Decrementing value on LED segments

Question

i'm writing a code for a number on a led segement to decrease by 1 every five seconds

my actual code at the moment is this

FiveSecDelay+=1;
if (FiveSecDelay ==100)
{
    count2--; //decrement count2

    for (uint32_t x = 0; x < 4; x++) //split count to to individual digits
    {
        new_value[x] = count2 % 10;
        count2 = count2 / 10;
    }

    for (uint32_t i = 0; i < 4; i++)
    {
        Segment_Write(Digit[i],new_value[i]); assign  value to segments
    }
    FiveSecDelay =0;
}

I m using a scheduler to call a function every millisecond, in theory this supposed to work as i used the same technique to assign a value to the segments, what happens is that i have a starting value of 8, and it supposed to got 7,6,5,4 and so on till 0, but for some reason it goes from 8 to 42 and stays there

I had tried to fix it but have come up short.

"for some reason it goes from 8 to 42" It's trying to tell you the answer to the ultimate question. Now all you need to do is write a program that can tell you the question. — Mark Byers, Jul 17 '12 at 17:26
Didn't you ask a question very much like this one yesterday EDIT: You did. Is there some reason those answers don't work? http://stackoverflow.com/questions/11512918/is-there-a-way-you-can-decrement-an-array-in-a-periodic-fashion-in-c — Wug, Jul 17 '12 at 17:29
Wug , no those answers didnt work, for the life of me i dont know why — user1175889, Jul 17 '12 at 17:33
There are probably more errors in your code. Maybe the other errors are in the code you haven't posted. — Mark Byers, Jul 17 '12 at 17:34

score 0 · Answer 1 · answered Jul 17 '12 at 17:27

0

You alter the value of count2 in this line:

count2 = count2 / 10;

And I get the impression from what you've described that count2 is what is supposed to be going from 8 to 7 to ... to 0.

answered Jul 17 '12 at 17:27

jrad

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score 0 · Answer 2 · answered Jul 17 '12 at 17:28

You aren't just decrementing count2 every 5 seconds, you're dividing it by 10 repeatedly as well. You'll want a temporary variable:

int temp_count = count2;   // Or whatever type count2 is
for (unit32_t x = 0; x < 4; x++)
{
    new_value[x] = temp_count % 10;
    temp_count /= 10;
}

David G · Answer 3 · 2012-07-17T17:53:00.677

0

I would rewrite the main loop like this:

for(uint32_t div10=1,i=0;i<4;i++,div10*=10)
   Segment_Write(Digit[i],(count2%(10*div10))/div10);

Only one loop and only one auxiliary other than the loop counter (div10).

edited Jul 17 '12 at 17:53

answered Jul 17 '12 at 17:44

David G

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Decrementing value on LED segments

3 Answers3