diff --git a/enviro/__init__.py b/enviro/__init__.py
index 236f280..3669fc1 100644
--- a/enviro/__init__.py
+++ b/enviro/__init__.py
@@ -466,6 +466,20 @@ def upload_readings():
 
   return True
 
+# HASS Discovery
+def hass_discovery():
+  destination = config.destination
+  try:
+    exec(f"import enviro.destinations.{destination}")
+    destination_module = sys.modules[f"enviro.destinations.{destination}"]
+    destination_module.hass_discovery(model)
+    config.hass_discovery_triggered = True
+  except ImportError:
+    logging.error(f"! cannot find destination {destination}")
+    return False
+  except:
+      logging.error(f"Unknown error in setting HASS Discovery")
+
 def startup():
   import sys
 
diff --git a/enviro/config_template.py b/enviro/config_template.py
index a345cc0..bfa263f 100644
--- a/enviro/config_template.py
+++ b/enviro/config_template.py
@@ -35,6 +35,8 @@
 mqtt_broker_password = None
 # mqtt broker if using local SSL
 mqtt_broker_ca_file = None
+# Home Assistant Discovery setting
+hass_discovery = False # This could arguably be set to a text field for better customisability 
 
 # adafruit ui settings
 adafruit_io_username = None
diff --git a/enviro/destinations/mqtt.py b/enviro/destinations/mqtt.py
index 26bde1c..2347c97 100644
--- a/enviro/destinations/mqtt.py
+++ b/enviro/destinations/mqtt.py
@@ -51,3 +51,64 @@ def upload_reading(reading):
     logging.debug(f"  - an exception occurred when uploading.", buf.getvalue())
 
   return UPLOAD_FAILED
+
+def hass_discovery(board_type):
+  mqtt_discovery("Enviro Temperature", "temperature", "°C", "temperature", board_type) # Temperature
+  mqtt_discovery("Enviro Pressure", "pressure", "hPa", "pressure", board_type) # Pressure
+  mqtt_discovery("Enviro Humidity", "humidity", "%", "humidity", board_type) # Humidity
+  mqtt_discovery("Enviro Voltage", "voltage", "V", "voltage", board_type) # Voltage
+  if (board_type == "weather"):
+    mqtt_discovery("Enviro Luminance", "illuminance", "lx", "luminance", board_type) # Luminance
+    mqtt_discovery("Enviro Wind Speed", "wind_speed", "m/s", "wind_speed", board_type) # Wind Speed
+    mqtt_discovery("Enviro Rain", "precipitation", "mm", "rain", board_type) # Rain
+    mqtt_discovery("Enviro Rain Per Second", "precipitation", "mm/s", "rain_per_second", board_type) # Rain Per Second
+    #mqtt_discovery("Enviro Wind Direction", "", "°", "wind_direction", board_type) # Wind Direction //HASS doesn't have a device class for direction//
+  elif (board_type == "grow"):
+    mqtt_discovery("Enviro Luminance", "illuminance", "lx", "luminance", board_type) # Luminance
+    mqtt_discovery("Enviro Moisture A", "humidity", "%", "moisture_a", board_type) # Moisture A
+    mqtt_discovery("Enviro Moisture B", "humidity", "%", "moisture_b", board_type) # Moisture B
+    mqtt_discovery("Enviro Moisture C", "humidity", "%", "moisture_c", board_type) # Moisture C
+  elif (board_type == "indoor"):
+    mqtt_discovery("Enviro Luminance", "illuminance", "lx", "luminance", board_type) # Luminance
+    #mqtt_discovery("Enviro Gas Resistance", "", "Ω", "gas_resistance", board_type) # Gas Resistance //HASS doesn't support resistance as a device class//
+    mqtt_discovery("Enviro AQI", "aqi", "&", "aqi", board_type) # AQI
+    mqtt_discovery("Enviro Colour Temperature", "temperature", "K", "color_temperature", board_type) # Colo(u)r Temperature
+  elif (board_type == "urban"):
+    mqtt_discovery("Enviro Noise", "voltage", "V", "noise", board_type) # Noise
+    mqtt_discovery("Enviro PM1", "pm1", "µg/m³", "pm1", board_type) # PM1
+    mqtt_discovery("Enviro PM2.5", "pm25", "µg/m³", "pm2_5", board_type) # PM2_5
+    mqtt_discovery("Enviro PM10", "pm10", "µg/m³", "pm10", board_type) # PM10
+  
+
+def mqtt_discovery(name, device_class, unit, value_name, model ):
+  server = config.mqtt_broker_address
+  username = config.mqtt_broker_username
+  password = config.mqtt_broker_password
+  nickname = config.nickname
+  from ucollections import OrderedDict
+  obj = OrderedDict({
+    "dev":
+    {
+      "ids":[nickname],
+      "name":nickname,
+      "mdl":"Enviro " + model,
+      "mf":"Pimoroni"
+    },
+    "unit_of_meas":unit,
+    "dev_cla":device_class,
+    "val_tpl":"{{ value_json.readings." + value_name +" }}",
+    "state_cla": "measurement",
+    "stat_t":"enviro/" + nickname,
+    "name":name,
+    "uniq_id":"sensor." + nickname + "." + value_name,
+  })
+  try:
+    # attempt to publish reading
+    mqtt_client = MQTTClient(nickname, server, user=username, password=password, keepalive=60)
+    mqtt_client.connect()
+    mqtt_client.publish(f"homeassistant/sensor/{nickname}/{value_name}/config", ujson.dumps(obj), retain=True)
+    mqtt_client.disconnect()
+    return UPLOAD_SUCCESS
+  except:
+    logging.debug(f"  - an exception occurred when uploading")
+    
diff --git a/enviro/html/provision-step-4-destination.html b/enviro/html/provision-step-4-destination.html
index afacdc4..a5451e5 100644
--- a/enviro/html/provision-step-4-destination.html
+++ b/enviro/html/provision-step-4-destination.html
@@ -47,6 +47,7 @@ <h2>Enter your username and password.</h2>
         <fieldset>
           <input type="text" name="mqtt_broker_username" value="{{config.mqtt_broker_username}}" placeholder="Username (e.g. data_junkie)" autocapitalize="none" autocorrect="off" autocomplete="off" spellcheck="false" />
           <input type="text" name="mqtt_broker_password" value="{{config.mqtt_broker_password}}" placeholder="Password (e.g. ih3artd4ta)" autocapitalize="none" autocorrect="off" autocomplete="off" spellcheck="false" />
+          <input type="checkbox" name="hass_discovery" value="{{config.hass_discovery}}" />
         </fieldset>
       </div>
 
diff --git a/enviro/provisioning.py b/enviro/provisioning.py
index 1baaef2..4049500 100644
--- a/enviro/provisioning.py
+++ b/enviro/provisioning.py
@@ -113,6 +113,7 @@ def provision_step_4_destination(request):
     config.mqtt_broker_address = request.form["mqtt_broker_address"]
     config.mqtt_broker_username = request.form["mqtt_broker_username"]
     config.mqtt_broker_password = request.form["mqtt_broker_password"]
+    config.hass_discovery = request.form["hass_discovery"]
 
     # adafruit io
     config.adafruit_io_username = request.form["adafruit_io_username"]
diff --git a/main.py b/main.py
index 95eff3b..7ec91e8 100644
--- a/main.py
+++ b/main.py
@@ -65,6 +65,11 @@
   filesystem_stats = os.statvfs(".")
   enviro.logging.debug(f"> {filesystem_stats[3]} blocks free out of {filesystem_stats[2]}")
 
+  # Add HASS Discovery command before taking new readings
+  if enviro.config.destination == "mqtt":
+      if enviro.config.hass_discovery:
+        enviro.hass_discovery()
+
   # TODO should the board auto take a reading when the timer has been set, or wait for the time?
   # take a reading from the onboard sensors
   enviro.logging.debug(f"> taking new reading")