diff --git a/homecontrol-dash.py b/homecontrol-dash.py
index 0aa6f09..300955d 100755
--- a/homecontrol-dash.py
+++ b/homecontrol-dash.py
@@ -6,6 +6,7 @@ import dash_html_components as html
 from dash.dependencies import Input, Output
 import time
 import requests
+from math import log, log10
 
 URL_BASE="http://innocence:5000"
 
@@ -26,6 +27,7 @@ def get_values(sensorId, min_ts, max_ts, limit):
         try:
             url = "%s/sensor/get_values/%s?min_ts=%s&max_ts=%s&limit=%s" % (URL_BASE,
                     sensorId, min_ts, max_ts, limit)
+            # print(url)
             res = requests.get(url)
             ret = res.json()[sensorId]
         except Exception as ex:
@@ -91,56 +93,79 @@ app.layout = html.Div(children=[
     ]),
 ])
 
-
 @app.callback(
         [Output('slider-min', 'min'), Output('slider-min', 'value'),
-            Output('slider-max', 'min')],
+            Output('slider-min', 'max')],
         [Input('tabs-select-sensor', 'value')])
 def update_slider_min(sensorId):
     res = get_values(sensorId, 0, int(time.time()), 1)
     min_ts = 0
+    # default last 7 days
+    cur_ts = round(time.time() - (60*60*24*7))
+    max_ts = int(time.time())
     sensorType = None
     if "values" in res:
         min_ts = int(res["values"][0]["ts"])
         sensorType = res["sensorType"]
 
-    return min_ts, min_ts, min_ts
-
-
-@app.callback(
-        Output('slider-limit-txt', 'children'),
-        [Input('slider-limit', 'value')])
-def update_slider_limit(value):
-    return "Limit: %s" % (value if value > 0 else None)
+    # print("min: [%f [%f] %f]" % (min_ts, min_ts, max_ts))
+    return min_ts, cur_ts, max_ts
 
 
 @app.callback(
         Output('slider-min-txt', 'children'),
         [Input('slider-min', 'value')])
-def update_slider_min(value):
+def update_slider_min_txt(value):
     return "From: %s" % (time.strftime("%Y/%m/%d %H:%M", time.localtime(float(value))) if
             value > 0 else 0)
 
+@app.callback(
+        [Output('slider-max', 'min'), Output('slider-max', 'value'),
+            Output('slider-max', 'max')],
+        [Input('tabs-select-sensor', 'value')])
+def update_slider_max(sensorId):
+    res = get_values(sensorId, 0, int(time.time()), 1)
+    min_ts = 0
+    max_ts = int(time.time())
+    sensorType = None
+    if "values" in res:
+        min_ts = int(res["values"][0]["ts"])
+        sensorType = res["sensorType"]
+
+    # print("max: [%f [%f] %f]" % (min_ts, max_ts, max_ts))
+    return min_ts, max_ts, max_ts
+
 
 @app.callback(
         Output('slider-max-txt', 'children'),
         [Input('slider-max', 'value')])
-def update_slider_max(value):
+def update_slider_max_txt(value):
     return "To: %s" % (time.strftime("%Y/%m/%d %H:%M", time.localtime(float(value))))
 
 
 @app.callback(
-    [Output('graph-sensor-values', 'figure'), Output('slider-min', 'max'),
-        Output('slider-max', 'max')],
+        Output('slider-limit-txt', 'children'),
+        [Input('slider-limit', 'value')])
+def update_slider_limit_txt(value):
+    return "Limit: %s" % (value if value > 0 else None)
+
+
+@app.callback(
+    Output('graph-sensor-values', 'figure'),
     [Input('tabs-select-sensor', 'value'), Input('slider-min', 'value'),
         Input('slider-max', 'value'), Input('slider-limit', 'value')])
 def update_graph_sensor_values(sensorId, min_ts, max_ts, limit):
-    res = get_values(sensorId, min_ts, max_ts, limit)
+    res = {}
+    if min_ts > 0:
+        res = get_values(sensorId, min_ts, max_ts, limit)
     if "values" in res:
         v = res["values"]
         s = res["sensorType"]
         x = [time.strftime("%m%d-%H%M", time.localtime(float(v[i]["ts"]))) for i in range(len(v))]
-        y = [v[i]["value"] for i in range(len(v))]
+        if s == "luminance":
+            y = [log10(v[i]["value"]/5+1) for i in range(len(v))]
+        else:
+            y = [v[i]["value"] for i in range(len(v))]
     else:
         s = sensorId
         x = [0]
@@ -148,7 +173,7 @@ def update_graph_sensor_values(sensorId, min_ts, max_ts, limit):
     return {
         'data': [ {'x': x, 'y': y, 'mode': 'line', 'name': "%s" % (s)} ],
         'layout': { 'title': 'Data for sensor: %s (%d elements)' % (s, len(x)) }
-    }, time.time(), time.time()
+    }
 
 if __name__ == '__main__':