diff --git a/daq.c b/daq.c
index 01e2d2a..94ac048 100644
--- a/daq.c
+++ b/daq.c
@@ -29,9 +29,9 @@
 
 int sensConf(unsigned char uartNumber, int baudRate, unsigned char mode[], unsigned char response[], int tries);
 int measure(unsigned char uartNumber, unsigned char command[], int multiplier, int excess);
-char *gmeasures(char src[], char fval, int nchar
-int str2int(unsigned char *ptr
-int DAQ(int t_hrs, int tm_s
+char *gmeasures(char src[], char fval, int nchar);
+int str2int(unsigned char *ptr);
+int DAQ(int t_hrs, int sp_s);
 
 int main(int argc, char *argv[]){
 
@@ -127,7 +127,7 @@ int str2int(unsigned char *ptr){
   return number;
 }
 
-int DAQ(int t_hrs, int tm_s)
+int DAQ(int t_hrs, int sp_s)
 {
   FILE* dfp;                                    // create a file pointer
   const char colums[200] = "t(s)\tCO2 uf(ppm)\tCO2(ppm)\tCO uf(ppm)\t"\
@@ -141,9 +141,9 @@ int DAQ(int t_hrs, int tm_s)
               co2_relH[10]="", DATA[100]="";    //measurements varirables
   time_t curtime;                               //current time (date)
   clock_t start_t, end_t;                       //processing time measurements variables
-  time_t next_samp_time;                        //time control variables
-	double tm_ms = tm_s*1e6 - 0.20e6;             //tiempo de muestreo en milisegundos (-) margen
-	double dif = tm_ms;                           //diferencia de tiempo(time to sleep)
+  time_t next_samp_time, t0;                    //time control variables
+	double iteration_time_ms = sp_s*1e6 - 0.2e6;  //cicle iteration maximum time
+	double inactivity_time = 1;                   //time to sleep
 
   time(&curtime);                               //saving date in curtime
   //registro datos de inicio
@@ -153,21 +153,25 @@ int DAQ(int t_hrs, int tm_s)
   fclose(dfp);                                  // close the file using the file pointer
   printf("%s", colums);                         //display variables colums
   //ciclo
-  next_samp_time = time(NULL) + tm_s;           //setting nex sampling time
-  for(int t = 0; t < (t_hrs*3600); t+=tm_s){    //cycle from 0 to adquisition time (seconds), incrementing sampling period
-    //checking if there's time to sleep
-    if (dif <= 0) printf("Ejecution time exceded.\n%s", colums);
-    else usleep((int)dif);                      //inactivity time
-    //waiting to start measurements
-    while(next_samp_time != time(NULL));
+  next_samp_time = time(NULL)+1;              //setting next sampling time
+  t0 = next_samp_time;                          //saving initial time
+  for(time_t t = 0; t < (t_hrs*3600); t+=sp_s){    //cycle from 0 to adquisition time (seconds), incrementing sampling period
+    //checking inactivity time
+    if (inactivity_time <= 1){
+      usleep((int)inactivity_time);             //inactivity
+    }
+    else{
+      printf("Ejecution time exceded.\n%s", colums);
+      next_samp_time = time(NULL)+1;              //updating time values
+      t = next_samp_time-t0;
+    }
+    while(next_samp_time != time(NULL));      //synchronizing/waiting to start measurements
 
     start_t = clock();                          //saving start time
-      //transmiting commands to sensors
-      uartTransmit(COAF, get_readigns);
+      uartTransmit(COAF, get_readigns);         //transmiting commands to sensors
       uartTransmit(LuminOX, Readings_OX);
       uartTransmit(SprintIR, get_readigns
-      //receiving replys from
-      uartReceive(COAF);
+      uartReceive(COAF);                        //receiving replys from
       uartReceive(LuminOX);
       uartReceive(SprintIR);
       //interpreting and spliting measurements in variables
@@ -185,17 +189,17 @@ int DAQ(int t_hrs, int tm_s)
       //saving formated measurements in string DATA
       sprintf(DATA,
               "%d\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s",
-              t, co2_uf, co2_f, co_uf, co_f, o2_ppm, o2_xcent,
+              (int)t, co2_uf, co2_f, co_uf, co_f, o2_ppm, o2_xcent,
               co2_temp, o2_temp, co2_press, o2_press, co2_relH);
       printf("\r%s", DATA);                     //showing measurements on display
 
       dfp = fopen(data_file_path, "a");         // open file for writing
-          fprintf(dfp, "%s\n", DATA);           // saving measurements string to data file
+      fprintf(dfp, "%s\n", DATA);               // saving measurements string to data file
       fclose(dfp);                              // close the file using the file pointer
-      next_samp_time += tm_s;                         //adding sampling period to next_samp_time
+      next_samp_time += sp_s;                   //adding sampling period to next_samp_time
     end_t = clock();                            //saving end time
     //calculate time to sleep
-    dif =  tm_ms - ((double)(end_t - start_t)*1e6 / CLOCKS_PER_SEC);
+    inactivity_time =  iteration_time_ms - ((double)(end_t - start_t)*1e6 / CLOCKS_PER_SEC);
   }
 
   return 0;