diff --git a/examples/DIY_BASIC/DIY_BASIC.ino b/examples/DIY_BASIC/DIY_BASIC.ino
index 4c2a2a1..a80abfd 100644
--- a/examples/DIY_BASIC/DIY_BASIC.ino
+++ b/examples/DIY_BASIC/DIY_BASIC.ino
@@ -182,13 +182,15 @@ void showTextRectangle(String ln1, String ln2, boolean small) {
 void sendToServer() {
    if (currentMillis - previoussendToServer >= sendToServerInterval) {
      previoussendToServer += sendToServerInterval;
+
       String payload = "{\"wifi\":" + String(WiFi.RSSI())
-      + ", \"rco2\":" + String(Co2)
-      + ", \"pm02\":" + String(pm25)
+      + (Co2 < 0 ? "" : ", \"rco2\":" + String(Co2))
+      + (pm25 < 0 ? "" : ", \"pm02\":" + String(pm25))
       + ", \"atmp\":" + String(temp)
-      + ", \"rhum\":" + String(hum)
+      + (hum < 0 ? "" : ", \"rhum\":" + String(hum))
       + "}";
 
+
       if(WiFi.status()== WL_CONNECTED){
         Serial.println(payload);
         String POSTURL = APIROOT + "sensors/airgradient:" + String(ESP.getChipId(), HEX) + "/measures";
diff --git a/examples/DIY_BASIC_WITH_SGP30/DIY_BASIC_WITH_SGP30.ino b/examples/DIY_BASIC_WITH_SGP30/DIY_BASIC_WITH_SGP30.ino
deleted file mode 100644
index 2072455..0000000
--- a/examples/DIY_BASIC_WITH_SGP30/DIY_BASIC_WITH_SGP30.ino
+++ /dev/null
@@ -1,156 +0,0 @@
-/*
-This is the code for the AirGradient DIY BASIC Air Quality Sensor with an ESP8266 Microcontroller with Sensirion SGP30 instead of the SHT30. Due to instabilities on the I2C line running both SHT30 and SGP30 at the same time is not recommended. We recommend to switch to the DIY_PRO board and use the Sensirion SGP40.
-
-For build instructions please visit https://www.airgradient.com/open-airgradient/instructions/
-
-Instructions on using the TVOC sensor (SGP30) instead of the Temperature / Humidity sensor (SHT3x).
-
-https://www.airgradient.com/open-airgradient/instructions/tvoc-on-airgradient-diy-sensor/
-
-The codes needs the following libraries installed:
-"WifiManager by tzapu, tablatronix" tested with Version 2.0.3-alpha
-"ESP8266 and ESP32 OLED driver for SSD1306 displays by ThingPulse, Fabrice Weinberg" tested with Version 4.1.0
-"SGP30" by Rob Tillaart tested with Version 0.1.4
-
-Configuration:
-Set in the code below which sensor you are using and if you want to connect it to WiFi.
-
-If you have any questions please visit our forum at https://forum.airgradient.com/
-
-If you are a school or university contact us for a free trial on the AirGradient platform.
-https://www.airgradient.com/
-
-MIT License
-*/
-
-#include "SGP30.h"
-SGP30 SGP;
-
-#include <AirGradient.h>
-#include <WiFiManager.h>
-#include <ESP8266WiFi.h>
-#include <ESP8266HTTPClient.h>
-
-#include <Wire.h>
-#include "SSD1306Wire.h"
-
-AirGradient ag = AirGradient();
-
-SSD1306Wire display(0x3c, SDA, SCL);
-
-WiFiClient client;
-
-// set sensors that you do not use to false
-boolean hasPM=true;
-boolean hasCO2=true;
-boolean hasSHT=false;
-boolean hasTVOC=true;
-
-// set to true if you want to connect to wifi. The display will show values only when the sensor has wifi connection
-boolean connectWIFI=true;
-
-// change if you want to send the data to another server
-String APIROOT = "http://hw.airgradient.com/";
-
-void setup(){
-  Serial.begin(115200);
-
-  display.init();
-  display.flipScreenVertically();
-  showTextRectangle("Init", String(ESP.getChipId(),HEX),true);
-
-  if (hasTVOC) SGP.begin();
-  if (hasPM) ag.PMS_Init();
-  if (hasCO2) ag.CO2_Init();
-  if (hasSHT) ag.TMP_RH_Init(0x44);
-
-  if (connectWIFI) connectToWifi();
-  delay(2000);
-}
-
-void loop(){
-
-  if (hasTVOC) SGP.measure(false);
-
-    // create payload
-
-  String payload = "{\"wifi\":" + String(WiFi.RSSI()) + ",";
-
-  if (hasPM) {
-    int PM2 = ag.getPM2_Raw();
-    payload=payload+"\"pm02\":" + String(PM2);
-    showTextRectangle("PM2",String(PM2),false);
-    delay(3000);
-  }
-
-    if (hasTVOC) {
-    if (hasPM) payload=payload+",";
-    int TVOC = SGP.getTVOC();
-    payload=payload+"\"tvoc\":" + String(TVOC);
-    showTextRectangle("TVOC",String(TVOC),false);
-    delay(3000);
-  }
-
-  if (hasCO2) {
-    if (hasTVOC) payload=payload+",";
-    int CO2 = ag.getCO2_Raw();
-    payload=payload+"\"rco2\":" + String(CO2);
-    showTextRectangle("CO2",String(CO2),false);
-    delay(3000);
-  }
-
-  if (hasSHT) {
-    if (hasCO2 || hasPM) payload=payload+",";
-    TMP_RH result = ag.periodicFetchData();
-    payload=payload+"\"atmp\":" + String(result.t) +   ",\"rhum\":" + String(result.rh);
-    showTextRectangle(String(result.t),String(result.rh)+"%",false);
-    delay(3000);
-  }
-
-   payload=payload+"}";
-
-  // send payload
-  if (connectWIFI){
-  Serial.println(payload);
-  String POSTURL = APIROOT + "sensors/airgradient:" + String(ESP.getChipId(),HEX) + "/measures";
-  Serial.println(POSTURL);
-  WiFiClient client;
-  HTTPClient http;
-  http.begin(client, POSTURL);
-  http.addHeader("content-type", "application/json");
-  int httpCode = http.POST(payload);
-  String response = http.getString();
-  Serial.println(httpCode);
-  Serial.println(response);
-  http.end();
-  }
-}
-
-// DISPLAY
-void showTextRectangle(String ln1, String ln2, boolean small) {
-  display.clear();
-  display.setTextAlignment(TEXT_ALIGN_LEFT);
-  if (small) {
-    display.setFont(ArialMT_Plain_16);
-  } else {
-    display.setFont(ArialMT_Plain_24);
-  }
-  display.drawString(32, 16, ln1);
-  display.drawString(32, 36, ln2);
-  display.display();
-}
-
-// Wifi Manager
-void connectToWifi(){
-  WiFiManager wifiManager;
-  //WiFi.disconnect(); //to delete previous saved hotspot
-  String HOTSPOT = "AIRGRADIENT-"+String(ESP.getChipId(),HEX);
-  wifiManager.setTimeout(120);
-  if(!wifiManager.autoConnect((const char*)HOTSPOT.c_str())) {
-      Serial.println("failed to connect and hit timeout");
-      delay(3000);
-      ESP.restart();
-      delay(5000);
-  }
-
-}
diff --git a/examples/DIY_PRO/DIY_PRO.ino b/examples/DIY_PRO/DIY_PRO.ino
index 72a9aa0..ae6fb0c 100644
--- a/examples/DIY_PRO/DIY_PRO.ino
+++ b/examples/DIY_PRO/DIY_PRO.ino
@@ -10,7 +10,6 @@ Kits (including a pre-soldered version) are available: https://www.airgradient.c
 The codes needs the following libraries installed:
 “WifiManager by tzapu, tablatronix” tested with version 2.0.11-beta
 “U8g2” by oliver tested with version 2.32.15
-“SGP30” by Rob Tilaart tested with Version 0.1.5
 
 Configuration:
 Please set in the code below the configuration parameters.
@@ -30,12 +29,9 @@ MIT License
 #include <ESP8266WiFi.h>
 #include <ESP8266HTTPClient.h>
 #include <WiFiClient.h>
-
-#include "SGP30.h"
 #include <U8g2lib.h>
 
 AirGradient ag = AirGradient();
-SGP30 SGP;
 
 // Display bottom right
 U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
@@ -66,10 +62,6 @@ unsigned long previousOled = 0;
 const int sendToServerInterval = 10000;
 unsigned long previoussendToServer = 0;
 
-const int tvocInterval = 1000;
-unsigned long previousTVOC = 0;
-int TVOC = 0;
-
 const int co2Interval = 5000;
 unsigned long previousCo2 = 0;
 int Co2 = 0;
@@ -96,9 +88,6 @@ void setup()
 
   updateOLED2("Warming up the", "sensors.", "");
 
-  Serial.println(SGP.begin());
-  SGP.GenericReset();
-
   ag.CO2_Init();
   ag.PMS_Init();
   ag.TMP_RH_Init(0x44);
@@ -108,7 +97,6 @@ void setup()
 void loop()
 {
   currentMillis = millis();
-  updateTVOC();
   updateOLED();
   updateCo2();
   updatePm25();
@@ -116,16 +104,6 @@ void loop()
   sendToServer();
 }
 
-void updateTVOC()
-{
-    if (currentMillis - previousTVOC >= tvocInterval) {
-      previousTVOC += tvocInterval;
-      SGP.measure(true);
-      TVOC = SGP.getTVOC();
-      Serial.println(String(TVOC));
-    }
-}
-
 void updateCo2()
 {
     if (currentMillis - previousCo2 >= co2Interval) {
@@ -160,8 +138,8 @@ void updateOLED() {
      previousOled += oledInterval;
 
     String ln3;
-    String ln1 = "PM:" + String(pm25) +  " CO2:" + String(Co2);
-    String ln2 = "AQI:" + String(PM_TO_AQI_US(pm25)) + " TVOC:" + String(TVOC);
+    String ln1 = "PM:" + String(pm25) +  " AQI:" + String(PM_TO_AQI_US(pm25)) ;
+    String ln2 = "CO2:" + String(Co2);
 
       if (inF) {
         ln3 = "F:" + String((temp* 9 / 5) + 32) + " H:" + String(hum)+"%";
@@ -187,12 +165,12 @@ void updateOLED2(String ln1, String ln2, String ln3) {
 void sendToServer() {
    if (currentMillis - previoussendToServer >= sendToServerInterval) {
      previoussendToServer += sendToServerInterval;
+
       String payload = "{\"wifi\":" + String(WiFi.RSSI())
-      + ", \"rco2\":" + String(Co2)
-      + ", \"pm02\":" + String(pm25)
-      + ", \"tvoc\":" + String(TVOC)
+      + (Co2 < 0 ? "" : ", \"rco2\":" + String(Co2))
+      + (pm25 < 0 ? "" : ", \"pm02\":" + String(pm25))
       + ", \"atmp\":" + String(temp)
-      + ", \"rhum\":" + String(hum)
+      + (hum < 0 ? "" : ", \"rhum\":" + String(hum))
       + "}";
 
       if(WiFi.status()== WL_CONNECTED){
diff --git a/examples/DIY_PRO_WITH_SGP30/DIY_PRO_WITH_SGP30.ino b/examples/DIY_PRO_WITH_SGP30/DIY_PRO_WITH_SGP30.ino
new file mode 100644
index 0000000..b9fd09d
--- /dev/null
+++ b/examples/DIY_PRO_WITH_SGP30/DIY_PRO_WITH_SGP30.ino
@@ -0,0 +1,248 @@
+/*
+This is the code for the AirGradient DIY PRO Air Quality Sensor with an ESP8266 Microcontroller.
+
+It is a high quality sensor showing PM2.5, CO2, Temperature and Humidity on a small display and can send data over Wifi.
+
+Build Instructions: https://www.airgradient.com/open-airgradient/instructions/diy-pro/
+
+Kits (including a pre-soldered version) are available: https://www.airgradient.com/open-airgradient/kits/
+
+IMPORTANT: If you use SGP30 modules, you need to remove the Pull up resistors to make it work.
+See https://www.airgradient.com/open-airgradient/instructions/tvoc-on-airgradient-diy-sensor/
+
+If you want to use TVOC we strongly recommend you use the AirGradient SGP4x module available in our online shop.
+
+The codes needs the following libraries installed:
+“WifiManager by tzapu, tablatronix” tested with version 2.0.11-beta
+“U8g2” by oliver tested with version 2.32.15
+“SGP30” by Rob Tilaart tested with Version 0.1.5
+
+Configuration:
+Please set in the code below the configuration parameters.
+
+If you have any questions please visit our forum at https://forum.airgradient.com/
+
+If you are a school or university contact us for a free trial on the AirGradient platform.
+https://www.airgradient.com/
+
+MIT License
+
+*/
+
+
+#include <AirGradient.h>
+#include <WiFiManager.h>
+#include <ESP8266WiFi.h>
+#include <ESP8266HTTPClient.h>
+#include <WiFiClient.h>
+
+#include "SGP30.h"
+#include <U8g2lib.h>
+
+AirGradient ag = AirGradient();
+SGP30 SGP;
+
+// Display bottom right
+U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
+
+// Replace above if you have display on top left
+//U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R2, /* reset=*/ U8X8_PIN_NONE);
+
+
+// CONFIGURATION START
+
+//set to the endpoint you would like to use
+String APIROOT = "http://hw.airgradient.com/";
+
+// set to true to switch from Celcius to Fahrenheit
+boolean inF = false;
+
+// set to true if you want to connect to wifi. You have 60 seconds to connect. Then it will go into an offline mode.
+boolean connectWIFI=true;
+
+// CONFIGURATION END
+
+
+unsigned long currentMillis = 0;
+
+const int oledInterval = 5000;
+unsigned long previousOled = 0;
+
+const int sendToServerInterval = 10000;
+unsigned long previoussendToServer = 0;
+
+const int tvocInterval = 1000;
+unsigned long previousTVOC = 0;
+int TVOC = 0;
+
+const int co2Interval = 5000;
+unsigned long previousCo2 = 0;
+int Co2 = 0;
+
+const int pm25Interval = 5000;
+unsigned long previousPm25 = 0;
+int pm25 = 0;
+
+const int tempHumInterval = 2500;
+unsigned long previousTempHum = 0;
+float temp = 0;
+int hum = 0;
+
+void setup()
+{
+  Serial.begin(115200);
+
+  u8g2.begin();
+  updateOLED();
+
+    if (connectWIFI) {
+    connectToWifi();
+  }
+
+  updateOLED2("Warming up the", "sensors.", "");
+
+  Serial.println(SGP.begin());
+  SGP.GenericReset();
+
+  ag.CO2_Init();
+  ag.PMS_Init();
+  ag.TMP_RH_Init(0x44);
+}
+
+
+void loop()
+{
+  currentMillis = millis();
+  updateTVOC();
+  updateOLED();
+  updateCo2();
+  updatePm25();
+  updateTempHum();
+  sendToServer();
+}
+
+void updateTVOC()
+{
+    if (currentMillis - previousTVOC >= tvocInterval) {
+      previousTVOC += tvocInterval;
+      SGP.measure(true);
+      TVOC = SGP.getTVOC();
+      Serial.println(String(TVOC));
+    }
+}
+
+void updateCo2()
+{
+    if (currentMillis - previousCo2 >= co2Interval) {
+      previousCo2 += co2Interval;
+      Co2 = ag.getCO2_Raw();
+      Serial.println(String(Co2));
+    }
+}
+
+void updatePm25()
+{
+    if (currentMillis - previousPm25 >= pm25Interval) {
+      previousPm25 += pm25Interval;
+      pm25 = ag.getPM2_Raw();
+      Serial.println(String(pm25));
+    }
+}
+
+void updateTempHum()
+{
+    if (currentMillis - previousTempHum >= tempHumInterval) {
+      previousTempHum += tempHumInterval;
+      TMP_RH result = ag.periodicFetchData();
+      temp = result.t;
+      hum = result.rh;
+      Serial.println(String(temp));
+    }
+}
+
+void updateOLED() {
+   if (currentMillis - previousOled >= oledInterval) {
+     previousOled += oledInterval;
+
+    String ln3;
+    String ln1 = "PM:" + String(pm25) +  " CO2:" + String(Co2);
+    String ln2 = "AQI:" + String(PM_TO_AQI_US(pm25)) + " TVOC:" + String(TVOC);
+
+      if (inF) {
+        ln3 = "F:" + String((temp* 9 / 5) + 32) + " H:" + String(hum)+"%";
+        } else {
+        ln3 = "C:" + String(temp) + " H:" + String(hum)+"%";
+       }
+     updateOLED2(ln1, ln2, ln3);
+   }
+}
+
+void updateOLED2(String ln1, String ln2, String ln3) {
+      char buf[9];
+          u8g2.firstPage();
+          u8g2.firstPage();
+          do {
+          u8g2.setFont(u8g2_font_t0_16_tf);
+          u8g2.drawStr(1, 10, String(ln1).c_str());
+          u8g2.drawStr(1, 30, String(ln2).c_str());
+          u8g2.drawStr(1, 50, String(ln3).c_str());
+            } while ( u8g2.nextPage() );
+}
+
+void sendToServer() {
+   if (currentMillis - previoussendToServer >= sendToServerInterval) {
+     previoussendToServer += sendToServerInterval;
+
+      String payload = "{\"wifi\":" + String(WiFi.RSSI())
+      + (Co2 < 0 ? "" : ", \"rco2\":" + String(Co2))
+      + (pm25 < 0 ? "" : ", \"pm02\":" + String(pm25))
+      + (TVOC < 0 ? "" : ", \"tvoc\":" + String(TVOC))
+      + ", \"atmp\":" + String(temp)
+      + (hum < 0 ? "" : ", \"rhum\":" + String(hum))
+      + "}";
+
+      if(WiFi.status()== WL_CONNECTED){
+        Serial.println(payload);
+        String POSTURL = APIROOT + "sensors/airgradient:" + String(ESP.getChipId(), HEX) + "/measures";
+        Serial.println(POSTURL);
+        WiFiClient client;
+        HTTPClient http;
+        http.begin(client, POSTURL);
+        http.addHeader("content-type", "application/json");
+        int httpCode = http.POST(payload);
+        String response = http.getString();
+        Serial.println(httpCode);
+        Serial.println(response);
+        http.end();
+      }
+      else {
+        Serial.println("WiFi Disconnected");
+      }
+   }
+}
+
+// Wifi Manager
+ void connectToWifi() {
+   WiFiManager wifiManager;
+   //WiFi.disconnect(); //to delete previous saved hotspot
+   String HOTSPOT = "AG-" + String(ESP.getChipId(), HEX);
+   updateOLED2("60s to connect", "to Wifi Hotspot", HOTSPOT);
+   wifiManager.setTimeout(60);
+   if (!wifiManager.autoConnect((const char * ) HOTSPOT.c_str())) {
+     updateOLED2("booting into", "offline mode", "");
+     Serial.println("failed to connect and hit timeout");
+     delay(6000);
+   }
+}
+
+// Calculate PM2.5 US AQI
+int PM_TO_AQI_US(int pm02) {
+  if (pm02 <= 12.0) return ((50 - 0) / (12.0 - .0) * (pm02 - .0) + 0);
+  else if (pm02 <= 35.4) return ((100 - 50) / (35.4 - 12.0) * (pm02 - 12.0) + 50);
+  else if (pm02 <= 55.4) return ((150 - 100) / (55.4 - 35.4) * (pm02 - 35.4) + 100);
+  else if (pm02 <= 150.4) return ((200 - 150) / (150.4 - 55.4) * (pm02 - 55.4) + 150);
+  else if (pm02 <= 250.4) return ((300 - 200) / (250.4 - 150.4) * (pm02 - 150.4) + 200);
+  else if (pm02 <= 350.4) return ((400 - 300) / (350.4 - 250.4) * (pm02 - 250.4) + 300);
+  else if (pm02 <= 500.4) return ((500 - 400) / (500.4 - 350.4) * (pm02 - 350.4) + 400);
+  else return 500;
+};
diff --git a/examples/DIY_PRO_WITH_SGP40/DIY_PRO_WITH_SGP40.ino b/examples/DIY_PRO_WITH_SGP40/DIY_PRO_WITH_SGP40.ino
index b9b4c51..7a12264 100644
--- a/examples/DIY_PRO_WITH_SGP40/DIY_PRO_WITH_SGP40.ino
+++ b/examples/DIY_PRO_WITH_SGP40/DIY_PRO_WITH_SGP40.ino
@@ -185,11 +185,11 @@ void sendToServer() {
    if (currentMillis - previoussendToServer >= sendToServerInterval) {
      previoussendToServer += sendToServerInterval;
       String payload = "{\"wifi\":" + String(WiFi.RSSI())
-      + ", \"rco2\":" + String(Co2)
-      + ", \"pm02\":" + String(pm25)
-      + ", \"tvoc\":" + String(TVOC)
+      + (Co2 < 0 ? "" : ", \"rco2\":" + String(Co2))
+      + (pm25 < 0 ? "" : ", \"pm02\":" + String(pm25))
+      + (TVOC < 0 ? "" : ", \"tvoc_index\":" + String(TVOC))
       + ", \"atmp\":" + String(temp)
-      + ", \"rhum\":" + String(hum)
+      + (hum < 0 ? "" : ", \"rhum\":" + String(hum))
       + "}";
 
       if(WiFi.status()== WL_CONNECTED){
diff --git a/library.properties b/library.properties
index e60aafd..1ba9d10 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=AirGradient Air Quality Sensor
-version=2.1.0
+version=2.2.0
 author=AirGradient <support@airgradient.com>
 maintainer=AirGradient <support@airgradient.com>
 sentence=ESP8266 library for an air quality sensor featuring PM2.5, CO2, Temperature, TVOC and Humidity with OLED display.