diff --git a/CAD/MiliOhmMeter/MiliOhmMeter-backups/MiliOhmMeter-2022-02-16_161814.zip b/CAD/MiliOhmMeter/MiliOhmMeter-backups/MiliOhmMeter-2022-02-16_161814.zip
deleted file mode 100644
index cf72810..0000000
Binary files a/CAD/MiliOhmMeter/MiliOhmMeter-backups/MiliOhmMeter-2022-02-16_161814.zip and /dev/null differ
diff --git a/CAD/MiliOhmMeter/MiliOhmMeter-backups/MiliOhmMeter-2022-09-23_144032.zip b/CAD/MiliOhmMeter/MiliOhmMeter-backups/MiliOhmMeter-2022-09-23_144032.zip
new file mode 100644
index 0000000..390e673
Binary files /dev/null and b/CAD/MiliOhmMeter/MiliOhmMeter-backups/MiliOhmMeter-2022-09-23_144032.zip differ
diff --git a/MilliOhmMeter_FW/src/display_buttons.cpp b/MilliOhmMeter_FW/src/display_buttons.cpp
index c805ce7..b45d251 100644
--- a/MilliOhmMeter_FW/src/display_buttons.cpp
+++ b/MilliOhmMeter_FW/src/display_buttons.cpp
@@ -89,6 +89,7 @@ void c_onScreenButton::handle()
   else if (_stateFn != NULL)
   {
     _state = _stateFn();
+    _displayState = _state;
   }
   log_d("item(%s)=%d",_name.c_str(), _state);
 }
diff --git a/MilliOhmMeter_FW/src/display_hall.h b/MilliOhmMeter_FW/src/display_hall.h
index b924e37..c83d7f8 100644
--- a/MilliOhmMeter_FW/src/display_hall.h
+++ b/MilliOhmMeter_FW/src/display_hall.h
@@ -14,6 +14,7 @@
 #define FONT8 u8g2_font_helvR08_tf
 #define FONT16 u8g2_font_7x14_tf
 #define FONT24 u8g2_font_freedoomr25_tn //u8g2_font_logisoso24_tf
+#define FONT25 u8g2_font_helvR24_tf
 
 class U8G2_SSD1322 : public U8G2 {
   public: 
diff --git a/MilliOhmMeter_FW/src/measure.cpp b/MilliOhmMeter_FW/src/measure.cpp
index 05f5c43..679fe15 100644
--- a/MilliOhmMeter_FW/src/measure.cpp
+++ b/MilliOhmMeter_FW/src/measure.cpp
@@ -43,6 +43,23 @@ float getValue(void)
   return getMeasurement();
 }
 
+
+String getErrorString()
+{
+  if(getOpenState())
+  {
+    return "OPEN";
+  }
+  else if(getValue() < 0)
+  {
+    return "POL";
+  }
+  else
+  {
+    return "";
+  }
+}
+
 void clearStats(void)
 {
   clearAverages();
diff --git a/MilliOhmMeter_FW/src/measure.h b/MilliOhmMeter_FW/src/measure.h
index 35c8012..5529c7e 100644
--- a/MilliOhmMeter_FW/src/measure.h
+++ b/MilliOhmMeter_FW/src/measure.h
@@ -19,5 +19,6 @@ double getMax(void);
 double getRms(void);
 uint8_t getBar(void);
 float getValue(void);
+String getErrorString();
 void clearStats(void);
 
diff --git a/MilliOhmMeter_FW/src/measure_mode.cpp b/MilliOhmMeter_FW/src/measure_mode.cpp
index ddd7e87..67cd359 100644
--- a/MilliOhmMeter_FW/src/measure_mode.cpp
+++ b/MilliOhmMeter_FW/src/measure_mode.cpp
@@ -24,18 +24,40 @@ bool getErrorState(void)
 
 bool getOkState(void)
 {
+
   return measureOK;
 }
 
 bool getOpenState(void)
 {
-  if(getValue() > 3.2F)
+  if(getValue() > 2.4F)
   {
+    measureOK = false;
     return true;
   }
   return false;
 }
 
+bool getPolarity(void)
+{
+  if(getValue() < 0)
+  {
+    measureOK = false;
+    return true;
+  }
+  return false;
+}
+
+void setMeasurementOK()
+{
+  measureOK = true;
+}
+
+void setMeasuremoteNOK()
+{
+  measureOK = false;
+}
+
 void initMeasureMode(void)
 {
   log_i("init measure mode");
diff --git a/MilliOhmMeter_FW/src/measure_mode.h b/MilliOhmMeter_FW/src/measure_mode.h
index ba05084..6004a6d 100644
--- a/MilliOhmMeter_FW/src/measure_mode.h
+++ b/MilliOhmMeter_FW/src/measure_mode.h
@@ -12,6 +12,8 @@ void setMeasureMode(e_measureMode newMode);
 bool getErrorState(void);
 bool getOkState(void);
 bool getOpenState(void);
-
+bool getPolarity(void);
+void setMeasurementOK();
+void setMeasurementNOK();
 void initMeasureMode(void);
 void handleMeasureMode(void);
\ No newline at end of file
diff --git a/MilliOhmMeter_FW/src/screen_main.cpp b/MilliOhmMeter_FW/src/screen_main.cpp
index 3f6d23a..49f2bdc 100644
--- a/MilliOhmMeter_FW/src/screen_main.cpp
+++ b/MilliOhmMeter_FW/src/screen_main.cpp
@@ -61,10 +61,10 @@ c_onScreenButton ma200("200m", mA200, LocBottom, BUTTON2, &button2);
 c_onScreenButton ma1000("1A", mA1000, LocBottom, BUTTON3, &button3);
 c_onScreenButton mauto("Reset", 4, LocBottom, BUTTON4, &button4);
 c_onScreenButton bsetup("Conf", 5, LocBottom, BUTTON5, &button5);
-c_onScreenButton errorState("ER", 6, LocRight, &getErrorState);
+c_onScreenButton errorState("", 6, LocRight, NULL);
 c_onScreenButton okState("OK", 7, LocRight, &getOkState);
 c_onScreenButton openState("Open", 8, LocRight, &getOpenState);
-c_onScreenButton wifiState("Wifi", 9, LocRight, &getWifiState);
+c_onScreenButton polState("Pol", 9, LocRight, &getPolarity);
 
 void screenMainSetWarning(bool warning)
 {
@@ -101,7 +101,7 @@ void initDisplayMain(void)
   mainScreen.addItem(&errorState);
   mainScreen.addItem(&okState);
   mainScreen.addItem(&openState);
-  mainScreen.addItem(&wifiState);
+  mainScreen.addItem(&polState);
 
   mainScreen.begin();
 
@@ -116,18 +116,31 @@ void screenMainDrawLayout(void)
   float rate = getSampleRate();
   getDisplay()->setCursor(5, 8);
   getDisplay()->printf("Fs:%4.0fHz", rate);
-  getDisplay()->setCursor(170, 8);
-  getDisplay()->printf("loop=%dms", timer);
+  // getDisplay()->setCursor(170, 8);
+  // getDisplay()->printf("loop=%dms", timer);
 }
 
 void ScreenMainDrawValues(void)
 {
   getDisplay()->setFont(FONT24);
   getDisplay()->setCursor(60, 45);
-  getDisplay()->printf("%4.3f", getValue());
-  uint16_t stringwidth = getDisplay()->getStrWidth(drawValue("", getValue(), "").c_str());
-  getDisplay()->setFont(u8g2_font_8x13_t_symbols);
-  getDisplay()->drawUTF8(78 + stringwidth + 4, 43, "Ω");
+  String errorstr = getErrorString();
+  
+  if(errorstr == "")
+  {
+    setMeasurementOK();
+    getDisplay()->printf("%4.3f", getValue());
+    uint16_t stringwidth = getDisplay()->getStrWidth(drawValue("", getValue(), "").c_str());
+    getDisplay()->setFont(u8g2_font_8x13_t_symbols);
+    getDisplay()->drawUTF8(70 + stringwidth + 10, 43, "Ω");
+  }
+  else
+  {
+    getDisplay()->setFont(FONT25);
+    log_d("get errorstring: %s",errorstr);
+    getDisplay()->printf("%s", errorstr.c_str());
+  }
+
   getDisplay()->setFont(FONT8);
   // getDisplay()->drawUTF8(60 + stringwidth + 3, 43, "v");