Code:
' [ Program Description ]
' This Program is for a PIC18F4550 & was tested in an EasyPic6 board. *
' Purpose: *
' 1) Monitors 1/min interrupt from external Real Time Clock *
' [ Device Declaration
; if you un-comment these, you must comment the ones in the .inc file--
ASM ; 18F2550/4550, 8mhz crystal
__CONFIG _CONFIG1L, _PLLDIV_2_1L & _CPUDIV_OSC4_PLL6_1L & _USBDIV_2_1L
__CONFIG _CONFIG1H, _FOSC_HSPLL_HS_1H
__CONFIG _CONFIG2L, _PWRT_ON_2L & _BOR_OFF_2L & _VREGEN_ON_2L
__CONFIG _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
__CONFIG _CONFIG3H, _PBADEN_OFF_3H ; PortB resets as digital
__CONFIG _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L
ENDASM
Include "Modedefs.Bas"
INCLUDE "DT_INTS-18.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas" ' Include if using PBP high priority interrupts
INCLUDE "ALLDIGITAL.pbp" ' Sets all registers for digital ops.
DEFINE OSC 16
' Initialize Hardware
' =============
'Set registers
TRISA = 0 ' PORTA all outputs
TRISB =%00001100 ' RB2 & RB3 set as RTC Alarm1 & Alarm2 inputs
TRISC = 0
TRISD = 0
TRISE = 0
' Variables & Aliases for Pins other than RTC use
' ==================================
b0 VAR Byte ' LSB of range measurement when right justified
b1 VAR Byte ' MSB of range measurement when right justified
'SETUP FOR USING DS1337 Real Time Clock
' Setup Hardware for uart
' ==================
DEFINE HSER_BAUD 115200
DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h
DEFINE HSER_CLROERR 1
' * NOTES for use with EasyPic6 development board:
'For interface to DS1337 RTC:
' - To provide battery backup place a Shottky diode between + battery
' terminal and Vcc (pin-8) of the DS1337.
' - I2C communication lines should be connected to 4.7K pull-up resistors.
' - INTA & INTB lines should be connected to pull-up resistsors.
' - Turn off LEDs connected to I2C communication lines.
' Aliased Variables for CLock
' ====================
Alarm1 VAR PORTB.2 ' Alarm1 input from DS1337 INTA (pin-3)
Alarm2 VAR PORTB.3 ' Alarm2 input from DS1337 INTB (pin-7)
SCL VAR PORTB.1 ' I2C clock pin
SDA VAR PORTB.0 ' I2C data pin
RTCdevice CON %11010000 ' RTC device write address(byte addressing)
' A list of possible clock contrl settings, one which must be
' setup in the SetTimeAndDate subroutine.
'contrl CON %00000101 ' Starts oscillator, enables INTA interrupt
' from A1F, INTA/SQW off.
'contrl CON %00000110 ' Starts oscillator, enables INTB interrupt
' from A2F. WORKS OK!
' RTC Address definitions
' =================
SecReg CON $00 ' seconds address (00 - 59)
' MSB of SecReg must be set to a 0 to enable RTC
MinReg CON $01 ' minutes address (00 - 59)
HrReg CON $02 ' hours address (01 - 12) or (00 - 23)
DayReg CON $03 ' day address (1 - 7)
DateReg CON $04 ' date address (01 - 28/29, 30, 31)
MonReg CON $05 ' month address (01 - 12)
YearReg CON $06 ' year address (00 - 99)
' Alarm 1 Address definitions
' ====================
Alm1sec CON $07 ' Alarm 1 seconds address (00 - 59)
Alm1min CON $08 ' Alarm 1 minutes address (00 - 59)
Alm1hr CON $09 ' Alarm 1 hours address (01 - 12) or (00 - 23)
Alm1Day CON $0A ' Alarm 1 day address (1 - 7)
' Alarm 2 Address definitions
' ====================
Alm2min CON $0B ' Alarm 2 minutes address (00 - 59)
Alm2hr CON $0C ' Alarm 2 hours address (01 - 12) or (00 - 23)
Alm2Day CON $0D ' Alarm 2 day address (1 - 7)
' Alias of Clock register addresses
' ========================
ContReg CON $0E ' CONTROL register address
StatusReg CON $0F ' STATUS register address
' Clock Variables
' ===========
sec VAR BYTE ' seconds
MINs VAR BYTE ' minutes
hr VAR BYTE ' hours
day VAR BYTE ' day
date VAR BYTE ' date
mon VAR BYTE ' month
yr VAR BYTE ' year
' ALARM1 VARIABLES
' ==============
A1sec VAR BYTE ' seconds
A1MINs VAR BYTE ' minutes
A1hr VAR BYTE ' hours
A1day VAR BYTE ' day
' ALARM2 VARIABLES
' ==============
A2MINs VAR BYTE ' minutes
A2hr VAR BYTE ' hours
A2day VAR BYTE ' day
GoSub SetTimeAndDate ' Setup current time & alarm settings
'SETUP FOR INTERRUPTS
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
;INT_Handler USB_Handler
INT_Handler INT2_INT, _Alarm, PBP, yes
endm
INT_CREATE ; Creates the interrupt processor
ENDASM
@ INT_ENABLE INT2_INT ; enable external (INT) interrupts
INTCON.7 = 1 ' Set Global Interrupt Enable bit
INTCON2 = %00000000 ' Set INT2 for falling edge (Bit4-low)
' on RTC's interrupt.
INTCON3 = %10010000 ' Set INT2 high priority (Bit7-high), enable INT2
' (Bit4-high)
RTC_INT_FLG VAR INTCON3.1 'Alias for RB2 INTA interrupt flag from RTC
'[ Begin Main Program Loop ]
Main:
GoTo Main ' Endless Loop waiting for interrupt
End ' Safety measure to insure program stops if reaches here
'[ Begin Interrupt Handler
Alarm:
'Put your interrupt service routine code here
' Process the RTC alarm
' Read the current time and ALARM settings from the DS1337
I2CRead SDA, SCL, RTCdevice, SecReg,[sec,MINs,hr,day,date,mon,yr]
Pause 1000
' Clear the Alarm flags to be ready for next intterupt
' Clear STATUS register
I2CWrite SDA, SCL, RTCdevice, StatusReg,[$00]
Pause 1000
WRITE 255, sec
PAUSE 20
RTC_INT_FLG = 0 ' Clear PIC interrupt flag for next Alarm
PAUSE 1000
' Resume Main Program
@ INT_RETURN
End ' Safety measure to insure program stops if reaches here
'{ End of Interrupt Handler }
' [ START LIST OF SUBROUTINES
SetTimeAndDate: ' Subroutine to set current time, date and alarms
'==============
' Initialize clock variables to 0
yr=0:date =0:mon =0:day=0:hr=0:MINs=0:sec=0
A1sec=0:A1MINs=0:A1hr=0:A1Day=0
A2MINs=0:A2hr=0:A2day=0
' The BCD constants below set the RTC to: 11:00:00 on 12-20-2009
hr=$11
MINs=$00
sec=$00
day=$07
mon=$12
date=$20
yr=$09
' Per MAXIM TechSupport, proper sequencing requires setting INTCN = 1,
' & A2IE=A1IE=0 before setting alarms.
I2CWrite SDA, SCL, RTCdevice, ContReg,[%00000100]
Pause 20
'Define ALARM1 FOR 11:01:00 & to alarm when secs match (1/min).
' This requires A1M1=0 and A1M2=A1M3=A1M4=1
' (A1xxx + $80 or A1xxx + 128d sets bit 7 as A1Mx = 1)
A1hr = %10010001 '$11 + $80 = %10010001, for A1M3 = 1
'Bit6 must be 0 for 24 hour clock
A1MINs = %10000001 '$501 + $80 = %10000001, for A1M2 = 1
A1sec = $00 '$00 = %00000000, for A1M1 = 0
A1day = %10000111 '$07 + $80 = $10000111, for A1M4 = 1
'DY/_DT Bit6 = 0 for using Day of month alarm
' Per MAXIM TechSupport, reset control register for desired Alarm
' after setting alarms.
I2CWrite SDA, SCL, RTCdevice, ContReg,[%00000101]
PAUSE 20
'Set the main Time
I2CWrite SDA, SCL, RTCdevice, SecReg,[sec,MINs,hr,day,date,mon,yr]
Pause 20
'Set the Alarm1 Time
I2CWrite SDA, SCL, RTCdevice, Alm1sec,[A1sec,A1MINs,A1hr,A1day]
PAUSE 20
' Clear STATUS and set CONTROL registers
I2CWrite SDA, SCL, RTCdevice, StatusReg,[$00] ' Clear STATUS register
PAUSE 20
I2CWrite SDA, SCL, RTCdevice, ContReg,[%00000101]
' Starts the oscillator,
' enables INTA interrupt from A1F.
' WORKS as intended!!
Pause 20
Return
' If the user program ends by getting to the last statement of the
' program at an END instruction, the MCU will SLEEP and await a wakeup.
END
Some sample interrupt code for DS1337
Originally Posted by peu
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