diff --git a/examples/OneOpenAir/OneOpenAir.ino b/examples/OneOpenAir/OneOpenAir.ino
index 240cfaf..52a4190 100644
--- a/examples/OneOpenAir/OneOpenAir.ino
+++ b/examples/OneOpenAir/OneOpenAir.ino
@@ -82,7 +82,7 @@ static WifiConnector wifiConnector(oledDisplay, Serial, stateMachine,
                                    configuration);
 static OpenMetrics openMetrics(measurements, configuration, wifiConnector,
                                apiClient);
-static OtaHandler otaHandler;
+static OtaHandler otaHandler(stateMachine, configuration);
 static LocalServer localServer(Serial, openMetrics, measurements, configuration,
                                wifiConnector);
 
@@ -157,6 +157,7 @@ void setup() {
   apiClient.setAirGradient(ag);
   openMetrics.setAirGradient(ag);
   localServer.setAirGraident(ag);
+  otaHandler.setAirGradient(ag);
 
   /** Connecting wifi */
   bool connectToWifi = false;
@@ -184,7 +185,7 @@ void setup() {
         #ifdef ESP8266
           // ota not supported
         #else
-          otaHandler.updateFirmwareIfOutdated(ag->deviceId());
+          // otaHandler.updateFirmwareIfOutdated(ag->deviceId());
         #endif
 
         apiClient.fetchServerConfiguration();
@@ -733,6 +734,11 @@ static void configUpdateHandle() {
                    String(configuration.getDisplayBrightness()));
   }
 
+  String newVer = configuration.newFirmwareVersion();
+  if (newVer.length()) {
+    otaHandler.updateFirmwareIfOutdated(newVer);
+  }
+
   appDispHandler();
   appLedHandler();
 }
diff --git a/examples/OneOpenAir/OtaHandler.h b/examples/OneOpenAir/OtaHandler.h
index 067d5bf..8775503 100644
--- a/examples/OneOpenAir/OtaHandler.h
+++ b/examples/OneOpenAir/OtaHandler.h
@@ -5,8 +5,11 @@
 #include <esp_err.h>
 #include <esp_http_client.h>
 #include <esp_ota_ops.h>
+#include "AgConfigure.h"
+#include "AgStateMachine.h"
+#include "AirGradient.h"
 
-#define OTA_BUF_SIZE 512
+#define OTA_BUF_SIZE 1024
 #define URL_BUF_SIZE 256
 
 enum OtaUpdateOutcome {
@@ -18,10 +21,23 @@ enum OtaUpdateOutcome {
 
 class OtaHandler {
 public:
-  void updateFirmwareIfOutdated(String deviceId) {
+  OtaHandler(StateMachine &sm, Configuration &config)
+      : sm(sm), config(config) {}
+  void setAirGradient(AirGradient *ag) { this->ag = ag; };
 
-    String url = "http://hw.airgradient.com/sensors/airgradient:" + deviceId +
-                 "/generic/os/firmware.bin";
+  void updateFirmwareIfOutdated(String newVersion) {
+    int lastOta = config.getLastOta();
+    // Retry OTA after last udpate 24h
+    if (lastOta != 0 && lastOta < (60 * 60 * 24)) {
+      Serial.println("Ignore OTA cause last update is " + String(lastOta) +
+                     String("sec"));
+      Serial.println("Retry again after 24h");
+      return;
+    }
+
+    String url =
+        "http://hw.airgradient.com/sensors/airgradient:" + ag->deviceId() +
+        "/generic/os/firmware.bin";
     url += "?current_firmware=";
     url += GIT_VERSION;
     char urlAsChar[URL_BUF_SIZE];
@@ -30,16 +46,31 @@ public:
 
     esp_http_client_config_t config = {};
     config.url = urlAsChar;
-    esp_err_t ret = attemptToPerformOta(&config);
+    OtaUpdateOutcome ret = attemptToPerformOta(&config, newVersion);
+
+    // Update last OTA time whatever result.
+    this->config.updateLastOta();
+
     Serial.println(ret);
     if (ret == OtaUpdateOutcome::UPDATE_PERFORMED) {
       Serial.println("OTA update performed, restarting ...");
+      int i = 6;
+      while (i != 0) {
+        i = i - 1;
+        sm.executeOTA(StateMachine::OtaState::OTA_STATE_SUCCESS, "", i);
+        delay(1000);
+      }
       esp_restart();
     }
   }
 
 private:
-  OtaUpdateOutcome attemptToPerformOta(const esp_http_client_config_t *config) {
+  AirGradient *ag;
+  StateMachine &sm;
+  Configuration &config;
+
+  OtaUpdateOutcome attemptToPerformOta(const esp_http_client_config_t *config,
+                                       String newVersion) {
     esp_http_client_handle_t client = esp_http_client_init(config);
     if (client == NULL) {
       Serial.println("Failed to initialize HTTP connection");
@@ -94,6 +125,14 @@ private:
     }
 
     int binary_file_len = 0;
+    int totalSize = esp_http_client_get_content_length(client);
+    Serial.println("File size: " + String(totalSize) + String(" bytes"));
+
+    // Show display start update new firmware.
+    sm.executeOTA(StateMachine::OtaState::OTA_STATE_BEGIN, newVersion, 0);
+
+    // Download file and write new firmware to OTA partition
+    uint32_t lastUpdate = millis();
     while (1) {
       int data_read =
           esp_http_client_read(client, upgrade_data_buf, OTA_BUF_SIZE);
@@ -103,16 +142,25 @@ private:
       }
       if (data_read < 0) {
         Serial.println("Data read error");
+        sm.executeOTA(StateMachine::OtaState::OTA_STATE_FAIL, "", 0);
         break;
       }
       if (data_read > 0) {
         ota_write_err = esp_ota_write(
             update_handle, (const void *)upgrade_data_buf, data_read);
         if (ota_write_err != ESP_OK) {
+          sm.executeOTA(StateMachine::OtaState::OTA_STATE_FAIL, "", 0);
           break;
         }
         binary_file_len += data_read;
-        // Serial.printf("Written image length %d\n", binary_file_len);
+
+        int percent = (binary_file_len * 100) / totalSize;
+        uint32_t ms = (uint32_t)(millis() - lastUpdate);
+        if (ms >= 250) {
+          sm.executeOTA(StateMachine::OtaState::OTA_STATE_PROCESSING, "",
+                        percent);
+          lastUpdate = millis();
+        }
       }
     }
     free(upgrade_data_buf);
diff --git a/src/AgConfigure.cpp b/src/AgConfigure.cpp
index 7027895..2c3cdad 100644
--- a/src/AgConfigure.cpp
+++ b/src/AgConfigure.cpp
@@ -6,6 +6,7 @@
 #else
 #include "EEPROM.h"
 #endif
+#include <time.h>
 
 #define EEPROM_CONFIG_SIZE 512
 #define CONFIG_FILE_NAME "/cfg.bin"
@@ -163,6 +164,7 @@ void Configuration::defaultConfig(void) {
   config.temperatureUnit = 'c';
   config.ledBarBrightness = 100;
   config.displayBrightness = 100;
+  config.lastOta = 0;
 
   saveConfig();
 }
@@ -171,7 +173,10 @@ void Configuration::defaultConfig(void) {
  * @brief Show configuration as JSON string message over log
  *
  */
-void Configuration::printConfig(void) { logInfo(toString().c_str()); }
+void Configuration::printConfig(void) {
+  logInfo(toString().c_str());
+  logInfo("Last OTA time: " + String(config.lastOta));
+}
 
 /**
  * @brief Construct a new Ag Configure:: Ag Configure object
@@ -638,6 +643,18 @@ bool Configuration::parse(String data, bool isLocal) {
     }
   }
 
+  if (JSON.typeof_(root["targetFirmware"]) == "string") {
+    String newVer = root["targetFirmware"];
+    String curVer = String(GIT_VERSION);
+    if (curVer != newVer) {
+      logInfo("Detected new firwmare version: " + newVer);
+      otaNewFirmwareVersion = newVer;
+      udpated = true;
+    } else {
+      otaNewFirmwareVersion = String("");
+    }
+  }
+
   if (changed) {
     udpated = true;
     saveConfig();
@@ -938,3 +955,52 @@ bool Configuration::isDisplayBrightnessChanged(void) {
   displayBrightnessChanged = false;
   return changed;
 }
+
+/**
+ * @brief Get number of sec from last OTA
+ *
+ * @return int < 0 is invalid, 0 mean there is no OTA trigger.
+ */
+int Configuration::getLastOta(void) {
+  struct tm timeInfo;
+  if (getLocalTime(&timeInfo) == false) {
+    logError("Get localtime failed");
+    return -1;
+  }
+  int curYear = timeInfo.tm_year + 1900;
+  if (curYear < 2024) {
+    logError("Current year " + String(curYear) + String(" invalid"));
+    return -1;
+  }
+  time_t curTime = mktime(&timeInfo);
+  logInfo("Last ota time: " + String(config.lastOta));
+  if (config.lastOta == 0) {
+    return 0;
+  }
+
+  int sec = curTime - config.lastOta;
+  logInfo("Last ota secconds: " + String(sec));
+  return sec;
+}
+
+void Configuration::updateLastOta(void) {
+  struct tm timeInfo;
+  if (getLocalTime(&timeInfo) == false) {
+    logError("updateLastOta: Get localtime failed");
+    return;
+  }
+  int curYear = timeInfo.tm_year + 1900;
+  if (curYear < 2024) {
+    logError("updateLastOta: lolcal time invalid");
+    return;
+  }
+  config.lastOta = mktime(&timeInfo);
+  logInfo("Last OTA: " + String(config.lastOta));
+  saveConfig();
+}
+
+String Configuration::newFirmwareVersion(void) {
+  String newFw = otaNewFirmwareVersion;
+  otaNewFirmwareVersion = String("");
+  return newFw;
+}
diff --git a/src/AgConfigure.h b/src/AgConfigure.h
index 6759ba6..bb07626 100644
--- a/src/AgConfigure.h
+++ b/src/AgConfigure.h
@@ -28,6 +28,7 @@ private:
     int tvocLearningOffset;
     int noxLearningOffset;
     char temperatureUnit; // 'f' or 'c'
+    time_t lastOta;
 
     uint32_t _check;
   };
@@ -40,6 +41,7 @@ private:
   bool _tvocLearningOffsetChanged;
   bool ledBarBrightnessChanged = false;
   bool displayBrightnessChanged = false;
+  String otaNewFirmwareVersion;
 
   AirGradient* ag;
 
@@ -97,6 +99,9 @@ public:
   int getLedBarBrightness(void);
   bool isDisplayBrightnessChanged(void);
   int getDisplayBrightness(void);
+  int getLastOta(void);
+  void updateLastOta(void);
+  String newFirmwareVersion(void);
 };
 
 #endif /** _AG_CONFIG_H_ */
diff --git a/src/AgOledDisplay.cpp b/src/AgOledDisplay.cpp
index 8a033bb..3e20c54 100644
--- a/src/AgOledDisplay.cpp
+++ b/src/AgOledDisplay.cpp
@@ -50,6 +50,16 @@ void OledDisplay::showTempHum(bool hasStatus) {
   }
 }
 
+void OledDisplay::setCentralText(int y, String text) {
+  setCentralText(y, text.c_str());
+}
+
+void OledDisplay::setCentralText(int y, const char *text) {
+  int x = (DISP()->getWidth() - DISP()->getStrWidth(text)) / 2;
+  DISP()->drawStr(x, y, text);
+}
+
+
 /**
  * @brief Construct a new Ag Oled Display:: Ag Oled Display object
  * 
@@ -314,3 +324,42 @@ void OledDisplay::showWiFiQrCode(String content, String label) {
 void OledDisplay::setBrightness(int percent) {
   DISP()->setContrast((127 * percent) / 100);
 }
+
+void OledDisplay::showNewFirmwareVersion(String version) {
+  DISP()->firstPage();
+  do {
+    DISP()->setFont(u8g2_font_t0_16_tf);
+    setCentralText(20, "Firmware Update");
+    setCentralText(40, "New version");
+    setCentralText(60, version.c_str());
+  } while (DISP()->nextPage());
+}
+
+void OledDisplay::showNewFirmwareUpdating(String percent) {
+  DISP()->firstPage();
+  do {
+    DISP()->setFont(u8g2_font_t0_16_tf);
+    setCentralText(20, "Firmware Update");
+    setCentralText(50, String("Updating... ") + percent + String("%"));
+  } while (DISP()->nextPage());
+}
+
+void OledDisplay::showNewFirmwareSuccess(String count) {
+  DISP()->firstPage();
+  do {
+    DISP()->setFont(u8g2_font_t0_16_tf);
+    setCentralText(20, "Firmware Update");
+    setCentralText(40, "Success");
+    setCentralText(60, String("Rebooting... ") + count);
+  } while (DISP()->nextPage());
+}
+
+void OledDisplay::showNewFirmwareFailed(void) {
+  DISP()->firstPage();
+  do {
+    DISP()->setFont(u8g2_font_t0_16_tf);
+    setCentralText(20, "Firmware Update");
+    setCentralText(40, "Failed");
+    setCentralText(60, String("Retry after 24h"));
+  } while (DISP()->nextPage());
+}
diff --git a/src/AgOledDisplay.h b/src/AgOledDisplay.h
index 69fb398..4a5044b 100644
--- a/src/AgOledDisplay.h
+++ b/src/AgOledDisplay.h
@@ -16,6 +16,9 @@ private:
   Measurements &value;
 
   void showTempHum(bool hasStatus);
+  void setCentralText(int y, String text);
+  void setCentralText(int y, const char *text);
+
 public:
   OledDisplay(Configuration &config, Measurements &value,
                 Stream &log);
@@ -33,6 +36,10 @@ public:
   void showDashboard(const char *status);
   void showWiFiQrCode(String content, String label);
   void setBrightness(int percent);
+  void showNewFirmwareVersion(String version);
+  void showNewFirmwareUpdating(String percent);
+  void showNewFirmwareSuccess(String count);
+  void showNewFirmwareFailed(void);
 };
 
 #endif /** _AG_OLED_DISPLAY_H_ */
diff --git a/src/AgStateMachine.cpp b/src/AgStateMachine.cpp
index 5efb6f7..57635fe 100644
--- a/src/AgStateMachine.cpp
+++ b/src/AgStateMachine.cpp
@@ -759,3 +759,47 @@ void StateMachine::executeCo2Calibration(void) {
 void StateMachine::executeLedBarTest(void) {
   handleLeds(AgStateMachineLedBarTest);
 }
+
+void StateMachine::executeOTA(StateMachine::OtaState state, String msg,
+                              int processing) {
+  switch (state) {
+  case OtaState::OTA_STATE_BEGIN: {
+    if (ag->isOne()) {
+      disp.showNewFirmwareVersion(msg);
+    } else {
+      logInfo("New firmware: " + msg);
+    }
+    delay(2500);
+    break;
+  }
+  case OtaState::OTA_STATE_FAIL: {
+    if (ag->isOne()) {
+      disp.showNewFirmwareFailed();
+    } else {
+      logError("Firmware update: failed");
+    }
+
+    delay(2500);
+    break;
+  }
+  case OtaState::OTA_STATE_PROCESSING: {
+    if (ag->isOne()) {
+      disp.showNewFirmwareUpdating(String(processing));
+    } else {
+      logInfo("Firmware update: " + String(processing) + String("%"));
+    }
+
+    break;
+  }
+  case OtaState::OTA_STATE_SUCCESS: {
+    if (ag->isOne()) {
+      disp.showNewFirmwareSuccess(String(processing));
+    } else {
+      logInfo("Rebooting... " + String(processing));
+    }
+    break;
+  }
+  default:
+    break;
+  }
+}
diff --git a/src/AgStateMachine.h b/src/AgStateMachine.h
index 7299bb3..a783810 100644
--- a/src/AgStateMachine.h
+++ b/src/AgStateMachine.h
@@ -49,6 +49,14 @@ public:
   AgStateMachineState getLedState(void);
   void executeCo2Calibration(void);
   void executeLedBarTest(void);
+
+  enum OtaState {
+    OTA_STATE_BEGIN,
+    OTA_STATE_FAIL,
+    OTA_STATE_PROCESSING,
+    OTA_STATE_SUCCESS
+  };
+  void executeOTA(OtaState state, String msg, int processing);
 };
 
 #endif /** _AG_STATE_MACHINE_H_ */
diff --git a/src/AgWiFiConnector.cpp b/src/AgWiFiConnector.cpp
index 0e7f291..8ac9495 100644
--- a/src/AgWiFiConnector.cpp
+++ b/src/AgWiFiConnector.cpp
@@ -1,5 +1,6 @@
 #include "AgWiFiConnector.h"
 #include "Libraries/WiFiManager/WiFiManager.h"
+#include <time.h>
 
 #define WIFI_CONNECT_COUNTDOWN_MAX 180
 #define WIFI_HOTSPOT_PASSWORD_DEFAULT "cleanair"
@@ -158,6 +159,11 @@ bool WifiConnector::connect(void) {
       config.setPostToAirGradient(result != "T");
     }
     hasPortalConfig = false;
+
+    /** Configure internet time */
+    const char *ntp_server = "pool.ntp.org";
+    configTime(0, 0, ntp_server);
+    logInfo("Set internet time server: " + String(ntp_server));
   }
 #else
   _wifiProcess();
diff --git a/src/App/AppDef.h b/src/App/AppDef.h
index 7009f92..2cc8ee8 100644
--- a/src/App/AppDef.h
+++ b/src/App/AppDef.h
@@ -60,6 +60,9 @@ enum AgStateMachineState {
   /* LED bar testing */
   AgStateMachineLedBarTest,
 
+  /** OTA perform, show display status */
+  AgStateMachineOtaPerform,
+
   /** LED: Show working state.
    * Display: Show dashboard */
   AgStateMachineNormal,