Multiplexing indicators

What I'm trying to end up with is a clock displaying seconds, minutes, hours and maybe a few other things.

What I've been experimenting with so far is the seconds and minutes displays. The displays are 5082-7300 are hooked up to portc and there LEDs on portd.0 and portb.1. The LEDs are just so I know the program is running. I thought I had a schematic but I saved it in wrong format so I can update it later if needed.

Code:

''* Notes :This program will blink a light on portd.1 at * '* :about a 1 hz rate w/ LED on portb.1 set to 100cps * '* : * '**************************************************************** ' This program will count from 0 to 59 using porte.0 and porte.1 ' without writing a 60. ' Now trying to get the displays to sequence they look like they're ' always on. 'rearranging port outs to resemble final diagram output on portc ' portc outputs one and tens properly when latched from porte.1 '--------------------------------------------------clock variables ticks VAR BYTE seconds VAR BYTE minutes VAR BYTE hours VAR BYTE days VAR BYTE '-----------------------------------------------my variables secondschanged VAR BYTE 'seconds x VAR BYTE out_tens VAR BYTE minutes_changed VAR BYTE 'minutes minutes_count VAR BYTE tens_minutes VAR BYTE out_tens_minutes VAR BYTE '---------------------------------------------------testing variables led1 VAR portb.1 led2 VAR portd.0 ' blinks at pause rate trisc = %00000000 trise = %001 portc = 0 porte = 0 cmcon = %00000111 ' comparators off adcon0 = %00000000 ' adc off adcon1 = %11000110 ' sets AN ports to digital ccp1con = %00000000 ' turns comparator module off latch_enable VAR porte.0' pin 8 on 16f877a second_latch_enable VAR porte.1 'pin 9 on 16f877a tens_seconds VAR BYTE ' something for the tens digit to display '-------------------------------------------DT interrupt area wsave VAR BYTE $70 SYSTEM ' alternate save location for W ' if using $70, comment wsave1-3 INCLUDE "DT_INTS-14.bas" ' Base Interrupt System INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts DEFINE osc4 ASM INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler TMR1_INT, _ToggleLED1, PBP, yes endm INT_CREATE ; Creates the interrupt processor ENDASM T1CON = %00000001 ; Prescaler = 1:1, TMR1ON @ INT_ENABLE TMR1_INT ; enable Timer 1 interrupts preload VAR WORD preload = 60643 '60643 yeilds exactly 100 Hz w/ 1:1 prescaler tmr1l = preload.LowByte tmr1h = preload.HighByte seconds = 0 tens_seconds = 0 minutes_count = 0 tens_minutes = 0 Main: '--------------------------------------------increment seconds IF ticks > 50 THEN 'seconds counting to 59 ticks = 0 seconds = seconds + 1 IF seconds > 9 THEN tens_seconds = tens_seconds + 1 seconds = 0 ENDIF portc = (portc & %11110000) | seconds'tell the port which bits to use IF tens_seconds > 5 THEN tens_seconds = 0 minutes_changed = 1 ENDIF out_tens = tens_seconds * 16 trise = %110 ' porte.0 portc = (portc & %00001111) | out_tens 'tell the port which bits to use HIGH latch_enable ' enable write PAUSE 5 LOW latch_enable 'disable write PAUSE 5 ENDIF '-----------------------------------------------increment minutes IF minutes_changed = 1 THEN minutes_changed = 0 minutes_count = minutes_count + 1 IF minutes_count > 9 THEN minutes_count = 0 tens_minutes = tens_minutes + 1 ENDIF portc = (portc & %11110000) | minutes_count'tell the port which bits to use IF tens_minutes > 5 THEN tens_minutes = 0 out_tens_minutes = tens_minutes * 16 trise = %101 ' porte.1 portc = (portc & %00001111) | out_tens_minutes 'tell the port which bits to use HIGH second_latch_enable 'disable write PAUSE 5 LOW second_latch_enable PAUSE 5 ENDIF porte = 0 TOGGLE led2 GOTO Main '---[TMR1 - interrupt handler]------------------------------------ ToggleLED1: t1con.0 = 0 tmr1l = preload.LowByte tmr1h = preload.HighByte t1con.0 = 1 TOGGLE led1 ticks = ticks + 1 @ INT_RETURN END

First, I know it's running fast. I got impatient waiting for the digits to turn over so I sped it up. I'll fix that later.

The problem I'm having is with the ones digit in the minutes display. In my program I initially set all the indicators to zero but the minutes ones digit sets to a 1 immediately. As the program counts the ones and tens seconds display works well. When it comes time to chalk up another minute the ones digit shows the correct count only for a second, or as long as the seconds display is zero, then goes back to being a 1.

Can anybody tell me why or how to fix it so the digit retains the correct number?

Most of the time your thoughts are always welcome.

Re: Multiplexing indicators

First time through, minutes_changed is not initialized to a value (unless I missed it).

What if you set it to 0 at the top?

Robert

EDIT: You set it to a byte, maybe you get "unlucky" and hit a 0.

Re: Multiplexing indicators

It's always the simplest of things that get you. So in case anyone is interested, tt turns out setting TRISE, GPIOE and GPIOC at the end of the main loop solves the problem. I also set TRISE as an input early on but it wasn't necessary.

Code:

'**************************************************************** '* Name : UNTITLED.BAS * '--------------------------------------------------clock variables ticks var byte seconds var byte minutes var byte hours var byte days var byte '-----------------------------------------------my variables secondschanged var byte 'seconds out_tens var byte minutes_changed var byte 'minutes minutes_count var byte tens_minutes var byte out_tens_minutes var byte '---------------------------------------------------testing variables led1 var portb.1 led2 var portd.0 ' blinks at pause rate trisc = %00000000 trise = %111 portc = 0 porte = 0 cmcon = %00000111 ' comparators off adcon0 = %00000000 ' adc off adcon1 = %11000110 ' sets AN ports to digital ccp1con = %00000000 ' turns comparator module off latch_enable var porte.0' pin 8 on 16f877a second_latch_enable var porte.1 'pin 9 on 16f877a tens_seconds var byte ' something for the tens digit to display '-------------------------------------------DT interrupt area wsave VAR BYTE $70 SYSTEM ' alternate save location for W ' if using $70, comment wsave1-3 INCLUDE "DT_INTS-14.bas" ' Base Interrupt System INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts define osc4 ASM INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler TMR1_INT, _ToggleLED1, PBP, yes endm INT_CREATE ; Creates the interrupt processor ENDASM T1CON = %00000001 ; Prescaler = 1:1, TMR1ON @ INT_ENABLE TMR1_INT ; enable Timer 1 interrupts preload var word preload = 60643 '60643 yeilds exactly 100 Hz w/ 1:1 prescaler tmr1l = preload.lowbyte tmr1h = preload.highbyte 'seconds = 0 'tens_seconds = 0 'minutes_count = 0 tens_minutes = 0 Main: '--------------------------------------------increment seconds if ticks > 10 then 'seconds counting to 59 ticks = 0 seconds = seconds + 1 if seconds > 9 then tens_seconds = tens_seconds + 1 seconds = 0 endif portc = (portc & %11110000) | seconds'tell the port which bits to use if tens_seconds > 5 then tens_seconds = 0 minutes_changed = 1 endif out_tens = tens_seconds * 16 trise = %110 ' porte.0 portc = (portc & %00001111) | out_tens 'tell the port which bits to use high latch_enable ' enable write pause 5 low latch_enable 'disable write pause 5 endif '-----------------------------------------------increment minutes if minutes_changed = 1 then minutes_changed = 0 minutes_count = minutes_count + 1 if minutes_count > 9 then tens_minutes = tens_minutes + 1 minutes_count = 0 endif portc = (portc & %11110000) | minutes_count'tell the port which bits to use if tens_minutes > 5 then tens_minutes = 0 endif out_tens_minutes = tens_minutes * 16 trise = %101 ' porte.1 portc = (portc & %00001111) | out_tens_minutes 'tell the port which bits to use high second_latch_enable 'disable write pause 5 low second_latch_enable pause 5 endif porte = 0 trise = %111 portc = 0 toggle led2 pause 100 GOTO Main '---[TMR1 - interrupt handler]------------------------------------ ToggleLED1: t1con.0 = 0 tmr1l = preload.lowbyte tmr1h = preload.highbyte t1con.0 = 1 TOGGLE LED1 ticks = ticks + 1 @ INT_RETURN End