18F1220 LCD and Sleep

[jderson]

The program below is supposed to display "BEFORE SLEEP" on the LCD on power-up, then power-down the LCD and go to sleep. Upon external interrupt, the LCD is supposed to display "AWAKE AGAIN!", the LED comes on, and return to Main. With the "LOW PORTA.6" line commented out, the LCD displays both messages as it should. With the line in the program, the LCD goes blank as it should, but it only displays a single row of blocks during the "Awake" routine. The LED behaves as it should. What could be the problem?

TRISA = %00100000 ;RA5 input, all else outputs
TRISB = %10000111 ;RB0,1,2,&7 inputs
WDTCON = 0 ;WDT off
ADCON0 = %00000000 ;ADC off
ADCON1 = %01111111 ;All pins digital
LVDCON = %00000000 ;LVD off
CCP1CON = %00000000 ;CCP/PWM off
OSCCON = %01100000 ;RUN mode,4MHZ,INT OSC
RCON = %00000000 ;Prioritys off
EECON1 = %00000100 ;Access flash
INTCON2 = %11000000 ;Disable PORTB pullups,INT0 rising edge
INTCON3 = %00000000 ;INT1 enabled
PIE1 = %00000000 ;Disable A/D,EUSART,CCP,TMR2,TMR1 overflow ints
PIE2 = %00000000 ;Disable OSC Fail,EEPROM,LVD,TMR3 overflow ints
IPR1 = %00000000 ;A/D,EUSART,CCP,TMR2,TMR1 low priority
IPR2 = %00000000 ;OSC Fail,EEPROM,LVD,TMR3 ints low priority
RCON = %00000000 ;Disable priority levels
T0CON = %00000000 ;TMR0 off
T1CON = %00000000 ;TMR1 off
T2CON = %00000000 ;TMR2 off
T3CON = %00000000 ;TMR3 off
TXSTA = %00000000 ;Transmit disabled
RCSTA = %00000000 ;Receive disabled

@ __CONFIG _CONFIG1H, _IESO_OFF_1H & _FSCM_OFF_1H & _INTIO2_OSC_1H
@ __CONFIG _CONFIG2L, _PWRT_ON_2L & _BOR_OFF_2L & _BORV_27_2L
@ __CONFIG _CONFIG2H, _WDT_OFF_2H & _WDTPS_32K_2H
@ __CONFIG _CONFIG3H, _MCLRE_OFF_3H
@ __CONFIG _CONFIG4L, _DEBUG_OFF_4L & _LVP_OFF_4L & _STVR_OFF_4L
@ __CONFIG _CONFIG5L, _CP0_OFF_5L & _CP1_OFF_5L
@ __CONFIG _CONFIG5H, _CPB_OFF_5H & _CPD_OFF_5H
@ __CONFIG _CONFIG6L, _WRT0_OFF_6L & _WRT1_OFF_6L
@ __CONFIG _CONFIG6H, _WRTC_OFF_6H & _WRTB_OFF_6H & _WRTD_OFF_6H
@ __CONFIG _CONFIG7L, _EBTR0_OFF_7L & _EBTR1_OFF_7L
@ __CONFIG _CONFIG7H, _EBTRB_OFF_7H

DEFINE LCD_DREG PORTA
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTA
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50

INCLUDE "DT_INTS-18.bas" ; Base Interrupt System
INCLUDE "ReEnterPBP-18.bas" ; Include if using PBP interrupts

ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler INT_INT, _Awake, PBP, yes
endm
INT_CREATE ; Creates the interrupt processor
ENDASM

@ INT_ENABLE INT_INT ; enable external (INT) interrupts

Main:
HIGH PORTA.6 'LCD Power ON
PAUSE 1000
LCDOUT $fe,1,"BEFORE"
LCDOUT $fe,$C0,"SLEEP"
PAUSE 1000
'LOW PORTA.6 'LCD Power OFF
@ SLEEP
@ NOP

GOTO Main

'---[INT - interrupt handler]---------------------------------------------------
Awake:

HIGH PORTB.4 'LED ON
HIGH PORTA.6 'LCD Power ON
LCDOUT $fe,1,"AWAKE"
LCDOUT $fe,$C0,"AGAIN!"
PAUSE 100
LOW PORTB.4 'LED OFF

@ INT_RETURN

Thank you for any help.

[Jerson]

You've missed the pause 1000 after turning on the LCD power in your interrupt service. You need to give time to the LCD to initialize. Is that the cause?

[jderson]

Thanks for trying, Jerson. The pause just causes the blocks to be displayed longer.

[Acetronics2]

Hi, JDerson

See Manual $ 5.39 ...

"FLAGS" to clear before entering sleep ...

Alain

[jderson]

FLAGS = 0 solved the problem. Thank you for your help.