'


sertxd("online",13,10)
i2cslave %10100000, i2cfast, i2cword
high 5
w1=0
if input0=0 then readback



main:
'if b7 = 'V' then no signal, if 'A' then signal

serin 2, N4800,("$GPRMC,"),b0,b0,b0,b4,b5,b6,b0,b7
if b7 = "V" then goto nosig

'altitude
'serin 2,N4800,("$GPGGA,"),b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b9,b0,b0,b0,b0,b0,b0,b0,b0,b1,b2,b3,b4,b5,b6,b7,b8

'serin 2, N4800, ("$GPGGA,"), b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b1,b2,b0,b4
'Sertxd(13,10,"Ele=",b1,b2,".",b4) 'show it on LCD
'pause 100

'48 characters to skip first
serin 2,N4800,("$GPGGA,"),b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b0,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13

'sertxd(13,10,"KPH=",b1,b2,".",b3) 'show it on LCD

if b7="," then case1
if b8="," then case2
if b9="," then case3
if b10="," then case4
if b11="," then case5
if b12="," then case6
	
sendalt:
if b5="," then lockbuterror
low 5
pause 100
high 5
sertxd(13,10,"Alt=",b5,b6,b7,b8,b9,b10,b11,b12,13,10,"w1:",#w1) 'show it on LCD
writei2c w1,(b5,b6,b7,b8,b9,b10,b11,b12)
pause 200
'readi2c address,(b5,b6,b7,b8,b9,b10,b11,b12)
'sertxd(13,10,"Alt2=",b5,b6,b7,b8,b9,b10,b11,b12) 'show it on LCD

w1=w1+8

goto main

nosig:
sertxd("No signal!",13,10)
low 5
pause 50
high 5
pause 50
low 5
pause 50
high 5

goto main


case1:

b7=0
case2:
b8=0
case3:
b9=0
case4:
b10=0
case5:
b11=0
case6:
b12=0

goto sendalt



readback:

	
	readi2c w1,(b5,b6,b7,b8,b9,b10,b11,b12)
	if b5=0 then done
	sertxd(b5,b6,b7,b8,b9,b10,b11,b12)
	w1=w1+8
	low 5
	pause 200
	high 5 
	pause 50
	low 5
	pause 50
	high 5
	goto readback	
done:
	low 5
	end		

lockbuterror:
low 5
goto main