PIC keeps resetting when executing subroutine

**jbirnsch** · - 26th August 2009, 01:25

All,

I am having problems with the below code when the subroutine warning is executed. PortA.0 is pulled high with a 1k. When the bin is full the limit switch pulls PortA.0 low. The buzzer and light will blink 2 times then the PIC will reset. I have used 2 different PIC's. - F84A and F819. Both PIC's do the same thing. 5V is solid and I have plenty of decoupling and bulk capacitance sprinkled throught the circuit. For the warning lamp and buzzer driver I use 1k to the base of a 2N4401 transistor's to drive the light and buzzer. I tried Tris statements and ADCON setup with the F819 with no help. I have tried HC and XT osc drive settings. Both parts are rated for 20MHz operation. I set power up timer to off and brownout off. All I want is the buzzer and light wo toggle 5 times then if the switch is still low at PORTA.0 then just have the binlight on until PORTA.0 hoes high. I'm about to smash this with a hammer soon as something this simple should not cause this much trouble.

Any help here is appreciated.

Code:

'****************************************************************
'*  Name    : Combine.BAS                                      *
'*  Author  : [select VIEW...EDITOR OPTIONS]                    *
'*  Notice  : Copyright (c) 2009 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 8/15/09                                           *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************

define OSC 20

'ADCON0 = %11000001
'ADCON1 = %10001110

'trisa = %00001110
'trisb = %11110111

binlight    var     porta.1
buzzer      var     portb.2
backup      var     porta.2
alarm       var     byte

define LCD_DREG PORTB
DEFINE LCD_DBIT 4  
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 1
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 0
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50
 
low buzzer
low binlight
low backup

PAUSE 500
alarm = 0
high buzzer
high binlight
high backup
pause 500
toggle buzzer
toggle binlight
toggle backup

LCDOUT $FE,1
LCDOUT $FE,$80, "TattleTale X"
LCDOUT $FE,$C0, "   Monitor"
pause 5000
LCDOUT $FE,1

monitor:

LCDOUT $FE,$80, "  No Alarms"
LCDOUT $FE,$C0, " "
if alarm = 1 then
goto light
endif
if PORTA.0 = 0 thEN
alarm = 1
GOsub warning
ELSE 
GOto monitor
endif


warning:
LCDOUT $FE,1
LCDOUT $FE,$80, " BIN FULL!!!"
LCDOUT $FE,$C0, " "
high binlight
high buzzer
pause 200
toggle binlight
toggle buzzer
pause 200
toggle binlight
toggle buzzer
pause 200
toggle binlight
toggle buzzer
'pause 200
'high binlight
'high buzzer
'pause 200
'low buzzer
'low binlight
RETURN


light:

if PORTA.0 = 0 then
high binlight
else
alarm = 0 
GOTO monitor
endif

**Jerson** · - 26th August 2009, 01:55

monitor:
LCDOUT $FE,$80, " No Alarms"
LCDOUT $FE,$C0, " "
if alarm = 1 then
goto light
endif

if PORTA.0 = 0 thEN
alarm = 1
GOsub warning
endif
GOto monitor

This might be better.

**jbirnsch** · - 26th August 2009, 04:07

It still resets when the warning subroutine is run. I am going to try another computer to compile and generate the hex code. I am currently useing an ancient laptop with 98SE.

**mackrackit** · - 26th August 2009, 04:39

Just for fun, replace the tranistor driveres, buzzers, lamps with LEDs.
Could still be a hardware problem and this will tell.

**jbirnsch** · - 26th August 2009, 05:18

I can remove the buzzer and lamps by unplugging a connector and the PIC still resets as I can see what's going on with the LCD screen. I tried a different computer and the result is the same.....

**jbirnsch** · - 26th August 2009, 05:34

Maybe you are browning out due to inadequate power supply

I checked that also with my scope. Power is solid.

I am using a 2A DC/DC converter PT6212E-5 on my circuit board with plenty of bulk capacitance. I have used these parts on many of my other PIC projects without problems. I am using a 3S1P Lipoly battery pack that can supply 30A cont current for my 12V input until it can be installed. I am using PBP V2.46 with the patch installed and the latest beta programming software with my epic programmer. The epic software on CD V3.30 gives the same reset problem...

Jason