I am running an infinte while loop. Inside the while loop i give a FOR loop which runs 3 times. each time i get a specific value of second from the real time clock. I need to store these 3 seconds value in an array and calculate the average at the end of 3 rd loop.
I tried like this:
int time_diff[3];// Initialization of array for 3 values double avg; SCU_APBPeriphClockConfig(__RTC,ENABLE); /*enable RTC clock*/ SCU_APBPeriphReset(__RTC,DISABLE); /*RTC out of RESET state*/ time.milliseconds = 0; // Initialization time sturcture while(1) { for(k=0;k<=2;k++) { if ( a condition) { RTC_GetTime(BINARY,&BEGIN_TIME); } if ( another conditon) { RTC_GetTime(BINARY,&END_TIME); time_diff[k] = %02dms; // THIS LINEDIDNT WORK. DONT KNOW how to save that current value to time_diff[k] array } if (k == 3) { avg = (time_diff[0]+ time_diff[1]+time_diff[2])/3; sprintf(text, "Average = %d",avg); lcd_print (text); } } }
How is it possible to save the millisecond value as an array element? This code below displays the millisecond. But what i need is to save this current value to an array and then do averaging.
sprintf(text, "TIME in milli: %02dms ",END_TIME.milliseconds); lcd_print (text);
This is basic 'C' language stuff - nothing specifically to do with ARM or Keil or embedded.
Some basic resource links listed here: blog.antronics.co.uk/.../
time_diff[k] = %02dms; // THIS LINEDIDNT WORK
What, exactly, did you expect it to do...?
I expected to store the current value from END_TIME.milliseconds to that array
How did you expect it to do that?
The line
time_diff[k] = %02dms;
doesn't even contain END_TIME.milliseconds
What part(s) of your 'C' text book(s) suggested that it was an appropriate expression to fulfil your requirement?
Note that you don't even need to store the individual samples to compute an average.
It's enough to sum the values and to sum the number of samples added to the sum.
for (;;) { ... sum += delta_t; count++; } avg = sum/count;
Without an array, you can sum many values - the limit is just when sum or count overflows.
thnx Westermark.
I used a if statement to break the whole program when the count is <=3. So it will count only for 3 times and then the whole is again reset. So i guess there will not be any overflow problem.