diff --git a/ampel-firmware/co2_sensor.cpp b/ampel-firmware/co2_sensor.cpp
index 196466937e3fe59e5d4e82ec43989a99f1687578..4a4a3bb6387e5bb8bd5c9801f60e609bd7dbe952 100644
--- a/ampel-firmware/co2_sensor.cpp
+++ b/ampel-firmware/co2_sensor.cpp
@@ -261,7 +261,7 @@ namespace sensor {
       last_measurement = now;
       ntp::getLocalTime(timestamp);
       co2 = sensor_S8->get_co2();
-      //TODO: Check if there's really no temperature info available.
+      //NOTE: S8 really doesn't have any temperature or humidity available.
       temperature = 0.0;
       humidity = 0.0;
 
@@ -301,6 +301,7 @@ namespace sensor {
     if (isAutoCalibrationOn != autoCalibration) {
       Serial.print(F("Turn autocalibration "));
       Serial.print(autoCalibration ? F("on") : F("off"));
+      // Default autocalibration period is 180h ~ 1 week
       sensor_S8->set_ABC_period(autoCalibration ? 180 : 0);
       delay(500);
       Serial.println(F(". Done!"));