diff --git a/envisens/envisens_esp_fw/envisens_esp_fw.ino b/envisens/envisens_esp_fw/envisens_esp_fw.ino
index c186f02..8b74514 100644
--- a/envisens/envisens_esp_fw/envisens_esp_fw.ino
+++ b/envisens/envisens_esp_fw/envisens_esp_fw.ino
@@ -18,14 +18,18 @@
 #define TOPIC_HMID TOPIC_BASE "humidity"
 #define TOPIC_HEAT TOPIC_BASE "heat_index"
 #define TOPIC_AIRQ TOPIC_BASE "air_gas"
+#define TOPIC_ABHU TOPIC_BASE "abs_humidity"
 
 #define DIFF_TEMP 0.3 // sensor has only 0.5°C accuracy, triggering on less is ludicrous
 #define DIFF_HMID 2.5 // humidity doesn't change that much anyways
 #define DIFF_HEAT 0.2 // this one's actually quite active
 #define DIFF_AIRQ 3 // this one hardly changes 
+#define DIFF_ABHU 0.1 // small changes mean quite something
 
 float hmid = 0; // humidity
 float hmid_r = 0; // humidity
+float abhu = 0; // absolute humidity
+float abhu_r = 0; // absolute humidity
 float temp = 0; // temperature
 float temp_r = 0; // temperature
 float heat = 0; // heat index
@@ -122,8 +126,6 @@ bool publish (String desc, char *topic, float val, float &lastVal, float diff, b
       Serial.print("** ERROR: Value out of bounds, not published. Last value :");
       Serial.println(String(lastVal).c_str());
     }
-  } else {
-    Serial.println("Not enough variation for a publication");
   }
   return retval;
 }
@@ -181,6 +183,10 @@ void loop() {
       Serial.println("ERR: Sensor could not be identified");
     }
 
+    if (!isnan(hmid) && !isnan(temp)){
+      abhu = (6.112 * ( pow(2.71828, ((17.67 * temp) / (temp + 243.5))) * hmid * 2.1674)) / (273.15 + temp);
+    }
+
     published = false;
     if (lastSent > FORCE_PERIOD) {
       Serial.println(F("Forcing a publish of all values"));
@@ -192,6 +198,7 @@ void loop() {
     published += publish("humidity", TOPIC_HMID, hmid, hmid_r, DIFF_HMID, forcePublish);
     published += publish("heat index", TOPIC_HEAT, heat, heat_r, DIFF_HEAT, forcePublish);
     published += publish("air quality", TOPIC_AIRQ, airq, airq_r, DIFF_AIRQ, forcePublish);
+    published += publish("absolute humidity", TOPIC_ABHU, abhu, abhu_r, DIFF_ABHU, forcePublish);
     
     if (published == false) {
       lastSent = lastSent + 1;