Digital touch Screen Combination lock

[richard]

As this statement, how could we read the status of the actual pin without using the port as input. Could you please explain to me the method?

simply put you cannot , reading portx is the only direct way to read the actual status of the pins.

what henrik means is why would you read a port to read the value of outputs you have already set. the outputs will be at the level you set them to
(after a suitable interval to allow pin to settle) {providing load is acceptable}.

what are trying to do ?

[richard]

do you mean something like this

no need to wear out the eeprom

ANSELA = 0
    DEFINE OSC 64 
    OSCCON = $70
    OSCTUNE.6 = 1
    TRISA = %11111100 
                             
led1 var porta.0    ; alias led1 to porta.0
led2 var porta.1    ; alias led2 to porta.1
x    var bit            ; tried to use X var as a bit in order to hold the value of the actual status of the pin.


 


x = 0                  ; we write 0 to var X




loopy:
lata.0 = 1           ; we write 1 to lata.0
gosub holdmem  ; gosub to holdmem


pause 500
led2  = x      ; write the value of x to led2
pause 500
led1=0
@ nop
led2=0
pause 1000
goto loopy


holdmem:
x = led1  ; read the state of the porta.0 and place it in x
'x = lata.0  ;or  read the state of the lata.0 and place it in x
return
 
goto loopy

[astanapane]

do you mean something like this

no need to wear out the eeprom

ANSELA = 0
    DEFINE OSC 64 
    OSCCON = $70
    OSCTUNE.6 = 1
    TRISA = %11111100 
                             
led1 var porta.0    ; alias led1 to porta.0
led2 var porta.1    ; alias led2 to porta.1
x    var bit            ; tried to use X var as a bit in order to hold the value of the actual status of the pin.


 


x = 0                  ; we write 0 to var X




loopy:
lata.0 = 1           ; we write 1 to lata.0
gosub holdmem  ; gosub to holdmem


pause 500
led2  = x      ; write the value of x to led2
pause 500
led1=0
@ nop
led2=0
pause 1000
goto loopy


holdmem:
x = led1  ; read the state of the porta.0 and place it in x
'x = lata.0  ;or  read the state of the lata.0 and place it in x
return
 
goto loopy

yes i think this is what i wanted to do. But when we use the following command:

x = led1  ; read the state of the porta.0 and place it in x

arent we write to EEPROM? Or this is temprorarly held in memory?

[richard]

arent we write to EEPROM? Or this is temprorarly held in memory?

your lack of understanding exceeds my wildest expectation ,i wasn't prepared for a beginner.
if you like pm with me with your email and i will send a pic tutorial book i have as a pdf . its too big to post on forum


until you comprehend the basic concepts of memory types and uses , binary numbers , basic boolean algebra , logic
operators , i/o concepts ..... its just too hard

[astanapane]

thanks Richard will do.

[astanapane]

simply put you cannot , reading portx is the only direct way to read the actual status of the pins.

what henrik means is why would you read a port to read the value of outputs you have already set. the outputs will be at the level you set them to
(after a suitable interval to allow pin to settle) {providing load is acceptable}.

what are trying to do ?

The program for the lockcode, at the moment works fine. As mentioned in my first post im not a programmer, i had to find a way to make it work.

So the best suitable solution for me is to light up some LEDs and then read the status of the ports for confirmation.

That's why i made those pins as output and then read the status to confirm if they are 0 or 1.