diff --git a/examples/PRO_V9/PRO_V9.ino b/examples/PRO_V9/PRO_V9.ino
index e032182..c0b99b5 100644
--- a/examples/PRO_V9/PRO_V9.ino
+++ b/examples/PRO_V9/PRO_V9.ino
@@ -1,16 +1,25 @@
 #include "PMS.h"
+
 #include <HardwareSerial.h>
+
 #include <Wire.h>
+
 #include "s8_uart.h"
+
 #include <HTTPClient.h>
+
 #include <WiFiManager.h>
+
 #include <Adafruit_NeoPixel.h>
 
 #include <EEPROM.h>
+
 #include "SHTSensor.h"
 
 #include <SensirionI2CSgp41.h>
+
 #include <NOxGasIndexAlgorithm.h>
+
 #include <VOCGasIndexAlgorithm.h>
 
 #include <U8g2lib.h>
@@ -32,7 +41,7 @@ PMS pms1(Serial0);
 
 PMS::DATA data1;
 
-S8_UART* sensor_S8;
+S8_UART * sensor_S8;
 S8_sensor sensor;
 
 // time in seconds needed for NOx conditioning
@@ -56,12 +65,14 @@ boolean inUSAQI = false;
 // Display Position
 boolean displayTop = true;
 
+// use RGB LED Bar
+boolean useRGBledBar = true;
+
 // 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;
+boolean connectWIFI = true;
 
 int loopCount = 0;
 
-
 unsigned long currentMillis = 0;
 
 const int oledInterval = 5000;
@@ -91,34 +102,26 @@ unsigned long previousTempHum = 0;
 float temp = 0;
 int hum = 0;
 
-int buttonConfig=0;
+int buttonConfig = 0;
 int lastState = LOW;
 int currentState;
-unsigned long pressedTime  = 0;
+unsigned long pressedTime = 0;
 unsigned long releasedTime = 0;
 
 void setup() {
-    if (DEBUG) {
-      Serial.begin(115200);
-      // see https://github.com/espressif/arduino-esp32/issues/6983
-      Serial.setTxTimeoutMs(0);   // <<<====== solves the delay issue
-    }
-
-    Wire.begin(I2C_SDA, I2C_SCL);
-    pixels.begin();
-
-    pixels.clear(); 
-  for(int i=0; i<11; i++) {
-    pixels.setPixelColor(i, pixels.Color(255, 255, 255));
-    pixels.show(); 
-    delay(100);
+  if (DEBUG) {
+    Serial.begin(115200);
+    // see https://github.com/espressif/arduino-esp32/issues/6983
+    Serial.setTxTimeoutMs(0); // <<<====== solves the delay issue
   }
-   
-    Serial1.begin(9600, SERIAL_8N1, 0, 1);
-    Serial0.begin(9600);
 
-    Serial.println("Hello");
-    u8g2.begin();
+  Wire.begin(I2C_SDA, I2C_SCL);
+  pixels.begin();
+  pixels.clear();
+
+  Serial1.begin(9600, SERIAL_8N1, 0, 1);
+  Serial0.begin(9600);
+  u8g2.begin();
 
   updateOLED2("Warming Up", "Serial Number:", String(getNormalizedMac()));
   sgp41.begin(Wire);
@@ -126,38 +129,27 @@ void setup() {
   sht.init(Wire);
   sht.setAccuracy(SHTSensor::SHT_ACCURACY_MEDIUM);
 
-  
-    sensor_S8 = new S8_UART(Serial1);
+  //init Watchdog
+  pinMode(2, OUTPUT);
+  digitalWrite(2, LOW);
 
-    // Check if S8 is available
-    sensor_S8->get_firmware_version(sensor.firm_version);
-    int len = strlen(sensor.firm_version);
-    if (len == 0) {
-        debugln("SenseAir S8 CO2 sensor not found!");
-    }
-
-//     Show basic S8 sensor info
-//    debugln(">>> SenseAir S8 NDIR CO2 sensor <<<");
-//    sensor.sensor_id = sensor_S8->get_sensor_ID();
+  sensor_S8 = new S8_UART(Serial1);
 
   EEPROM.begin(512);
   delay(500);
 
+  // push button
+  pinMode(9, INPUT_PULLUP);
 
-    // push button
-    pinMode(9, INPUT_PULLUP);
-
-buttonConfig = String(EEPROM.read(addr)).toInt();
-  if (buttonConfig>3) buttonConfig=0;
+  buttonConfig = String(EEPROM.read(addr)).toInt();
+  if (buttonConfig > 3) buttonConfig = 0;
   delay(400);
   setConfig();
-  Serial.println("buttonConfig: "+String(buttonConfig));
-   updateOLED2("Press Button", "Now for", "Config Menu");
-    delay(2000);
- // pinMode(D7, INPUT_PULLUP);
+  Serial.println("buttonConfig: " + String(buttonConfig));
+  updateOLED2("Press Button", "Now for", "Config Menu");
+  delay(2000);
   currentState = digitalRead(9);
-  if (currentState == LOW)
-  {
+  if (currentState == LOW) {
     updateOLED2("Entering", "Config Menu", "");
     delay(3000);
     lastState = HIGH;
@@ -165,14 +157,13 @@ buttonConfig = String(EEPROM.read(addr)).toInt();
     inConf();
   }
 
-    countdown(3);
+  countdown(3);
 
-  if (connectWIFI)
-  {
-     connectToWifi();
+  if (connectWIFI) {
+    connectToWifi();
   }
-    sendPing();
-    updateOLED2("Warming Up", "Serial Number:", String(getNormalizedMac()));
+  sendPing();
+  updateOLED2("Warming Up", "Serial Number:", String(getNormalizedMac()));
 }
 
 void loop() {
@@ -185,135 +176,129 @@ void loop() {
   sendToServer();
 }
 
-void updateTVOC()
-{
- uint16_t error;
-    char errorMessage[256];
-    uint16_t defaultRh = 0x8000;
-    uint16_t defaultT = 0x6666;
-    uint16_t srawVoc = 0;
-    uint16_t srawNox = 0;
-    uint16_t defaultCompenstaionRh = 0x8000;  // in ticks as defined by SGP41
-    uint16_t defaultCompenstaionT = 0x6666;   // in ticks as defined by SGP41
-    uint16_t compensationRh = 0;              // in ticks as defined by SGP41
-    uint16_t compensationT = 0;               // in ticks as defined by SGP41
+void updateTVOC() {
+  uint16_t error;
+  char errorMessage[256];
+  uint16_t defaultRh = 0x8000;
+  uint16_t defaultT = 0x6666;
+  uint16_t srawVoc = 0;
+  uint16_t srawNox = 0;
+  uint16_t defaultCompenstaionRh = 0x8000; // in ticks as defined by SGP41
+  uint16_t defaultCompenstaionT = 0x6666; // in ticks as defined by SGP41
+  uint16_t compensationRh = 0; // in ticks as defined by SGP41
+  uint16_t compensationT = 0; // in ticks as defined by SGP41
 
-    delay(1000);
+  delay(1000);
 
-    compensationT = static_cast<uint16_t>((temp + 45) * 65535 / 175);
-    compensationRh = static_cast<uint16_t>(hum * 65535 / 100);
+  compensationT = static_cast < uint16_t > ((temp + 45) * 65535 / 175);
+  compensationRh = static_cast < uint16_t > (hum * 65535 / 100);
 
-    if (conditioning_s > 0) {
-        error = sgp41.executeConditioning(compensationRh, compensationT, srawVoc);
-        conditioning_s--;
-    } else {
-        error = sgp41.measureRawSignals(compensationRh, compensationT, srawVoc,
-                                        srawNox);
-    }
+  if (conditioning_s > 0) {
+    error = sgp41.executeConditioning(compensationRh, compensationT, srawVoc);
+    conditioning_s--;
+  } else {
+    error = sgp41.measureRawSignals(compensationRh, compensationT, srawVoc,
+      srawNox);
+  }
 
-    if (currentMillis - previousTVOC >= tvocInterval) {
-      previousTVOC += tvocInterval;
-      TVOC = voc_algorithm.process(srawVoc);
-      NOX = nox_algorithm.process(srawNox);
-      Serial.println(String(TVOC));
-    }
+  if (currentMillis - previousTVOC >= tvocInterval) {
+    previousTVOC += tvocInterval;
+    TVOC = voc_algorithm.process(srawVoc);
+    NOX = nox_algorithm.process(srawNox);
+    Serial.println(String(TVOC));
+  }
 }
 
-void updateCo2()
-{
-    if (currentMillis - previousCo2 >= co2Interval) {
-      previousCo2 += co2Interval;
-      Co2 = sensor_S8->get_co2();
-      Serial.println(String(Co2));
-    }
+void updateCo2() {
+  if (currentMillis - previousCo2 >= co2Interval) {
+    previousCo2 += co2Interval;
+    Co2 = sensor_S8 -> get_co2();
+    Serial.println(String(Co2));
+    setRGBledCO2color(Co2);
+  }
 }
 
-void updatePm()
-{
-    if (currentMillis - previousPm >= pmInterval) {
-      previousPm += pmInterval;
-      if (pms1.readUntil(data1, 2000)) {
+void updatePm() {
+  if (currentMillis - previousPm >= pmInterval) {
+    previousPm += pmInterval;
+    if (pms1.readUntil(data1, 2000)) {
       pm01 = data1.PM_AE_UG_1_0;
       pm25 = data1.PM_AE_UG_2_5;
       pm10 = data1.PM_AE_UG_10_0;
       pm03PCount = data1.PM_RAW_0_3;
-      }
     }
+  }
 }
 
-void updateTempHum()
-{
-    if (currentMillis - previousTempHum >= tempHumInterval) {
-      previousTempHum += tempHumInterval;
+void updateTempHum() {
+  if (currentMillis - previousTempHum >= tempHumInterval) {
+    previousTempHum += tempHumInterval;
 
-      if (sht.readSample()) {
+    if (sht.readSample()) {
       temp = sht.getTemperature();
       hum = sht.getHumidity();
-        } else {
-            Serial.print("Error in readSample()\n");
-                }
-     }
+    } else {
+      Serial.print("Error in readSample()\n");
+    }
+  }
 }
 
 void updateOLED() {
-   if (currentMillis - previousOled >= oledInterval) {
-     previousOled += oledInterval;
+  if (currentMillis - previousOled >= oledInterval) {
+    previousOled += oledInterval;
 
     String ln3;
     String ln1;
 
     if (inUSAQI) {
-      ln1 = "AQI:" + String(PM_TO_AQI_US(pm25)) +  " CO2:" + String(Co2);
+      ln1 = "AQI:" + String(PM_TO_AQI_US(pm25)) + " CO2:" + String(Co2);
     } else {
-      ln1 = "PM:" + String(pm25) +  " CO2:" + String(Co2);
+      ln1 = "PM:" + String(pm25) + " CO2:" + String(Co2);
     }
 
-     String ln2 = "TVOC:" + String(TVOC) + " NOX:" + String(NOX);
+    String ln2 = "TVOC:" + String(TVOC) + " NOX:" + String(NOX);
 
-      if (inF) {
-        ln3 = "F:" + String((temp* 9 / 5) + 32) + " H:" + String(hum)+"%";
-        } else {
-        ln3 = "C:" + String(temp) + " H:" + String(hum)+"%";
-       }
-     updateOLED2(ln1, ln2, ln3);
-   }
+    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 inConf(){
+void inConf() {
   setConfig();
   currentState = digitalRead(9);
 
-  if (currentState){
+  if (currentState) {
     Serial.println("currentState: high");
   } else {
     Serial.println("currentState: low");
   }
 
-  if(lastState == HIGH && currentState == LOW) {
+  if (lastState == HIGH && currentState == LOW) {
     pressedTime = millis();
-  }
-
-  else if(lastState == LOW && currentState == HIGH) {
+  } else if (lastState == LOW && currentState == HIGH) {
     releasedTime = millis();
     long pressDuration = releasedTime - pressedTime;
-    if( pressDuration < 1000 ) {
-      buttonConfig=buttonConfig+1;
-      if (buttonConfig>3) buttonConfig=0;
+    if (pressDuration < 1000) {
+      buttonConfig = buttonConfig + 1;
+      if (buttonConfig > 3) buttonConfig = 0;
     }
   }
 
-  if (lastState == LOW && currentState == LOW){
-     long passedDuration = millis() - pressedTime;
-      if( passedDuration > 4000 ) {
-          updateOLED2("Saved", "Release", "Button Now");
-          delay(1000);
-          updateOLED2("Rebooting", "in", "5 seconds");
-          delay(5000);
-          EEPROM.write(addr, char(buttonConfig));
-          EEPROM.commit();
-          delay(1000);
-          ESP.restart();
+  if (lastState == LOW && currentState == LOW) {
+    long passedDuration = millis() - pressedTime;
+    if (passedDuration > 4000) {
+      updateOLED2("Saved", "Release", "Button Now");
+      delay(1000);
+      updateOLED2("Rebooting", "in", "5 seconds");
+      delay(5000);
+      EEPROM.write(addr, char(buttonConfig));
+      EEPROM.commit();
+      delay(1000);
+      ESP.restart();
     }
 
   }
@@ -322,44 +307,43 @@ void inConf(){
   inConf();
 }
 
-
 void setConfig() {
   if (buttonConfig == 0) {
     updateOLED2("Temp. in C", "PM in ug/m3", "Long Press Saves");
-      u8g2.setDisplayRotation(U8G2_R0);
-      inF = false;
-      inUSAQI = false;
+    u8g2.setDisplayRotation(U8G2_R0);
+    inF = false;
+    inUSAQI = false;
   }
-    if (buttonConfig == 1) {
+  if (buttonConfig == 1) {
     updateOLED2("Temp. in C", "PM in US AQI", "Long Press Saves");
-      u8g2.setDisplayRotation(U8G2_R0);
-      inF = false;
-      inUSAQI = true;
+    u8g2.setDisplayRotation(U8G2_R0);
+    inF = false;
+    inUSAQI = true;
   } else if (buttonConfig == 2) {
     updateOLED2("Temp. in F", "PM in ug/m3", "Long Press Saves");
     u8g2.setDisplayRotation(U8G2_R0);
-      inF = true;
-      inUSAQI = false;
-  } else  if (buttonConfig == 3) {
+    inF = true;
+    inUSAQI = false;
+  } else if (buttonConfig == 3) {
     updateOLED2("Temp. in F", "PM in US AQI", "Long Press Saves");
-      u8g2.setDisplayRotation(U8G2_R0);
-       inF = true;
-      inUSAQI = true;
+    u8g2.setDisplayRotation(U8G2_R0);
+    inF = true;
+    inUSAQI = true;
   }
 }
 
 void switchLED(boolean ledON) {
- if (ledON) {
-     digitalWrite(10, HIGH);
+  if (ledON) {
+    digitalWrite(10, HIGH);
   } else {
     digitalWrite(10, LOW);
   }
 }
 
-void sendPing(){
-      String payload = "{\"wifi\":" + String(WiFi.RSSI())
-    + ", \"boot\":" + loopCount
-    + "}";
+void sendPing() {
+  String payload = "{\"wifi\":" + String(WiFi.RSSI()) +
+    ", \"boot\":" + loopCount +
+    "}";
 }
 
 void updateOLED2(String ln1, String ln2, String ln3) {
@@ -367,49 +351,48 @@ void updateOLED2(String ln1, String ln2, String ln3) {
   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() );
+    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))
-      + (pm01 < 0 ? "" : ", \"pm01\":" + String(pm01))
-      + (pm25 < 0 ? "" : ", \"pm02\":" + String(pm25))
-      + (pm10 < 0 ? "" : ", \"pm10\":" + String(pm10))
-      + (pm03PCount < 0 ? "" : ", \"pm003_count\":" + String(pm03PCount))
-      + (TVOC < 0 ? "" : ", \"tvoc_index\":" + String(TVOC))
-      + (NOX < 0 ? "" : ", \"nox_index\":" + String(NOX))
-      + ", \"atmp\":" + String(temp)
-      + (hum < 0 ? "" : ", \"rhum\":" + String(hum))
-      + ", \"boot\":" + loopCount
-      + "}";
+  if (currentMillis - previoussendToServer >= sendToServerInterval) {
+    previoussendToServer += sendToServerInterval;
+    String payload = "{\"wifi\":" + String(WiFi.RSSI()) +
+      (Co2 < 0 ? "" : ", \"rco2\":" + String(Co2)) +
+      (pm01 < 0 ? "" : ", \"pm01\":" + String(pm01)) +
+      (pm25 < 0 ? "" : ", \"pm02\":" + String(pm25)) +
+      (pm10 < 0 ? "" : ", \"pm10\":" + String(pm10)) +
+      (pm03PCount < 0 ? "" : ", \"pm003_count\":" + String(pm03PCount)) +
+      (TVOC < 0 ? "" : ", \"tvoc_index\":" + String(TVOC)) +
+      (NOX < 0 ? "" : ", \"nox_index\":" + String(NOX)) +
+      ", \"atmp\":" + String(temp) +
+      (hum < 0 ? "" : ", \"rhum\":" + String(hum)) +
+      ", \"boot\":" + loopCount +
+      "}";
 
-      if(WiFi.status()== WL_CONNECTED){
-        Serial.println(payload);
-        String POSTURL = APIROOT + "sensors/airgradient:" + String(getNormalizedMac()) + "/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();
-        resetWatchdog();
-        loopCount++;
-      }
-      else {
-        Serial.println("WiFi Disconnected");
-      }
-   }
+    if (WiFi.status() == WL_CONNECTED) {
+      Serial.println(payload);
+      String POSTURL = APIROOT + "sensors/airgradient:" + String(getNormalizedMac()) + "/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();
+      resetWatchdog();
+      loopCount++;
+    } else {
+      Serial.println("WiFi Disconnected");
+    }
+  }
 }
 
 void countdown(int from) {
@@ -423,46 +406,45 @@ void countdown(int from) {
 }
 
 void resetWatchdog() {
-    digitalWrite(2, HIGH);
-    delay(20);
-    digitalWrite(2, LOW);
+  Serial.println("Watchdog reset");
+  digitalWrite(2, HIGH);
+  delay(20);
+  digitalWrite(2, LOW);
 }
 
 // Wifi Manager
- void connectToWifi() {
-   WiFiManager wifiManager;
-   switchLED(true);
-   //WiFi.disconnect(); //to delete previous saved hotspot
-   String HOTSPOT = "AG-" + String(getNormalizedMac());
-   wifiManager.setTimeout(180);
-
-
-   if (!wifiManager.autoConnect((const char * ) HOTSPOT.c_str())) {
+void connectToWifi() {
+  WiFiManager wifiManager;
+  switchLED(true);
+  //WiFi.disconnect(); //to delete previous saved hotspot
+  String HOTSPOT = "AG-" + String(getNormalizedMac());
+  wifiManager.setTimeout(180);
+  if (!wifiManager.autoConnect((const char * ) HOTSPOT.c_str())) {
     switchLED(false);
-     Serial.println("failed to connect and hit timeout");
-     delay(6000);
-   }
+    Serial.println("failed to connect and hit timeout");
+    delay(6000);
+  }
 
 }
 
 void debug(String msg) {
   if (DEBUG)
-  Serial.print(msg);
+    Serial.print(msg);
 }
 
 void debug(int msg) {
   if (DEBUG)
-  Serial.print(msg);
+    Serial.print(msg);
 }
 
 void debugln(String msg) {
   if (DEBUG)
-  Serial.println(msg);
+    Serial.println(msg);
 }
 
 void debugln(int msg) {
   if (DEBUG)
-  Serial.println(msg);
+    Serial.println(msg);
 }
 
 String getNormalizedMac() {
@@ -472,6 +454,68 @@ String getNormalizedMac() {
   return mac;
 }
 
+void setRGBledCO2color(int co2Value) {
+  if (co2Value < 800) setRGBledColor('g');
+  if (co2Value >= 800 && co2Value < 1000) setRGBledColor('y');
+  if (co2Value >= 1000 && co2Value < 1500) setRGBledColor('o');
+  if (co2Value >= 1500 && co2Value < 2000) setRGBledColor('r');
+  if (co2Value >= 2000 && co2Value < 3000) setRGBledColor('p');
+  if (co2Value >= 3000 && co2Value < 10000) setRGBledColor('b');
+}
+
+void setRGBledColor(char color) {
+  if (useRGBledBar) {
+    //pixels.clear();
+    switch (color) {
+    case 'g':
+      for (int i = 0; i < 11; i++) {
+        pixels.setPixelColor(i, pixels.Color(0, 255, 0));
+        delay(100);
+        pixels.show();
+      }
+      break;
+    case 'y':
+      for (int i = 0; i < 11; i++) {
+        pixels.setPixelColor(i, pixels.Color(255, 255, 0));
+        delay(100);
+        pixels.show();
+      }
+      break;
+    case 'o':
+      for (int i = 0; i < 11; i++) {
+        pixels.setPixelColor(i, pixels.Color(255, 128, 0));
+        delay(100);
+        pixels.show();
+      }
+      break;
+    case 'r':
+      for (int i = 0; i < 11; i++) {
+        pixels.setPixelColor(i, pixels.Color(255, 0, 0));
+        delay(100);
+        pixels.show();
+      }
+      break;
+    case 'p':
+      for (int i = 0; i < 11; i++) {
+        pixels.setPixelColor(i, pixels.Color(153, 0, 153));
+        delay(100);
+        pixels.show();
+      }
+      break;
+    case 'b':
+      for (int i = 0; i < 11; i++) {
+        pixels.setPixelColor(i, pixels.Color(102, 0, 0));
+        delay(100);
+        pixels.show();
+      }
+      break;
+    default:
+      // if nothing else matches, do the default
+      // default is optional
+      break;
+    }
+  }
+}
 
 // Calculate PM2.5 US AQI
 int PM_TO_AQI_US(int pm02) {