Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
My code posted below works well, but I have learned that the ISR stops logging the date/time stamp for each DT_INT-18 INT2 interrupt received as an Alarm1 from a DS1337 clock after about 30-40 interrupts. Can anyone tell me why? I don't think it is related to the DS1337 generating the Alarm1 signals, because it works fine during the 30-40 working interrupts and the clock is still working and displaying correctly after the ISR stops afteer 30-40 interrupts.
Code:
'STATUS: Compiles & assembles OK with CPU @ 48 MHz or 16 MHz.
' Sets date/time/Alarm1 OK.
' Displays initialized date/time continuously.
' Logs date/time stamps for interrupts into EEPROM.
' For some unknown reason intterupts stop after 30-40 interrupts.
'***********************************************************************
'* Name : SetDS1337clock.pbp *
'* Author : John R. Ellis *
'* Notice : Copyright (c) 2010 LodeStar Associates, Inc. *
'* : All Rights Reserved *
'* Started : 07/19/2011 *
'* Version : 1.0 *
'* Notes : 1) This code was designed/devloped on an EasyPic6 *
'* Compiler: PICBASIC PRO Compiler 2.60C from microEngineering Labs *
'* Device : 18F2550 or 4550 w/ serial 2x16 or 2x8 LCD as installed on*
'* ProtoBoard connected via Port Extension to an EasyPic6. *
'* Memory : 3,268 bytes of Program Memory required. *
'* Ref: : 1) RTC portions of this code are adapted from code *
'* : written by Tonigalea (see URL ref below), but modified *
'* : to run on an EasyPic6 with 18F4550 MCU and a DS1337 RTC. *
'*http://www.picbasic.co.uk/forum/showthread.php?t=662&highlight=DS1337*
'* *
'***********************************************************************
' -----------------------[ Program Description ]--------------------------
' PICBASIC PRO program to set RTC & demo operation of a LCD/4-bit mode *
' 1) Initializes 2x16 or 2x8 LCD display with EasyPic6. *
' 2) Initializes DS1337 Real-time-clock & sets time/date/Alarm1. *
' (user must adjust code in SetTimeDate subroutine for desired *
' startup time/date/Alarm1 settings) *
' 3) This code sets Alarm1 to go off every minute..adjust as needed. *
' 4) Also displays date/time on LCD every second. *
' 5) If battery is so low to drop Vr<=3.39 vdc, LED_RED will blink *
' 5 times as a low voltage warning monitor. *
' *
'*************************************************************************
' -----------------------[ Revision History ]-----------------------------
' Version 1.0 Started on 07/19/11
' ------------[ NOTES for use with EasyPic6 development board ]-----------
' Make sure that SW6.8 on the EasyPic6 is set to ON position before
' powerup for LCD's requiring backlight.
'For use with 2x16 LCD:
' - Turn on Port Expander switches SW6.1, SW6.2, SW6.3, SW6.4 & SW6.5.
' - Turn on COG LCD 2x16 switches SW10.1, SW10.2, SW10.3, SW10.4,
' SW10.5 & SW10.6.
'For interface to DS1337 RTC:
' - To provide battery backup, place two Shottky diode in or configuration
' between the Vdd (pin-8) of the DS1337 and the Vcc source and the
' + terminal of the backup battery.
' - I2C communication lines should be connected to 4.7K pull-ups.
' - INTA & INTB lines should be connected to pull-up resistsors.
' - Turn off LEDs connected to I2C communication lines.
'-----------------18F2550/4550 Port/PIN Connections ]--------------------
'I/O pin connections to the 18F4550 MCU are as follows:
'PORTA.0 (02) connected to LCD D4.
'PORTA.1 (03) connected to LCD D5.
'PORTA.2 (04) connected to LCD D6.
'PORTA.3 (05) connected to LCD D7.
'PORTA.4 (06) connected to LCD RS.
'PORTA.5 (07) connected to LCD E.
'PORTB.0 (21) connected as I2C SDA output to DS1337.
'PORTB.1 (22) connected as I2C SCL output to DS1337.
'PORTB.2 (23) connected as INT2 interrupt from pin-3 (_INTA) of DS1337 RTC.
' Also senses pushbutton for manual interrupt.
'PORTB.3 (24) connected as input from SQW/_INTB pin-7 of DS1337 RTC.
'PORTB.4 (25) RB4 connected to Green LED to indicate USB connected & power on.
'PORTB.5 (26) RB5 not connected
'PORTB.6 (27) connected as PGC for ICSP connection.
'PORTB.7 (28) connected as PGD for ICSP connection.
'PORTC.0 (11) RC0 connected to control external power to Ultrasonic sensors.
'PORTC.1 (12) RC1 connected as an output to a Red LED for battery low.
'PORTC.2 (13) RC2 connected to LCD R/W.
'PORTC.3 (14) RC3/Vbus connected to 470 pf capacitor for USB
'PORTC.4 (15) normally connected as USB D-.
'PORTC.5 (16) normally connected as USB D+.
'PORTC.6 (17) normally connected as RS232 TX.
'PORTC.7 (18) normally connected as RS232 RX.
'--------------[ Define EEPROM usage ]-----------------------------------
'09 = day_cnt ' Most recent day_cnt
'10 = J ' Index for counting interrupts received
'11 = hr ' Hour time from RTC after setting RTC
'12 = MINs ' Minutes time from RTC after setting RTC
'13 = sec ' Seconds time from RTC after setting RTC
'14 = A1hr ' Alarm1 hour time from RTC after setting RTC
'15 = A1MINs ' Alarm1 minutes time from RTC after setting RTC
'16+J = mon ' Log Month
'17+J = date ' Log Day of Month
'18+J = yr ' Log Year
'19+J = hr ' Log Hour
'20+J = MINs ' Log Minutes
'21+J + sec ' Log Seconds
'240 = ID(0) ' LSB of device ID
'241 = ID(1) ' MSB of device ID
'242 = mon ' Month from clock
'243 = date ' Date in month from clock
'244 = yr ' Year from clock
'245 = hr ' Current hour of day from clock
'246 = MINs ' Current minute from clock
'247 = sec ' Current second from clock
'INCLUDE "CodeSize.pbp" 'FOR TEST ONLY
DEFINE Measure 1
;@ StartSize(LOOKUP) 'FOR TEST ONLY
Pause 10 ' This statement is placed at beginning of code for ICD use
Disable Debug
;-- 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
__CONFIG _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L
ENDASM
'--------------[ Define Hardware / Set Registers ]------------------------
DEFINE OSC 16
DEFINE I2C_SLOW 1 ' Set i2c to the standard speed
DEFINE I2C_HOLD 1 ' Enable recieving i2c device to pause communication
Include "Modedefs.Bas" ' Mode definitions for Debug,Serin/out,
' Shiftin/out, Xin/out.
INCLUDE "ALLDIGITAL.pbp" ' Sets all registers for digital ops.
' User must make sure AllDigital.pbp file
' is in same or higher directory location as
' this source code before compiling.
'DEFINE SHOWDIGITAL 1 ' When uncommented will show analog settings
' in Assembler Results window.
INCLUDE "DT_INTS-18.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas" ' Include if using PBP high priority interrupts
' Allows re-entry to PBP from a High Priority
' ASM interrupt. Must have DT_INTS-18.bas
' loaded first.
'OSCCON.7 = 0 ' Clear IDLEN bit to allow SLEEP mode
' According to data sheet, must clear CONFIG2H.0 (WDTEN bit)
' in order to use WDTCON. Not clear from Data sheet how to reach
' WDTEN bit with with config fuses??
'WDTCON.0 = 1 ' Set SWDTEN bit to turn on WDT
TRISA = 0 ' PortA output connections are used for LCD interface
TRISB = %00001100 ' RB2 & RB3 set as RTC Alarm1 & Alarm2 inputs
' PORTB.2 is also an input from switch grounding
TRISC.2 = 0 ' PortC.2 is used for the LCD R/W connection
CLEAR
;--- Setup Interrupts ----------------------------------------------------
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler INT2_INT, _Alarm, PBP, yes
endm
INT_CREATE ; Creates the interrupt processor
endasm
ENABLE DEBUG
' Per DT, DT_INTS already takes care of setting INTCON and RCON registers
' but this doesn't work unles INTCON2 set per below:
INTCON2 = %10000000 ' Set INT2 for falling edge (Bit4-low)
' on RTC's interrupt.
' Disable all PortB pull-ups (Bit7-high)
RTC_INT_FLG VAR INTCON3.1 'INT2 interrupt flag from RTC..DT_INTS handles
'--- Variables -----------------------------------------------------------
day_cnt VAR BYTE ' Counter for day number during monthly epoch
deviceID1 VAR BYTE ' Serial # of MCU (MSB)
deviceID2 VAR BYTE ' Serial # of MCU (LSB)
I VAR Byte ' Index for loop counters
ID VAR BYTE(8) ' Array for storing device ID parameters
J VAR BYTE ' Index to EEPROM address for logging
LCD_Flag VAR Bit ' Flag when set indicates LCD is installed/used
LED_RED VAr PortC.1 ' Red LED
LED_GRN VAR PortB.4 ' Green LED used to indicate Routine entries
SCL VAR PORTB.1 ' I2C clock pin
SDA VAR PORTB.0 ' I2C data pin
Spare_1 VAR PORTB.7 ' PGD for ICSP & Spare I/O for normal ops
Spare_2 VAR PORTB.6 ' PGC for ICSP & Spare I/O for normal op
X VAR Byte ' Used as an EEPROM memory index for logging
' Constants
'==========
RTCdevice CON $D0 ' Device write address = %11010000 for RTC
ENABLE DEBUG
'--- Initialize ----------------------------------------------------------
' Set FLAGS for current configuration
LCD_Flag = 1 ' Set for LCD installed/used; cleared otherwise
'CCPR1L = 0 ' Not used
'CCPR2L = 0 ' Not used
'CCP1CON = %00001100 ' CCP1, PWM mode...not used
'CCP2CON = %00001100 ' CCP2, PWM mode...not used
PR2 = 249 ' 0-1000 duty range
T2CON = %00000101 ' TMR2 on, prescaler 1:4
'OUTPUT PORTC.1 ' For slider bar only..not used in this app
'OUTPUT PORTC.2 ' For slider bar only..not used in this app
'--- Setup ADC
' A/D converters not used for this application
'DEFINE ADC_BITS 8 ; Number of bits in ADCIN result 'Not used
'ADCON2.7 = 0 ; left justify(Change this if ADFM in diff register)
'ADCON1 = %1101 ; AN0/AN1 Analog
;--- Read MCU Serial Number from device ID Locations
TBLPTRU=$20 ' Address $200000
TBLPTRH=$00
TBLPTRL=$00
For i = 0 To 7
@ TBLRD*+ ; Get value and increment the address
ID(i) = TABLAT ; Store the byte as ID(i)
Next
deviceID1 = ID(0) ' MSB of MCU Device Serial Number
deviceID2 = ID(1) ' LSB of MCU Device Serial Number
WRITE 240, ID(0) ' Write fixed values to EEPROM for test
WRITE 241, ID(1)
'--- Initialize epoch indexes at time of powerup/reset
day_cnt = 0
WRITE 9, day_cnt ' Store new epoch initialized day_count
'*******************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
' 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
' This is a list of allowable clock contrl settings, one which
' must be setup in the SetTimeAndDate subroutine for intended use.
'(see data sheet pgs 9-10 for explanation)
'contrl CON %00000000 ' Starts oscillar, sets the SQW/OUT to
' 1Hz pulse, no Alarm interrupts enabled.
' WORKS as intended!!
'contrl CON %00000001 ' Starts oscillator, sets the SQW/OUT to
' 1 HZ pulse, & enables INTA interrupt from
' A1F. WORKS as intended!!
'contrl CON %00000010 ' Starts oscillator, sets the SQW/OUT to
' 1 HZ pulse, enables INTA interrupt from
' A2F. WORKS AS intended!!
'contrl CON %00000011 ' Starts the oscillator, sets the SQW/OUT
' to 1 Hz, enables INTA interrupt from A1F
' or from A2F. WORKS as intended!!
'contrl CON %000xx100 ' Starts oscillator, no interrupts enabled.
' WORKS as intended!
'contrl CON %000xx101 ' Starts oscillator, enables INTA interrupt
' from A1F, INTB/SQW off. WORKS OK!
'contrl CON %000xx110 ' Starts oscillator, enables INTB interrupt
' from A2F. WORKS OK!
'contrl CON %000xx111 ' Starts oscillator, enables INTA interrupt
' from A1F or INTB from A2F. WORKS OK!
' Both interrupts staggered 30 secs apart.
'contrl CON %00011111 ' Starts oscillator, sets RS1 & RS2,
' enables INTA interrupt from A1F
' or A2F starts 32.768khz on SQW output.
' WORKS OK!
'contrl CON %00011001 ' Starts oscillator, sets RS1 & RS2,
' clears INTCN to enable INTA interrupt
' from A1F with 32.768kHz on SQW output.
' SQW output WORKS OK but INTA doesn't!
'contrl CON %00011010 ' Starts oscillator, sets RS1 & RS2,
' clears INTCN to enable INTA interrupt
' from A2F with 32.768kHz on SQW. WORKS OK!
' RTC Address definitions
SecReg CON $00 ' seconds address (00 - 59)
' Must set MSB of SecReg 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..not used in this application
'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 of week (Sunday = 7)
date VAR BYTE ' date in month
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..not used in this application
'A2MINs VAR BYTE ' minutes
'A2hr VAR BYTE ' hours
'A2day VAR BYTE ' day
GOTO JumpPoint ' Jump over all subroutines so they don't execute on powerup
' ----------------------[ START SUBROUTINES ]--------------------------
InitializeDisplay: ' Subroutine to initialize 2X16 or 2x8 LCD display
'=================
'-----SETUP FOR USING 2x16 or 2x8 LCD THAT IS INSTALLED IN EASYPIC6--------
' LCD DEFINES FOR USING 2x16 LCD with PortA in EASYPIC6
DEFINE LCD_DREG PORTA ' Use PORTA for LCD Data
DEFINE LCD_DBIT 0 ' Use lower(4) 4 bits of PORTA
' PORTA.0 thru PORTA.3 connect to
' LCD DB4 thru LCD DB-7 respectively
DEFINE LCD_RSREG PORTA ' PORTA for RegisterSelect (RS) bit
DEFINE LCD_RSBIT 4 ' PORTA.4 pin for LCD's RS line
DEFINE LCD_RWREG PORTC ' LCD read/write port
DEFINE LCD_RWBIT 2 ' LCD read/write bit
DEFINE LCD_EREG PORTA ' PORTA for Enable (E) bit
DEFINE LCD_EBIT 5 ' PORTA.5 pin for LCD's E line
DEFINE LCD_BITS 4 ' Using 4-bit bus
DEFINE LCD_LINES 2 ' Using 2 line Display
DEFINE LCD_COMMANDUS 1500' Command Delay (uS)
DEFINE LCD_DATAUS 44 ' Data Delay (uS)
' DEFINE LCD Control Constants
Line1 CON 128 ' Point to beginning of line 1 ($80)
Line2 CON 192 ' Point to beginning of line 2 ($C0)
' Test the LCD during initialization
LCDOut $fe,1:FLAGS=0:Pause 250 ' Clear Display
LCDOUT $fe,Line1,"POWER ON" ' Display on 1st line
LCDOUT $fe,Line2,"LCD TEST" ' Display on 2nd line
PAUSE 2000
Return
SetTimeAndDate: ' Subroutine to set current time, date and alarms
'==============
' Blink LED_GRN 2X times to indicate entered SetTimeAndDate
For i = 0 to 1
HIGH LED_GRN
Pause 500
LOW LED_GRN
PAUSE 500
Next
' Initialize the display & clock
Pause 100 ' Wait for LCD to startup after power on
' 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: 13:00:00 on 05-26-2010
hr=$13
MINs=$00
sec=$00
day=$03
mon=$05
date=$26
yr=$10
' Per MAXIM TechSupport, proper sequencing requires setting
' INTCN = 1, & A2IE=A1IE=0 before setting alarms.
I2CWRITE SDA, SCL, RTCdevice, ContReg,[%00000100]
PAUSE 10
'Define ALARM1 FOR 13:01:00 & 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 = %10010011 '$13 + $80 = %10010011, for A1M3 = 1
'Bit6 must be 0 for 24 hour clock
A1MINs = %10000001 '$01 + $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
'Define ALARM2 FOR 14:01:00 & to alarm once per minute (00 secs)
'Disabled in this application
' This requires A2M2 = A2M3 = A2M4 = 1
' (A2xxx + $80 or A2xxx + 128d sets bit 7 as A2Mx = 1)
'A2hr = $14 + $80 '$14 + $80 = %10010100, for A2M3 = 1
'Bit6 must be 0 for 24 hour clock
'A2MINs = $01 + $80 '$01 + $80 = %10000001, for A2M2 = 1
'A2day = $07 + $80 '$07 + $80 = $10000111, for A2M4 = 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 10
'Set the main Time
I2CWrite SDA, SCL, RTCdevice, SecReg,[sec,MINs,hr,day,date,mon,yr]
PAUSE 10
' Write date/time setting to EEPROM
WRITE 242, Mon
WRITE 243, Date
WRITE 244, Yr
WRITE 245, hr
WRITE 246, MINs
Write 247, sec
'Set the Alarm1 Time
I2CWrite SDA, SCL, RTCdevice, Alm1sec,[A1sec,A1MINs,A1hr,A1day]
PAUSE 10
'Set the Alarm2 Time ' Alarm2 disabled for this application
'I2CWrite SDA, SCL, RTCdevice, Alm2min,[A2MINs,A2hr,A2day]
'PAUSE 10
IF LCD_Flag = 1 Then ' This code block for testing only
'Test to see if Time set correctly by displaying on LCD
I2CREAD SDA, SCL, RTCdevice, SecReg,[sec,MINs,hr,day,date,mon,yr]
LCDOut $fe,1 ' Clear Display
LCDOUT $fe,Line1,"SetTime"
LCDOUT $FE,LINE2,hex2 hr,":",hex2 MINs,":",hex2 sec
PAUSE 3000 ' Delay so user can view display
'Test if Alarm1 set correctly by displaying stored Alarm1 time
I2CREAD SDA,SCL,RTCdevice,Alm1sec,[A1sec,A1MINs,A1hr,A1day]
LCDOut $fe,1 ' Clear Display
LCDOUT $fe,Line1,"SetAlm1"
LCDOut $FE,line2,hex2 A1hr,":",hex2 A1MINs,":",hex2 A1sec
PAUSE 3000 ' Delay so user can view display
ENDIF
' Clear STATUS and set CONTROL registers
I2CWrite SDA, SCL, RTCdevice, StatusReg,[$00]
PAUSE 10
I2CWrite SDA, SCL, RTCdevice, ContReg,[%00000101]
' Starts oscillator, no interrupts enabled.
' WORKS as intended!!
Pause 10
RETURN
' ----------------------[ END OF SUBROUTINES ]--------------------------
JumpPoint:
'Setup for starting Main Program
IF LCD_Flag = 1 Then GOSUB InitializeDisplay ' Initialize LCD before
' starting mainloop
GOSUB SetTimeAndDate ' Set RTC time/date before starting mainloop
IF LCD_Flag = 1 THEN ' This code block FOR TESTING ONLY
LCDOut $fe,1' Clear Display
LCDOUT $fe,Line1,"Entered"
LCDOUT $fe,Line2,"JumpPoint"
Pause 2000
ENDIF
'Initialize epoch indexes at time of powerup/reset
day_cnt = date
WRITE 9, day_cnt ' Store new epoch initialized day_count
Pause 20
J = 0 ' Initialize EEPROM logging index
'Initialize LEDs to off
LOW LED_GRN
LOW LED_RED
' Enable the interrupts that are to be active during main loop.
@ INT_ENABLE INT2_INT ; enable external (INT) interrupts
'--------------------[ Begin Main Program Loop ]-------------------------
;@ StartSize(MainLoop) ; FOR TEST ONLY
mainloop:
' Read current time/date
I2CREAD SDA, SCL, RTCdevice, SecReg,[sec,MINs,hr,day,date,mon,yr]
PAUSE 20
' Display current Date/Time
IF LCD_Flag = 1 THEN ' Display only if LCD installed
LCDOUT $fe,1 ' Clear Display
LCDOUT $fe,Line1,HEX2 mon,"/",HEX2 date,"/", HEX2 yr
LCDOUT $FE,Line2,HEX2 hr,":",HEX2 MINs,":",HEX2 sec
ENDIF
' Store current date/time in EEPROM
WRITE 242, Mon
WRITE 243, Date
WRITE 244, Yr
WRITE 245, hr
WRITE 246, MINs
WRITE 247, sec
GOTO mainloop
;@ EndSize(MainLoop) ; Uncomment FOR TEST ONLY
'--------------------[ Begin Interrupt Handlers ]------------------------
Alarm:
@ INT_DISABLE INT2_INT ; disable external (INT) interrupts
' Put code here for actions taken due to RTC Alarm1 interupt
LCDOUT $fe,1 ' Clear Display
LCDOUT $fe,Line1,"Entered"
LCDOUT $fe,Line2,"Alarm1!"
PAUSE 2000
WRITE 16+J, mon ' Log date/time stamp of most recent interrupt
WRITE 17+J, date
WRITE 18+J, yr
WRITE 19+J, hr
WRITE 20+J, MINs
WRITE 21+J, sec
J = J+6
IF date > day_cnt THEN
day_cnt = date ' Increment day_cnt as new epoch
WRITE 9, day_cnt
ENDIF
' Clear RTC STATUS and set CONTROL registers for next RTC interrupt
I2CWRITE SDA, SCL, RTCdevice, StatusReg,[$00]
PAUSE 10
I2CWRITE SDA, SCL, RTCdevice, ContReg,[%00000101]
@ INT_ENABLE INT2_INT ; enable external (INT) interrupts
@ INT_RETURN
'------------------{ End of Interrupt Handlers }-------------------------
End ' Safety measure to insure program stops if reaches here
;@ EndSize(LOOKUP) ; FOR TEST ONLY
;@ LibrarySize ; FOR TEST ONLY
;@ UserSize ; FOR TEST ONLY
;@ TotalSize ; FOR TEST ONLY
Re: Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
Here is what I would do in your code:
1. I would remove
@ INT_DISABLE INT2_INT and @ INT_ENABLE INT2_INT from your Alarm int routine.
2. You are continuously writing to EEPROM in your mainloop. Think about it as your face as if you were continuously shaving it without a single moment of stop. So it will die after a short time and your program will no longer be able to write on it.
3. When you need to write to EEPROM, I would suggest you do it either in int routine or after disabling the interrupt. For example, if you must write to EEPROM in mainloop, disable intterrupt and then write to eeprom and enable it. However, if you can do it in the int routine, you do not need to disable/enable interrupt.
Re: Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
Thanks, Sayzer, for this input. All three of your suggestions are logical and good. However, I implemented all three of your suggestions, and it still stops after exactly 23 interrupts on IN2.
Any other ideas from anyone as to why this is happening? Would really appreciate an input from Darrel Taylor.
John Ellis
Re: Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
What is the interrupt rate? 1 per second? Or 1 every minute?
I would recommend not to use heavy time consumers like LCDOUT and WRITE commands within the ISR as it can create problems.
Re: Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
I would try to get rid of the WRITE in the ISR first, but yeah, rule #1... keep ISR as short as possible, set some flags and process the dutys in the main loop.
Another thing.. get rid of all ENABLE/DISABLE DEBUG... for entertainment and testing purpose.
Re: Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
He has 2 seconds of pause in Int routine.
So I assume that the code is written with a logic that allows such a long pause in there.
Also, since there is an LCD, I would have a step number variable.
And, at each line of code, I would number the step variable and show on LCD.
This way, you will see where the program stops; so you can see the step number and check the code.
Re: Why does INT2 in DT_INT-18 stop working after 30-40 interrupts?
Thanks to all of you. All were good suggestions and I have implemented them all. Replacing the WRITEs in the ISR with a FLAG that is polled in the main loop to determine whether to WRITE the time stamp to EEPROM, fixed the problem.
Sayez's idea of using a step variable and LCD to troubelshoot where in code a problem exists is a great idea I had not heard before. Will definitely make use of it in future. Thanks!
This forum is one of the greatest resources that exists in the microcontroller design world. Thanks to all of you for your great participation and contributions!
John Ellis
