Trouble with Interrupt and Timer. Anyone see the problem? Here is the code.

[lhatch]

Not sure if the PS is the problem, I pulled the commands from the GCBasic pdf file.

#chip 12F675, 4
#config osc = int

#define LED GPIO.4
Dir LED Out
Dim count as byte

  InitTimer1 Osc, PS1_1/8
  On Interrupt Timer1Overflow Call IncCounter
  IntON

    count = 0
do

    wait 1 h

loop

end

'#########################################
'# Sub routines and functions
'#########################################

Sub IncCounter
    count ++
    if count < 100 then
       Set LED ON
    else
        if count <200 then
           set LED OFF
        else
           count = 0
        end if
    end if
End Sub

[kent_twt4]

Hard to tell with the formatting, but need hashtags for #chip, #config, #define. Try using four "~~~~" before and after code, with a blank line before and after the ~'s.

Not tested, but you could try a different way of toggling the led in the sub incCounter:

sub incCounter
   if counter = 255 then led = ! led
end sub

[Chuck Hellebuyck]

What is it doing or not doing?
Seems like the LED should flash at a roughly 1 minute rate (52 seconds).

4 MHz/4 = 1 MHz instruction clock that feeds timer1 prescaler
1:8 prescaler makes timer1 clock 125 kHz
(1/125 kHz) * 65535 16 bit timer1 = 0.524 seconds per overflow
0.524 * 100 count variable increments = 52 seconds to change LED state.

Is this not happening?

[Marcoos]

if I understand what you want to do there are logical errors in the interrupt routine.
see if this can help you
Ciao

'# Sub routines and functions
'#########################################

Sub IncCounter
count ++
if count < 100 then
Set LED ON
else
if count >100 & <200 then
set LED OFF
else
count = 0
end if
end if
End Sub
[/code]

[lhatch]

@Chuck. I get no LED on at all. I I do a simple wait 1 s, set LED on, wait 1 s, set LED off, works fine. So not the hardware.

I don't see a logic problem with the LED toggle code, looks logical me too. Count is set to 0, interrupt fires and incs it to 1, that is less than 100 (so is 0), set LED ON should run. So I would think it would pop right on.

@Chuck, thanks for the info, was not 100% on the PS, now I am. I had thought maybe it was so fast I could not see it blink. Not the case. I also tried <10 and <20 to see if that was it before posting.

Anyway. Still no LED blinking, I want to make the a part of all my new projects, and I could make a state machine as well.

I will try Kent's toggle for grins, but my logic is fine far as I can see. Maybe I will look at the ASM too.

Thanks for any other ideas in advance.

[lhatch]

@kent_twt4 The toggle threw an error about GPIO and being defined.

[kent_twt4]

Oh well, worth a try. This works on a 12f683, not a whole lot in code savings though:

toggle = 1
...
...
...
sub IncCounter
count += 1
If count = 5 Then
    count = 0
    LED = toggle.0
    comf toggle,f    'invert toggle and save to register
End If
end sub

[Chuck Hellebuyck]

I built the program and ran the assembly file in MPLAB to simulate it.
The timer wasn't runnning.

Then I realized you never started it in the code.
You need to add the line:

StartTimer 1

I put it right after the IntON instruction and it ran fine in the simulator.

InitTimer1 Osc, PS1_1/8
On Interrupt Timer1Overflow Call IncCounter
IntON
StartTimer 1

[lhatch]

Thanks Chuck, original code and your starttimer and it's blinking now.

With 4 and 8 for the counts, not 100 and 200.

I saw the sample in the help file (or PDF) and did not see the starttimer 1. Once again, thank you very much.

How did you get MPASM to simulate it? I could not compile the ASM (wrong assembler I guess) and it would not load the .HEX file. Whats the secret or a link to it? I looked to see if I could change the assembler and did not see it.