Controlling Relays

[tazntex]

The value of Keydata is 0 if no key is pressed: here is how I've set that,
if keyin = nokey then keydata = %00000000

Thank you for your help.

[tazntex]

define osc 4
INCLUDE "MODEDEFS.BAS"
CMCON = 7
serpin var porta.3
nokey con %11111111
preamble con %01010101
synch con 254
keyin var portb
keydata var byte
trisb = %11111111
trisa = %00010111
key1 VAR PORTB.0
key2 VAR PORTB.1
key3 VAR PORTB.2
key4 VAR PORTB.3
key5 VAR PORTB.4
key6 VAR PORTB.5
key7 VAR PORTB.6
na VAR PORTB.7




findkey:
clear
pause 50
if key1 = 0 then sw1
if key2 = 0 then sw2
if key3 = 0 then sw3
if key4 = 0 then sw4
if key5 = 0 then sw5
if key6 = 0 then sw6
if key7 = 0 then sw7
if key8 = 0 then sw8

goto findkey

sw1:
keydata = 1
goto transmit
sw2:
keydata = 2
goto transmit
sw3:
keydata = 3
goto transmit
sw4:
keydata = 4
goto transmit
sw5:
keydata = 5
goto dout
sw6:
keydata = 6
goto transmit
sw7:
keydata = 7
goto transmit
sw8:
keydata = 8
goto transmit




transmit:

serout serpin,N2400,[preamble,synch,keydata]
pause 50
if keyin = nokey then keydata = %00000000
goto findkey


end

[skimask]

All define's must be capitalized (not that it makes any difference in this case)

[sayzer]

1. There is no Key8.
2. You can send the content of the whole PORTB when a change occurs; may be it would be more convenient but it is up to your choice.

For example:

FindKey:
     CLEAR
     KeyData = PORTB                    
     PAUSE 50
     IF PORTB = KeyData THEN FindKey   'Transmit only if there is at least a (one) change on PORTB. 

     SEROUT SerPin,N2400,[PreAmble,Synch,PORTB]
     PAUSE 50
         
     GOTO FindKey

This code will transmit the content of the PORTB every time there is a change on PORTB.
Thus, for instance, if PORTB.0 is 0, it will transmit, and then if it is still 0, it will NOT transmit.
If PORTB.0 is still 0 and then another change occurs at say PORTB.1 then it will transmit.

This way, you can handle the process at receiver side.