help with timer to make clock

[Nobody/Anonymous]

here is what i have, I left out the extra subs that are unrelated to the problem, it only sends out zero values and never increments the count.
#chip 12F683, 18
#config MCLRE=off, WDT=off
Ser_Init
on interrupt Timer1Overflow call IncCounter
dim serun as byte
dim serdec as byte
dim sercen as byte
dim sermil as byte
dim serdecimil as byte

InitTimer1 ExtOsc, PS1_8
dim full as byte
dim min as byte
dim sec as byte
dim hr as byte
full = 0
sec=0
min=0
hr=0
wait 1 s

ClearTimer 1
TMR1L = 0 'Need to do this according to the PIC datasheet
    TMR1H = 36
    TMR1L = 13 'should be 10hz
StartTimer 1

main:
if full = 10 then
sec=sec+1
full=0
end if 
if sec = 60 then
min= min+1
sec=0
end if
if min= 60 then
hr=hr+1
min=0
end if
if hr=25 then hr=0
bin2ascii (hr)
xmit_print (":")
bin2ascii (min)
xmit_print (":")
bin2ascii (sec)
wait 250 ms
xmit_rs232 12
xmit_rs232 13
goto main

Sub IncCounter
    TMR1L = 0
    TMR1H = 255
    TMR1L = 82
full=full+1
end sub

[Mauried]

The Main routine takes too long to run.
The interrupts will occur 10 times a second, which is every 100 ms
but the main routine takes 250 ms+ to run.
It will never see full get to 10.
Either get rid of the wait 250 ms line in the main routine , or reduce the interrupt rate so that the interrupts occur slower.
If you are trying to build a clock, why not simply interrupt once a second.

[Nobody/Anonymous]

i can't get get it down to 1hz speed, the lowest it will go is 8.xxhz

[gcha44]

1) You must place second , minutes and hours calculations in your Sub IncCounter :
     After full=full+1
    if full = 10 then
      sec=sec+1
      full=0
   end if 
  if sec = 60 then
    min= min+1
    sec=0
  end if
if min= 60 then
   hr=hr+1
   min=0
end if
if hr=25 then hr=0

because if your main program is too long because a too long data transmission your calculations aren't taken into account !
2) If loop is too long and PIC doesn't transmits anything , errors may be in differents subs as Ser_init ,xmit_print or     bin2ascii
GC

[Mauried]

Also, where is the clock for the PIC coming from.
There doesnt appear to be any clock definition in the code.
To make a clock that keeps time , you must use an external crystal
as the internal RC oscillator isnt stable enough.
Its only  1% accurate.

[mmotte]

how fast is your external osc running?
"#chip 12F683, 18    "
is it a  18 mhz crystal?

If your doing RTC things  a 32khz clock crystal is usually used.  Run on internal osc for the main.

Also where are you reseting the Timer1  ovrflow flag?

[Nobody/Anonymous]

I still only get "00:00:00" transmitted to the pc over and over never incriments?
here is the whole code:
#chip 12F683, 18
#config MCLRE=off, WDT=off
Ser_Init
on interrupt Timer1Overflow call IncCounter
dim serun as byte
dim serdec as byte
dim sercen as byte
dim sermil as byte
dim serdecimil as byte

InitTimer1 ExtOsc, PS1_8
dim full as byte
dim min as byte
dim sec as byte
dim hr as byte
full = 0
sec=0
min=0
hr=0
wait 1 s

ClearTimer 1
TMR1L = 0 'Need to do this according to the PIC datasheet
    TMR1H = 36
    TMR1L = 13 'should be 10hz
StartTimer 1

main:

bin2ascii (hr)
xmit_print (":")
bin2ascii (min)
xmit_print (":")
bin2ascii (sec)
wait 10 ms
xmit_rs232 12
xmit_rs232 13
goto main

Sub IncCounter
ClearTimer 1
    TMR1L = 0
    TMR1H = 36
    TMR1L = 13
StartTimer 1
full=full+1
if full = 10 then
sec=sec+1
full=0
end if 
if sec = 60 then
min= min+1
sec=0
end if
if min= 60 then
hr=hr+1
min=0
end if
if hr=25 then hr=0
end sub

Sub Ser_Init
;slight adjustment was required for 9600bps delay value
#define baud 103 ;expressed as frequency in us
#define halfbaud 52 ;place Read of SerRx in middle of bit
#define SerTxHigh Set GPIO.0 On
#define SerTxLow Set GPIO.0 Off
#define SerRx GPIO.1
dir GPIO.0 out ;Tx
dir GPIO.1 in ;Rx
SerTxHigh ;Initial RS232 idle state
end sub

sub XMIT_PRINT (PrintData$)
PrintLen = PrintData(0)
if PrintLen = 0 then exit sub
'Write Data
for SysPrintTemp = 1 to PrintLen
XMIT_RS232(PrintData(SysPrintTemp))
next
end sub

Sub XMIT_RS232(Xmit_Byte)#NR
SerTxLow
wait baud us
For cntr = 1 to 8
Rotate Xmit_Byte Right
If Status.C ON Then SerTxHigh
If Status.C Off Then SerTxLow
wait baud us
Next
SerTxHigh
wait baud us
end sub

sub bin2ascii (LCDValue as word ) #NR
Dim SysCalcTempX As Word
LCDValueTemp = 0
LCDShowChar = 0
SERDECMIL = 0
SERMIL = 0
SERCEN = 0
SERDEC = 0
SERUN = 0

If LCDValue >= 10000 then
LCDValueTemp = LCDValue / 10000
LCDValue = SysCalcTempX
SERDECMIL = LCDValueTemp + 48
Xmit_RS232 (SERDECMIL)
LCDShowChar = TRUE
End If

If LCDShowChar > 0 or LCDValue >= 1000 then
LCDValueTemp = LCDValue / 1000
LCDValue = SysCalcTempX
SERMIL = LCDValueTemp + 48
Xmit_RS232 (SERMIL)
LCDShowChar = TRUE
End If

If LCDShowChar > 0 or LCDValue >= 100 then
LCDValueTemp = LCDValue / 100
LCDValue = SysCalcTempX
SERCEN = LCDValueTemp + 48
Xmit_RS232 (SERCEN)
LCDShowChar = TRUE
End If

'If LCDShowChar > 0 or LCDValue >= 10 then
LCDValueTemp = LCDValue / 10
LCDValue = SysCalcTempX
SERDEC = LCDValueTemp + 48
Xmit_RS232 (SERDEC)
'End If

SERUN = LCDValue + 48
Xmit_RS232 (SERUN)
End Sub

[Nobody/Anonymous]

In order to get glitch free output, I think the main program should also be in the isr (no wait states here).  Just output every sec (i.e. when "full " rolls over).  If the Uart routine is also going to be used in main then their will be glitches.

Kent

main:
goto main
Sub IncCounter
ClearTimer 1
    TMR1L = 0 
    TMR1H = 36
    TMR1L = 13
StartTimer 1
full=full+1
if full = 10 then 
sec=sec+1
full=0
end if  
if sec = 60 then 
min= min+1
sec=0
end if
if min= 60 then
hr=hr+1
min=0
end if
if hr=25 then hr=0
if full = 0 then
    if hr < 10 then xmit_print ("0")
    bin2ascii (hr)
    xmit_print (":")
    if min < 10 then xmit_print ("0")
    bin2ascii (min)
    xmit_print (":")
    if sec < 10 then xmit_print ("0")
    bin2ascii (sec)
    xmit_rs232 10
    xmit_rs232 13
end if
end sub

[Nobody/Anonymous]

so I made the changes you suggested above and have the following code, but i get no output at all, so my guess is the timer1 is not running and full is never reaching 10 and tx never happens.
#chip 12F683, 18
#config MCLRE=off, WDT=off
Ser_Init
on interrupt Timer1Overflow call IncCounter
dim serun as byte
dim serdec as byte
dim sercen as byte
dim sermil as byte
dim serdecimil as byte

InitTimer1 ExtOsc, PS1_8
dim full as byte
dim min as byte
dim sec as byte
dim hr as byte
full = 0
sec=0
min=0
hr=0
wait 1 s

ClearTimer 1
TMR1L = 0 'Need to do this according to the PIC datasheet
    TMR1H = 36
    TMR1L = 13 'should be 10hz
StartTimer 1

main:
goto main

Sub IncCounter
ClearTimer 1
TMR1L = 0
TMR1H = 36
TMR1L = 13
StartTimer 1
full=full+1
if full = 10 then
sec=sec+1
full=0
end if
if sec = 60 then
min= min+1
sec=0
end if
if min= 60 then
hr=hr+1
min=0
end if
if hr=25 then hr=0
if full = 0 then
'if hr < 10 then xmit_print ("0")
bin2ascii (hr)
xmit_print (":")
'if min < 10 then xmit_print ("0")
bin2ascii (min)
xmit_print (":")
'if sec < 10 then xmit_print ("0")
bin2ascii (sec)
xmit_rs232 10
xmit_rs232 13
end if
end sub

Sub Ser_Init
;slight adjustment was required for 9600bps delay value
#define baud 103 ;expressed as frequency in us
#define halfbaud 52 ;place Read of SerRx in middle of bit
#define SerTxHigh Set GPIO.0 On
#define SerTxLow Set GPIO.0 Off
#define SerRx GPIO.1
dir GPIO.0 out ;Tx
dir GPIO.1 in ;Rx
SerTxHigh ;Initial RS232 idle state
end sub

sub XMIT_PRINT (PrintData$)
PrintLen = PrintData(0)
if PrintLen = 0 then exit sub
'Write Data
for SysPrintTemp = 1 to PrintLen
XMIT_RS232(PrintData(SysPrintTemp))
next
end sub

Sub XMIT_RS232(Xmit_Byte)#NR
SerTxLow
wait baud us
For cntr = 1 to 8
Rotate Xmit_Byte Right
If Status.C ON Then SerTxHigh
If Status.C Off Then SerTxLow
wait baud us
Next
SerTxHigh
wait baud us
end sub

sub bin2ascii (LCDValue as word ) #NR
Dim SysCalcTempX As Word
LCDValueTemp = 0
LCDShowChar = 0
SERDECMIL = 0
SERMIL = 0
SERCEN = 0
SERDEC = 0
SERUN = 0

If LCDValue >= 10000 then
LCDValueTemp = LCDValue / 10000
LCDValue = SysCalcTempX
SERDECMIL = LCDValueTemp + 48
Xmit_RS232 (SERDECMIL)
LCDShowChar = TRUE
End If

If LCDShowChar > 0 or LCDValue >= 1000 then
LCDValueTemp = LCDValue / 1000
LCDValue = SysCalcTempX
SERMIL = LCDValueTemp + 48
Xmit_RS232 (SERMIL)
LCDShowChar = TRUE
End If

If LCDShowChar > 0 or LCDValue >= 100 then
LCDValueTemp = LCDValue / 100
LCDValue = SysCalcTempX
SERCEN = LCDValueTemp + 48
Xmit_RS232 (SERCEN)
LCDShowChar = TRUE
End If

'If LCDShowChar > 0 or LCDValue >= 10 then
LCDValueTemp = LCDValue / 10
LCDValue = SysCalcTempX
SERDEC = LCDValueTemp + 48
Xmit_RS232 (SERDEC)
'End If

SERUN = LCDValue + 48
Xmit_RS232 (SERUN)
End Sub

[Nobody/Anonymous]

Really should use the code tags.  Copy and pasting native text is in some sort of weird format, and doesn't seem to compile. 

You could try the internal 4Mhz osc as a test, just to see if there's output.

I became frustrated with the results from the TMR1 register, and interrupts.  Moved over to CCP1, in the software interrupt mode, so everything is Main now.  The results seem much better, although not great.  For an accurate clock I've used the ds1307 in the past.

Good luck.

Kent.

[Mauried]

Ive made several clocks using 16F88 with a low frequency clock crystal (2 Mhz)
which allows you to use a 1 hz tick interrupt to do the counting.
Ideally also, if you want to use a serial output for the data its best to use a chip
with a hardware uart, so that the interrupts dont glitch the output characters.
The timer overflow concept to interrupt should work ok as long as you keep the code within
the interrupt routine at a minimum.
There is a simple example that comes with the GCbasic install called interrupt that explains
how to use the timer overflow to count .

[Nobody/Anonymous]

I think you configured Timer1 to use external clock:

InitTimer1 ExtOsc, PS1_8

Exists that external clock??
That's not the clock you use for PIC, its a dedicated ext. clock, ussually 32.768 KHz for real time,  that should be connected to T1OSI and T1OSO pins.

If you want to use the same clock the cpu, then configure this way:
InitTimer1 Osc, PS1_8

[kent_twt4]

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