hi all,
i am dealing with a rf transmitter and receiver project. there are 3 transmitter and 1 receiver used in this project. transmitter used pic16f84a and the receiver used 16f877a.
below is the code


transmitter:
include "modedefs.bas"
define osc 4
input porta.0
output portb.0
output portb.1
output portb.2
output portb.3

led_on:
high portB.1
if porta.0=1 then transmit

transmit:
low portb.1
high PORTB.2
serout PORTB.0,N9600,["A",1]--(tansmitter1),
--serout PORTB.0,N9600,["A",2]--(transmitter2)
--serout PORTB.0,N9600,["A",3]--(transmitter3)


low PORTB.2
low portb.1
goto led_on


end




receiver:


serin PORTB.2,N9600,["A"],rx


SELECT CASE rx
CASE 1
goto station1

CASE 2
goto station2

CASE 3
goto station3

END SELECT


station1:

lcdout $FE,1, "station one"

portb.6=0
portb.3=1

pause 2000
portb.3=0
goto loop


station2:

lcdout $FE,1, "station two "
portb.6=0
portb.5=1
pause 2000
portb.5=0

station3:
lcdout $FE,1, "station three "
portb.3=1
portb.5=1
pause 1000
portb.3=0
portb.5=0
goto loop
end



my problem now is at the receiver i use lcd to test the result and i found out the serin command at the receiver and the select case below it also did not perform at all.It just direct go through content in station 1 only. station 2 and 3 totally did not perform.


another problem is i want to define the value of X1, X2,X3, Y1,Y2,and Y3.
but the value of X1,Y1,and X2 are negative value so how can i deal with it?all in word.
X1 = ? (X1=-2)
Y1 = ? (Y1=-2)
X2 = ? '(X2=-2)
Y2 = 6000 '(Y2=6)
X3 = 6000 '(X3=6)
Y3 = 6000 '(Y3=6)


hope to hear u soon.thank you for ur consideration.