uptime counter 64bit to prevent millis() rollover after 49 days
@@ -143,4 +157,4 @@ void reset_counters() {
 #endif
 
 #endif
-}
\ No newline at end of file
+}
diff --git a/src/hal/generic.h b/src/hal/generic.h
index 5d56e591..fa1d14c7 100644
--- a/src/hal/generic.h
+++ b/src/hal/generic.h
@@ -100,4 +100,4 @@
 #define MCP_24AA02E64_I2C_ADDRESS 0x50 // I2C address for the 24AA02E64 
 #define MCP_24AA02E64_MAC_ADDRESS 0xF8 // Memory adress of unique deveui 64 bits
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/hal/ttgov21new.h b/src/hal/ttgov21new.h
index 90f93c7a..9fa665f2 100644
--- a/src/hal/ttgov21new.h
+++ b/src/hal/ttgov21new.h
@@ -12,6 +12,12 @@
 // This settings are for boards labeled v1.6 on pcb, NOT for v1.5 or older
 */
 
+// SDS011 dust sensor settings
+#define HAS_SDS011 1 // use SDS011
+// used pins on the ESP-side:
+#define ESP_PIN_TX 19     // connect to RX on the SDS011
+#define ESP_PIN_RX 23     // connect to TX on the SDS011
+
 #define HAS_LORA 1       // comment out if device shall not send data via LoRa
 #define CFG_sx1276_radio 1 // HPD13A LoRa SoC
 
@@ -48,4 +54,4 @@
 #define LORA_IO1  (33)
 #define LORA_IO2  (32)
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/main.cpp b/src/main.cpp
index 5e761b0e..c8f3af3d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -324,10 +324,16 @@ void setup() {
 #endif
 
 #ifdef HAS_SDCARD
-  if (sdcardInit())
+  if (sdcard_init())
     strcat_P(features, " SD");
 #endif
 
+#if (HAS_SDS011)
+    ESP_LOGI(TAG, "init fine-dust-sensor");
+    if ( sds011_init() )
+        strcat_P(features, " SDS");
+#endif
+
 #if (VENDORFILTER)
   strcat_P(features, " FILTER");
 #endif
diff --git a/src/payload.cpp b/src/payload.cpp
index 323e402b..57428234 100644
--- a/src/payload.cpp
+++ b/src/payload.cpp
@@ -489,5 +489,41 @@ void PayloadConvert::addTime(time_t value) {
   buffer[cursor++] = (byte)((tx_period & 0x000000FF));
 #endif
 }
+#endif // PAYLOAD_ENCODER
 
-#endif
\ No newline at end of file
+void PayloadConvert::addPM10( float value) {
+#if (HAS_SDS011)
+#if (PAYLOAD_ENCODER == 1)   // plain
+    char tempBuffer[10+1];
+    sprintf( tempBuffer, ",%5.1f", value);
+    addChars(tempBuffer, strlen(tempBuffer));
+#elif (PAYLOAD_ENCODER == 2 ) // packed
+    writeUint16( (uint16_t) (value*10) );
+#elif (PAYLOAD_ENCODER == 3 ) // Cayenne LPP dynamic
+#error not implemented yet
+#elif (PAYLOAD_ENCODER == 4 ) // Cayenne LPP packed
+#error not implemented yet
+#endif
+#endif // HAS_SDS011
+}
+
+void PayloadConvert::addPM25( float value) {
+#if (HAS_SDS011)
+#if (PAYLOAD_ENCODER == 1)   // plain
+    char tempBuffer[10+1];
+    sprintf( tempBuffer, ",%5.1f", value);
+    addChars(tempBuffer, strlen(tempBuffer));
+#elif (PAYLOAD_ENCODER == 2 ) // packed
+    writeUint16( (uint16_t) (value*10) );
+#elif (PAYLOAD_ENCODER == 3 ) // Cayenne LPP dynamic
+#error not implemented yet
+#elif (PAYLOAD_ENCODER == 4 ) // Cayenne LPP packed
+#error not implemented yet
+#endif
+#endif // HAS_SDS011
+}
+
+void PayloadConvert::addChars( char * string, int len) {
+  for (int i=0; i < len; i++)
+      addByte(string[i]);
+}
diff --git a/src/sdcard.cpp b/src/sdcard.cpp
index 0633151f..002cfdf8 100644
--- a/src/sdcard.cpp
+++ b/src/sdcard.cpp
@@ -6,6 +6,12 @@
 static const char TAG[] = __FILE__;
 
 #include "sdcard.h"
+#if (HAS_SDS011)
+#include <sds011read.h>
+// the results of the sensor:
+extern float pm25;              
+extern float pm10;
+#endif
 
 static bool useSDCard;
 
@@ -13,11 +19,13 @@ static void createFile(void);
 
 File fileSDCard;
 
-bool sdcardInit() {
+bool sdcard_init() {
   ESP_LOGD(TAG, "looking for SD-card...");
   useSDCard = SD.begin(SDCARD_CS, SDCARD_MOSI, SDCARD_MISO, SDCARD_SCLK);
   if (useSDCard)
     createFile();
+  else
+      ESP_LOGD(TAG,"SD-card not found");
   return useSDCard;
 }
 
@@ -35,7 +43,12 @@ void sdcardWriteData(uint16_t noWifi, uint16_t noBle) {
   sprintf(tempBuffer, "%02d:%02d:%02d,", hour(t), minute(t), second(t));
   fileSDCard.print(tempBuffer);
   sprintf(tempBuffer, "%d,%d", noWifi, noBle);
-  fileSDCard.println(tempBuffer);
+  fileSDCard.print( tempBuffer);
+#if (HAS_SDS011)
+    sprintf(tempBuffer, ",%5.1f,%4.1f", pm10, pm25);
+    fileSDCard.print( tempBuffer);
+#endif
+  fileSDCard.println( );
 
   if (++counterWrites > 2) {
     // force writing to SD-card
@@ -58,8 +71,12 @@ void createFile(void) {
       ESP_LOGD(TAG, "SD: file does not exist: opening");
       fileSDCard = SD.open(bufferFilename, FILE_WRITE);
       if (fileSDCard) {
-        ESP_LOGD(TAG, "SD: name opended: <%s>", bufferFilename);
-        fileSDCard.println(SDCARD_FILE_HEADER);
+        ESP_LOGD(TAG, "SD: name opened: <%s>", bufferFilename);
+        fileSDCard.print( SDCARD_FILE_HEADER );
+#if (HAS_SDS011)
+        fileSDCard.print( SDCARD_FILE_HEADER_SDS011 );
+#endif
+        fileSDCard.println();
         useSDCard = true;
         break;
       }
@@ -68,4 +85,4 @@ void createFile(void) {
   return;
 }
 
-#endif // (HAS_SDCARD)
\ No newline at end of file
+#endif // (HAS_SDCARD)
diff --git a/src/sds011read.cpp b/src/sds011read.cpp
new file mode 100644
index 00000000..f280fbe6
--- /dev/null
+++ b/src/sds011read.cpp
@@ -0,0 +1,58 @@
+// routines for fetching data from the SDS011-sensor
+
+// Local logging tag
+static const char TAG[] = __FILE__;
+
+#include "sds011read.h"
+
+#if (HAS_IF482)
+#error cannot use IF482 together with SDS011 (both use UART#2)
+#endif
+// UART(2) is unused in this project
+static HardwareSerial sdsSerial(2); // so we use it here
+static SDS011 sdsSensor;            // fine dust sensor
+
+// the results of the sensor:
+float pm25;
+float pm10;
+boolean isSDS011Active;
+
+// init
+bool sds011_init() {
+  pm25 = pm10 = 0.0;
+#if (HAS_SDS011)  
+  sdsSensor.begin (&sdsSerial,  ESP_PIN_RX, ESP_PIN_TX);
+#endif  
+  sds011_sleep();        // we do sleep/wakup by ourselves
+  return true;
+}
+
+// reading data:
+void sds011_loop() {
+  if (isSDS011Active) {
+    int sdsErrorCode = sdsSensor.read(&pm25, &pm10);
+    if (sdsErrorCode) {
+      pm25 = pm10 = 0.0;
+      ESP_LOGI(TAG, "SDS011 error: %d", sdsErrorCode);
+    } else {
+      ESP_LOGI(TAG, "fine-dust-values: %5.1f,%4.1f", pm10, pm25);
+    }
+    sds011_sleep();
+  }
+  return;
+}
+
+// putting the SDS-sensor to sleep
+void sds011_sleep(void) {
+  sdsSensor.sleep();
+  isSDS011Active = false;
+}
+
+// start the SDS-sensor
+// needs 30 seconds for warming up
+void sds011_wakeup() {
+  if (!isSDS011Active) {
+    sdsSensor.wakeup();
+    isSDS011Active = true;
+  }
+}
diff --git a/src/senddata.cpp b/src/senddata.cpp
index f4f6b085..f5b867f6 100644
--- a/src/senddata.cpp
+++ b/src/senddata.cpp
@@ -3,6 +3,11 @@
 
 Ticker sendcycler;
 
+#if (HAS_SDS011)
+extern float pm10;
+extern float pm25;
+#endif
+
 void sendcycle() {
   xTaskNotifyFromISR(irqHandlerTask, SENDCYCLE_IRQ, eSetBits, NULL);
 }
@@ -94,6 +99,10 @@ void sendData() {
         payload.addCount(macs_wifi, MAC_SNIFF_WIFI);
       if (cfg.blescan)
         payload.addCount(macs_ble, MAC_SNIFF_BLE);
+#endif
+#if (HAS_SDS011)
+      payload.addPM10(pm10);
+      payload.addPM25(pm25);
 #endif
       SendPayload(COUNTERPORT, prio_normal);
       // clear counter if not in cumulative counter mode
@@ -172,4 +181,4 @@ void flushQueues() {
 #ifdef HAS_SPI
   spi_queuereset();
 #endif
-}
\ No newline at end of file
+}
diff --git a/src/timekeeper.cpp b/src/timekeeper.cpp
index 85f62864..f95a97ab 100644
--- a/src/timekeeper.cpp
+++ b/src/timekeeper.cpp
@@ -16,6 +16,9 @@ static const char TAG[] = __FILE__;
 const char timeSetSymbols[] = {'G', 'R', 'L', '?'};
 
 #ifdef HAS_IF482
+#if (HAS_SDS011)
+#error cannot use IF482 together with SDS011 (both use UART#2)
+#endif
 HardwareSerial IF482(2); // use UART #2 (#1 may be in use for serial GPS)
 #endif