Fixing set_temperature_offset

Give the sensor some time to adjust
Display the applied offset on the webpage, not just the parameter

ampel-firmware/co2_sensor.cpp

@@ -52,6 +52,10 @@ namespace sensor {
 
   state current_state = BOOTUP;
   void switchState(state);
+  void setCO2forDebugging(int32_t fakeCo2);
+  void calibrateSensorToSpecificPPM(int32_t calibrationLevel);
+  void calibrateSensorRightNow(int32_t calibrationLevel);
+  void setAutoCalibration(int32_t autoCalibration);
 
   void initialize() {
 #if defined(ESP8266)
@@ -82,14 +86,17 @@ namespace sensor {
     // for acclimatization. Resetting it after startup seems to fix this behaviour.
     scd30.reset();
 
+    //NOTE: It seems that the sensor needs some time for getting/setting temperature offset.
+    delay(500);
     Serial.print(F("Setting temperature offset to -"));
     Serial.print(abs(config::temperature_offset));
     Serial.println(F(" K."));
     scd30.setTemperatureOffset(abs(config::temperature_offset)); // setTemperatureOffset only accepts positive numbers, but shifts the temperature down.
-    delay(100);
+    delay(500);
 
-    Serial.print(F("Temperature offset is : -"));
-    Serial.print(scd30.getTemperatureOffset());
+    //NOTE: Even once the temperature offset is saved, the sensor still needs some time (~10 minutes?) to apply it.
+    Serial.print(F("Temperature offset is : "));
+    Serial.print(getTemperatureOffset());
     Serial.println(F(" K"));
 
     Serial.print(F("Auto-calibration is "));
@@ -281,6 +288,10 @@ namespace sensor {
     return freshData && (current_state == READY || current_state == NEEDS_CALIBRATION);
   }
 
+  float getTemperatureOffset() {
+    return -abs(scd30.getTemperatureOffset());
+  }
+
   /*****************************************************************
    * Callbacks for sensor commands                                 *
    *****************************************************************/

ampel-firmware/co2_sensor.h

@@ -12,12 +12,8 @@ namespace sensor {
   void initialize();
   bool processData();
   void startCalibrationProcess();
-
-  void setCO2forDebugging(int32_t fakeCo2);
   void setTimer(int32_t timestep);
-  void calibrateSensorToSpecificPPM(int32_t calibrationLevel);
-  void calibrateSensorRightNow(int32_t calibrationLevel);
-  void setAutoCalibration(int32_t autoCalibration);
   void resetSCD();
+  float getTemperatureOffset();
 }
 #endif

ampel-firmware/web_server.cpp

@@ -29,11 +29,11 @@ namespace web_server {
   void handleDeleteCSV();
   void handleWebServerCSV();
 
-  const __FlashStringHelper* showHTMLIf(bool is_active){
+  const __FlashStringHelper* showHTMLIf(bool is_active) {
     return is_active ? F("") : F("hidden");
   }
 
-  const __FlashStringHelper* yesOrNo(bool is_active){
+  const __FlashStringHelper* yesOrNo(bool is_active) {
     return is_active ? F("Yes") : F("No");
   }
 
@@ -63,37 +63,13 @@ namespace web_server {
             "<li class='pure-menu-item'><a href='#graph' class='pure-menu-link'>Graph</a></li>"
             "<li class='pure-menu-item'><a href='#log' class='pure-menu-link'>Log</a></li>");
 
-    body1_template = PSTR("<li class='pure-menu-item'><a href='%s' class='pure-menu-link'>Download CSV</a></li>"
-        "<li class='pure-menu-item' id='led'>&#11044;</li>" // LED
-        "</ul></div></div>"
-        "<script>"
-        // Show a colored dot on the webpage, with a similar color than on LED Ring.
-        "hue=(1-(Math.min(Math.max(parseInt(document.title),500),1600)-500)/1100)*120;"
-        "document.getElementById('led').style.color=['hsl(',hue,',100%%,50%%)'].join('');"
-        "</script>"
-        "<div class='pure-g'>"
-        "<div class='pure-u-1' id='graph'></div>"// Graph placeholder
-        "</div>"
-        "<div class='pure-g'>"
-        "<table id='table' class='pure-table-striped pure-u-1 pure-u-md-1-2'>"
-        "<tr><th colspan='2'>%s</th></tr>"
-        "<tr><td>CO<sub>2</sub></td><td>%5d ppm</td></tr>"
-        "<tr><td>Temperature</td><td>%.1f&#8451;</td></tr>"
-        "<tr><td>Humidity</td><td>%.1f%%</td></tr>"
-        "<tr><td>Last measurement</td><td>%s</td></tr>"
-        "<tr><td>Timestep</td><td>%5d s</td></tr>"
-        "<tbody %s>"
-        "<tr><th colspan='2'>CSV</th></tr>"
-        "<tr><td>Last write</td><td>%s</td></tr>"
-        "<tr><td>Interval</td><td>%5d s</td></tr>"
-        "<tr><td>Available space</td><td>%d kB</td></tr>"
-        "</tbody>"
-        "<tbody %s>"
-        "<tr><th colspan='2'>MQTT</th></tr>"
-        "<tr><td>Connected?</td><td>%s</td></tr>"
-        "<tr><td>Last publish</td><td>%s</td></tr>"
-        "<tr><td>Interval</td><td>%5d s</td></tr>"
-        "</tbody>"
+    body1_template =
+        PSTR(
+            "<li class='pure-menu-item'><a href='%s' class='pure-menu-link'>Download CSV</a></li>" "<li class='pure-menu-item' id='led'>&#11044;</li>" // LED
+            "</ul></div></div>" "<script>"
+            // Show a colored dot on the webpage, with a similar color than on LED Ring.
+            "hue=(1-(Math.min(Math.max(parseInt(document.title),500),1600)-500)/1100)*120;" "document.getElementById('led').style.color=['hsl(',hue,',100%%,50%%)'].join('');" "</script>" "<div class='pure-g'>" "<div class='pure-u-1' id='graph'></div>"// Graph placeholder
+            "</div>" "<div class='pure-g'>" "<table id='table' class='pure-table-striped pure-u-1 pure-u-md-1-2'>" "<tr><th colspan='2'>%s</th></tr>" "<tr><td>CO<sub>2</sub></td><td>%5d ppm</td></tr>" "<tr><td>Temperature</td><td>%.1f&#8451;</td></tr>" "<tr><td>Humidity</td><td>%.1f%%</td></tr>" "<tr><td>Last measurement</td><td>%s</td></tr>" "<tr><td>Timestep</td><td>%5d s</td></tr>" "<tbody %s>" "<tr><th colspan='2'>CSV</th></tr>" "<tr><td>Last write</td><td>%s</td></tr>" "<tr><td>Interval</td><td>%5d s</td></tr>" "<tr><td>Available space</td><td>%d kB</td></tr>" "</tbody>" "<tbody %s>" "<tr><th colspan='2'>MQTT</th></tr>" "<tr><td>Connected?</td><td>%s</td></tr>" "<tr><td>Last publish</td><td>%s</td></tr>" "<tr><td>Interval</td><td>%5d s</td></tr>" "</tbody>"
 #if defined(ESP32)
         "<tbody %s>"
         "<tr><th colspan='2'>LoRaWAN</th></tr>"
@@ -103,7 +79,7 @@ namespace web_server {
         "<tr><td>Interval</td><td>%5d s</td></tr>"
         "</tbody>"
 #endif
-        );
+            );
 
     body2_template =
         PSTR(
@@ -229,8 +205,8 @@ namespace web_server {
     snprintf_P(content, sizeof(content), body1_template, csv_writer::filename, config::ampel_name(), sensor::co2,
         sensor::temperature, sensor::humidity, sensor::timestamp, config::measurement_timestep,
         showHTMLIf(config::is_csv_active()), csv_writer::last_successful_write, config::csv_interval,
-        csv_writer::getAvailableSpace() / 1024, showHTMLIf(config::is_mqtt_active()),
-        yesOrNo(mqtt::connected), mqtt::last_successful_publish, config::mqtt_sending_interval
+        csv_writer::getAvailableSpace() / 1024, showHTMLIf(config::is_mqtt_active()), yesOrNo(mqtt::connected),
+        mqtt::last_successful_publish, config::mqtt_sending_interval
 #if defined(ESP32)
         , showHTMLIf(config::is_lorawan_active()), yesOrNo(lorawan::connected),
         config::lorawan_frequency_plan, lorawan::last_transmission, config::lorawan_sending_interval
@@ -241,7 +217,7 @@ namespace web_server {
     Serial.print(strlen(content));
     web_config::http.sendContent(content);
 
-    snprintf_P(content, sizeof(content), body2_template, config::temperature_offset,
+    snprintf_P(content, sizeof(content), body2_template, sensor::getTemperatureOffset(),
         yesOrNo(config::auto_calibrate_sensor), config::ampel_name(), config::ampel_name(), wifi::local_ip,
         wifi::local_ip, ampel.macAddress, ESP.getFreeHeap(), esp_get_max_free_block_size(),
         esp_get_heap_fragmentation(), ampel.max_loop_duration, ampel.board, ampel.sensorId, ampel.version, dd, hh, mm,