diff --git a/essai.c b/essai.c
index 10d0eec..b17a131 100644
--- a/essai.c
+++ b/essai.c
@@ -121,7 +121,7 @@ nonl();         cbreak();       noecho();
 keypad(stdscr, TRUE);           /* acces aux touches 'curseur' */
 fond_ecran(" Demonstrator ");
 
-affiche_valeurs(serial_in, 5000000);
+affiche_valeurs(serial_in, 50000000);
 
 /*
  *      plop, on a fini, il faut restaurer la console
diff --git a/serial/t.c b/serial/t.c
index 3eef5fe..7d69f5b 100644
--- a/serial/t.c
+++ b/serial/t.c
@@ -18,16 +18,51 @@
 
 int	verbosity;
 
+
 /* ---------------------------------------------------------------- */
+int read_temps(char *buff, int k)
+{
+float		datas[4];
+int		raw[4], foo;
+long		temps;
+
+foo = parse4_Ivalues(buff, 'T', raw);
+	// 
+if (foo >= 0) {
+	temps = time(NULL);
+	values2temperature(raw, datas);
+	printf("%ld %f %f %f %f\n", temps,
+			datas[0], datas[1], datas[2], datas[3]);
+	fflush(stdout);
+	}
+else	{
+	fprintf(stderr, "%s: parse -> %d\n", __func__, foo);
+	}
+
+return 0;
+}
+/* ---------------------------------------------------------------- */
+int read_light(char *buff, int k)
+{
+int		val;
+
+if (1 == sscanf(buff+1, "%d", &val)) {
+	printf("--------- %04X ----------\n", val);
+	return 0;
+	}
+return -3;
+}
+/* ---------------------------------------------------------------- */
+
 int loop(int sfd, int iters)
 {
 int		count, foo;
 long		temps;
 char		ligne[200], buff[200];
-float		datas[4];
 struct tm       *p_tms;
 
 for (count=0; count<iters; count++) {
+	//
 	foo = getline_to(sfd, ligne, 100, 0);
 	//
 	if (verbosity) {
@@ -42,19 +77,29 @@ for (count=0; count<iters; count++) {
 		(void)strftime(buff, 19, "%H:%M:%S", p_tms);
 		fprintf(stderr, "%s    %6d / %d\n", buff, count, iters);
 		}
-	//
-	foo = parse4values(ligne, 'T', datas);
-	// 
-	if (foo >= 0) {
-		temps = time(NULL);
-		values2temperature(datas);
-		printf("%ld %f %f %f %f\n", temps,
-				datas[0], datas[1], datas[2], datas[3]);
-		fflush(stdout);
+
+	foo = 0;
+	switch (ligne[0]) {
+		case 'L':
+			foo = read_light(ligne, 0);
+			break;
+		case 'T':
+			foo = read_temps(ligne, 0);
+			break;
+
+		default:
+			fprintf(stderr, "*** WTF '%s' ?\n", ligne);
+			foo = -1;
+			break;
+			
 		}
-	else	{
-		fprintf(stderr, "%s: parse -> %d\n", __func__, foo);
+		
+	if (foo) {
+		fprintf(stderr, "%s : error %d after switch\n",
+					__func__, foo);
 		}
+	if (verbosity)		puts("");
+	
 	}
 return 0;
 }
diff --git a/simulator/rdtemp/rdtemp.ino b/simulator/rdtemp/rdtemp.ino
index 2e99aa5..e373bf1 100644
--- a/simulator/rdtemp/rdtemp.ino
+++ b/simulator/rdtemp/rdtemp.ino
@@ -24,9 +24,21 @@ void setup() {
   Serial.print("M running now\n");
   
 }
-/* -------------------------------------------------- */
 /* ================================================== */
-short adc_pins[] = { A0, A1, A2, A4 };
+/*
+ * the light captor is on A4 pin
+ */
+void readlight(void)
+{
+  short value;
+  delay(100);
+  value = analogRead(A4);
+  Serial.print("L ");
+  Serial.print(value);
+  Serial.print('\n');
+}
+/* ================================================== */
+short adc_pins[] = { A0, A1, A2, A3 };
 #define NB_PASSE  4
 /* -------------------------------------------------- */
 void updatevalues(short *ptr)
@@ -57,7 +69,7 @@ void sendvalues(short *ptr)
     Serial.print(" ");
     Serial.print(ptr[foo]);
     }
-  Serial.print("\n");
+  Serial.print('\n');
 }
 /* -------------------------------------------------- */
 void update_and_send(void)
@@ -66,12 +78,17 @@ void update_and_send(void)
   
   updatevalues(values);
   sendvalues(values);
-  
-  
+ 
 }
 /* ================================================== */
 void loop() {
+  static int foo = 0;
   update_and_send();
+
+  if (foo++ > 5) {
+    readlight();    foo = 0;
+  }
+ 
   delay(DELAI);
 }