> -----Messaggio originale-----
> Da: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]Per conto di Mike Keitz
> Inviato: giovedl 31 dicembre 1998 20.29
> A: PICLIST@MITVMA.MIT.EDU
> Oggetto: Re: compact sort program
>
>
> On Thu, 31 Dec 1998 18:08:30 +0100 Gianni <gia.ma.fra@IOL.IT> writes:
> >Hi!
> >I have written a program for a PIC16F84 that emulate a motorized 2 cam
> >programmable daily timer.
> >I keep in PIC's eeprom the setpoint (20 max) in the following
> >24h BCD format 1)byte HH  2)byte mm  3)byte which bit I want to
> >set/reset .
> >Every minute I compare the actual time with the setpoint and if time
> >is >=
> >setpoint I copy the third byte in a buffer then repaet for next
> >setpoint.
>
> >At the end of eeprom , I copy the buffer to the out port .
> >This works properly only if setpoint (HH:mm) are in ascending order.
>
> It seems like it would work no matter what the order is, if you check all
> the setpoints every minute.  The only conflict would be if two or more
> setpoints are telling the same output to go opposite ways the same
> minute.  In that case, the last one in the table would dominate.
>
        Suppose it's 12:10 and I have in eeprom the following setpoints :
                SET time        mode            comparison result
                05:30           ON              ON      (if actual time>=SET the
n
                08:00           OFF             OFF       buffer=mode
                11:15           ON              ON       else
                19:00           OFF             Skip     end if )
        and the buffer at the exit of routine is correct.
        Now I add a setpoint in the eeprom after the the last one
                03:18           ON              ON
                05:00           OFF             OFF
        and the buffer has a wrong result ; the last win.
        To get correct result I must keep the table in order or make a
        different kind of comparison ?

> >Unfortunately I have only 27 bytes of code free and 25 of ram.
>
> If I were writing this (in assembler), I can't imagine the time-keeping
> and setpoint-checking parts of the program needing more than 100 or so
> code locations.  The rest of the space could be used by the likely much
> more complicated code to provide a user interface to set the setpoints.

        In fact all the code is used for handling LCD display,
        IIC real-time clock,two button input device,and some text string
        for the menu.

> It may be time to review the situation and re-write your program
> entirely.  Most of my projects go through at least one such total
> rewrite.
>
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