diff --git a/simulator/rdtemp/rdtemp.ino b/simulator/rdtemp/rdtemp.ino
index 6042e2f..3d7bc69 100644
--- a/simulator/rdtemp/rdtemp.ino
+++ b/simulator/rdtemp/rdtemp.ino
@@ -10,6 +10,7 @@
 void setup() {
   Serial.begin(9600);
   pinMode(LED_BUILTIN, OUTPUT);
+  
   Serial.print("\n");
   /* XXX */
   /*  changing the voltage reference of the ADC
@@ -28,10 +29,12 @@ short adc_pins[] = { A0, A1, A2, A4 };
 void updatevalues(short *ptr)
 {
   int foo;
+  digitalWrite(LED_BUILTIN, HIGH);
   for (foo=0; foo<NBVAL; foo++) {
     ptr[foo] = analogRead(adc_pins[foo]);
-   delay(200);
-   }
+    delay(200);
+    }
+  digitalWrite(LED_BUILTIN, LOW);
 }
 /* -------------------------------------------------- */
 void sendvalues(short *ptr)