CCP and timers to capture frequency

[richard]

my old proteus can't sim that chip but a 16f1825 is ok

done like this the "remainder" is time between pulses in uS provided overflow is < 2

'****************************************************************
'*  Name    : 324_CCP1_Test.pbp                                 *
'*  Date    : 09/30/20                                          *  
'*  Notes   : TEST  using    16F1825                            *
'****************************************************************
'*THIS REV:  timing perfect
#CONFIG
  __config  _CONFIG1, _FOSC_INTOSC & _WDTE_ON & _PWRTE_OFF & _MCLRE_ON & _CP_OFF & _CPD_OFF & _BOREN_ON & _CLKOUTEN_OFF & _IESO_ON & _FCMEN_ON
  __config  _CONFIG2, _WRT_OFF & _PLLEN_OFF & _STVREN_ON & _BORV_19 & _LVP_OFF
#ENDCONFIG

INCLUDE "DT_INTS-14.bas"  ; 
INCLUDE "ReEnterPBP.bas"    ; Include for DT_INTS.  ver 3.4

DEFINE OSC 8
PulseIn     var PORTC.5  ' Monitor ECM tachometer signal 
PulseFlag   var byte       ' register if CAPTURE Int was entered
Overflows   VAR word    ' count the times TMR1 overflows
Remainder   VAR word    ' remaining TMR1 ticks after last overflow
lastcount   VAR word
ANSELA = 0                  ' Set all digital 
ANSELC = 0
CCP1CON = %00000101     ' On, Capture every + edge

'CCPTMRS = %01010101     ' ALL CCPS using TMR1 (already default)
'INTCON = %11000001

OSCCON=$70


T1CON  = %00010001       ' 1:1 prescale, clock=Fosc/4, TMR1=on 
T2CON  = %00000100       ' 1:1 PRE and POST, ON 
'********* USART  ****************************************************
DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
DEFINE HSER_CLROERR 1 ' Clear overflow automatically
DEFINE HSER_SPBRG 51  ' 9600 Baud @ 8MHz, 0.16%
SPBRGH = 0
BAUDCON.3 = 1         ' Enable 16 bit baudrate generator

HSEROUT ["324_CCP1_test",10,13]
pause 2000
;----[Interrupts]----------------------------------------
ASM
INT_LIST  macro    ; IntSource,   Label,   Type, ResetFlag?
        INT_Handler   CCP1_INT, _Capture,   PBP,  yes        ; WORKS
        INT_Handler   TMR1_INT,  _Timer1,    PBP,  yes
    endm
    INT_CREATE               ; Creates the High Priority interrupt processor
ENDASM
@    INT_ENABLE  CCP1_INT    ; enable Capture interrupts
@    INT_ENABLE  TMR1_INT    ; enable Timer 1 interrupts


Main:
  IF PulseFlag = 1 THEN
'     PULSOUT tachdrv, 50      ' 
     HSEROUT ["OF= ",DEC Overflows,"  ,Ticks= ",DEC Remainder, 13,10]
     PulseFlag = 0
     Overflows = 0
     PIR1.0 = 0               ' clear TMR1IF
  ELSE 
    HSEROUT ["NoFlag", 13,10]  
  ENDIF 
GOTO Main
'---[CCP1 - interrupt handler]------------------------------------------
Capture:  ' Enter here with input Pulse  (CCP1) 
    Remainder= TMR1  - lastcount
    lastcount = TMR1
    PulseFlag = 1           ' set flag to pulse out @ each +capture
@ INT_RETURN
''**** TMR *********
Timer1:
    Overflows = Overflows + 1
@ INT_RETURN    
END