ISO RTC pulse counter

[Reginald Neale]

Newbie ISO of code for implementation of a counter for one-second pulses, to trigger separate interrupts for each quarter hour, e.g. 900/1800/2700.3600 pulses.

[Anobium]

@Reginald. Is this a question?

[stan cartwright]

You could use the millis function. Untested code for 4 events. Just 15 minutes shown tim1 shown but same idea for tim2, etc.

#include millis.h
dim tim1,tim1event,tim2 etc as long
tim1event=15 * 60 * 1000  ;15 minutes... 900000 ms
tim1=mills
tim2=mills
tim3=mills
tim4=mills
do
if millis-tim1=tim1event then sub tim1go
loop
sub tim1go
code
end sub

[stan cartwright]

Using 1ms interrupt it could be for EVERY 15 minutes that uses same code every 15 minutes.

dim millis,tim1event as long
tim1event=15 * 60 * 1000 ;15 minutes... 900000 ms
millis=0
start 1ms interrupt isr
do
if millis=tim1event then sub tim1go
loop
;
sub tim1go
code
millis=0
end sub
;
sub isr
millis=millis + 1
end sub

[Anobium]

@Reggie

What do you mean by an ISO code for implemention?

[kent_twt4]

ISO, in search of?

Here is some setup code for an interrupt on pin change, using the 1 seconcd square wave output of Dallas DS1307. I was looking to take readings every 10 sec with this example

'*****setup IOC on RA7 with pullup*****
#define SqWaveIn PortA.7    'DS1307 1Hz Square Wave Out
Dir SqWaveIn In
'wait to enable IOCIE until after startlog button press
SET IOCAP7 ON
...
...
Set IOCIE On
'start logging right away
OneSecINT = 10
StartConv = True
Main:
  Do While StopLog = False
    If OneSecINT = 10 Then
      OneSecINT = 0
...
...

sub Interrupt
'1Hz Square Wave Out DS1307 Event Scheduler*******
  If IOCAF7 = 1 Then
    set IOCAF7 Off
    OneSecINT += 1
    'PulseOut Led, 5 ms
  End If
end sub

[Reginald Neale]

Thanks Kent. This seems closest to what I'm trying to do.

[Chris Roper]

If you want an RTC this version based on the millis() function may point you in the right direction:

'
' SoftRTC based on the Millis() interrupt
'
#chip 16f18855            ' Declare the Target Processor
#option explicit          ' Require Explicit declaration of Variables
#include <millis.h>       ' Include the Library

' declare working variables
  Dim SoftRTC_CurMs, SoftRTC_LstMs as word
  SoftRTC_LstMs = 0
  SoftRTC_CurMs = 0

  Dim SoftRTC_Hrs, SoftRTC_Min, SoftRTC_Sec as Byte

' Main
  Do
    SoftRTC_CurMs = millis()

    if SoftRTC_CurMs - SoftRTC_LstMs > 999 then  ' required Time has Elapsed
       SoftRTC_LstMs = SoftRTC_CurMs               ' Record Toggle Time
       SoftRTC_Update
    end if

  Loop

END

Macro SoftRTC_Update
  SoftRTC_Sec += 1
  if SoftRTC_Sec > 59 then
     SoftRTC_Sec = 0
     SoftRTC_Min += 1
  end if
  if SoftRTC_Min > 59 then
     SoftRTC_Min = 0
     SoftRTC_Hrs += 1
  end if
  if SoftRTC_Hrs > 23 then SoftRTC_Hrs = 0
End Macro

Millis() is device independent and uses Timer0 to generate an interrupt every millisecond.
the millis() function returns the total time in mS since the last reset.

The above code converts that elapsed time into an RTC with:
SoftRTC_Hrs : SoftRTC_Min : SoftRTC_Sec
containing the current elapsed time.

User code would be needed to set the initial time and handle alarm events etc.

This is just the basic framework but should work on any device supported by GCBASIC.

Hope it helps.

Cheers
Chris

[Chris Roper]

A striped down version of the SoftRTC code above may do the trick if I understand the initial question.

This code will call a user Subroutine every 15 Min:

'
'  15 MIn repeating alarm based on  Millis() interrupt
'
#chip 16f18855            ' Declare the Target Processor and Speed
#option explicit          ' Require Explicit declaration of Variables
#include <millis.h>       ' Include the Library

' declare working variables
  Dim SoftRTC_CurMs, SoftRTC_LstMs, SoftRTC_Sec  as word  
  SoftRTC_LstMs = 0
  SoftRTC_CurMs = 0
  SoftRTC_Sec  = 0

' Main                    
  Do
    SoftRTC_CurMs = millis()

    if SoftRTC_CurMs - SoftRTC_LstMs > 999 then
       SoftRTC_LstMs = SoftRTC_CurMs              
       SoftRTC_Sec += 1
       If SoftRTC_Sec > 899 then 
         SoftRTC_Sec = 0
         DoUserCode
       end if 
    end if

  Loop

END

Macro DoUserCode
    ' Code that runs evert 15 min
  ' may be a macro, sub or function
End Macro

Cheers
Chris

[stan cartwright]

original post for 1 second pulses.
not much code

#chip mega328p,16
#option Explicit
dir portc.2 out
dim millis,tim1event as long
tim1event=1000 ;every second
millis=0
;start 1ms interrupt isr
    On Interrupt Timer0Match1 Call isr
    Dim OCR0  AS byte alias OCR0A
    Dim TCCR0 AS  byte alias TCCR0B
    WGM01 = 1
    OCR0 = 62 ;1ms
    TCCR0 = 0x28
    TCCR0 = TCCR0 or 0x03
'---------------
do
  if millis=tim1event then tim1go
loop
;
sub tim1go ;every second
portc.2 = not portc.2
millis=0
end sub
;
sub isr
millis=millis + 1
end sub