random problem

Hello everyone,
I have a strange problem, I wrote a little program to control a VMUSIC2 MP3 player. It plays an MP3 with morse beeps that will then switch a lamp. The user can change the MP3 file without having to mess with the program.
After playing the file the player should wait between 0 and 45 minutes randomly before playing the morse code again.
All works okay but after a while the randomness disappears and it will always wait 45 minutes. Seems something wrong with the random command, maybe the seed? any help is appreciated. Here's the code:

Code:

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' 12-05-09 morse code player, reads mp3 file to control lamp

@ device  pic12F683, INTRC_OSC_NOCLKOUT, wdt_off, pwrt_on, mclr_off, protect_off

include "modedefs.bas"
define  OSC 4
                         
OSCCON    = %01100000      ' Set to 4MHz       
CMCON0    = %00000111            ' Analog comparators off       
ANSEL      = %00000010            ' Set AN1 as analog, rest digital           
TRISIO    = %00100010                             
GPIO      = %00010000      ' GPIO.4 hoog voor serieel, start anders niet

relay      var GPIO.0
led        var GPIO.2

counter    var word
temp        var word
time        var word
audio      var byte

pause 2000

loop:
    SerOut GPIO.4,T2400,["V3A",13]          ' play all songs
play_morse:
    toggle led
    adcin 1,audio
    if audio > 25 then                      ' test sound (more than 500 mV)
        high relay
    else
        low relay
    endif   
    SERIN2 GPIO.5,396,20,play_morse,[wait ("Stopped")]
    random temp
    time = temp/24                          ' between 0 and 45 seconds
    for counter = 1 to time
        pause 1000
        toggle led
    next counter
goto loop
   
End

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If you read the section on Random, you will see that your output variable is also used as the seed. Try to use Random Time instead of Random Temp. That way your seed is changed after each use. In your code Temp is unnecessary anyway.

I'm not so sure about that, if I use time as my seed it will always be smaller then 2730, (time / 24) Will this not affect the output of the random generator?
i.e. does the seed need to be a 16 bit number or not?

Okay, I did a little test:
If I try this code:

Code:

---

loop:
    random temp
    toggle LED
    pause temp >> 8
goto loop

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My LED flashes in a very nicely random way.

If I try this code:

Code:

---

loop:
    random temp
    temp = temp >> 8
    toggle LED
    pause temp
goto loop

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Then it does not flash in a nicely random way.
So... the seed must not be modified.
But anyway this still does not explain why my morse code flasher doesn't work. Unfortunately I do not have the circuit at hand (it's in Paris now) so have to probably build a second one to really test.

What about using your adcin 'audio' value as the seed - it seems like it should give you some randomness.

Hmm that's a good idea, will try, thanks