High End Pre with PIC 16F876A

[abidr]

Hi Guys:
I am quite new to PIC Programming and I thought it would be an excellent place to learn about it at this forum.
I have been working on this idea of developing a high end pre around PIC 16F876A, though as far as I could go the porject works fine as long as I use up, down and mute buttons.
But I cannot figure out a way how to configure that input selection stage so that one button changes the input (a total of four inputs) and when it reaches input 4, any new press on button input shifts the input to "input 1". I use ULN2803 for driving relays.
Appreciate if guys here could help me out.
Abidr

[mackrackit]

Not sure what you are after

so that one button changes the input

but this may give you an idea. http://www.picbasic.co.uk/forum/showthread.php?t=8602

Or maybe use "count" routine. every time the button is pressed the counter increases. If the count VAR is 1 do something. If count VAR is 2 do something else. If count VAR > 4 then count VAR = 0.
Is that what you need?

[abidr]

thanks "mackrackit"
link is not helpful.
Other part is that is VAR=0 then input is "IPOD" if input =2 etc.
My issue is how to define variable "an exmaple will be of great help" and how to shift the command to ULN2803 again an example will help.
Attached is picture of populated PCB of the project
abidr

[mackrackit]

The count code would be something like this

Bcnt VAR BYTE ' variable for counting
Button VAR PORT?.? 'PIN FOR BUTTON

MAIN:
IF Button = 1 then Bcnt = Bcnt + 1
IF Bcnt > 4 then Bcnt =0
IF Bcnt = 1 then GOSUB someplace1 ' after done at the gosub "return"
IF Bcnt = 2 then GOSUB someplace2
so on and so on

That is the basics, you may need a debounce routine and pauses. Maybe some endifs and elses too.

The sub routines would have something like
HIGH PORT?.?
This pin will be connected to the pin on the 2803 that you want to trigger.

[abidr]

Thanks dave heres is the code:
ACTIVATE_RELAY:

LOW MUTE ' Activate MUTE

select case RELAY

case 1 : PORTD = %10000000
PAUSE 500
case 2 : PORTD = %01000000
PAUSE 500
case 3 : PORTD = %00100000
PAUSE 500
case 4 : PORTD = %00010000
PAUSE 500
end select

GOSUB SHOW_INPUT
HIGH MUTE
IF RELAY_FLAG = 0 THEN GOTO MAIN

RETURN

SHOW_INPUT:

select case RELAY

case 1 : LCDOUT $FE, $C0,"DVD 5.1 "
case 2 : LCDOUT $FE, $C0,"USB DAC1"
case 3 : LCDOUT $FE, $C0,"USB DAC2"
case 4 : LCDOUT $FE, $C0,"CD "
end select
RETURN
Let me give it a try I guess it should work now.

[mister_e]

If you need to count how many time a button have been pressed, you may use RA4/T0CKI. really easy to setup and work really fine. The only thing you need to read/reset is TMR0 register.