Hi, /dev 
It works. I only have to understand how variables work.
Now I read:
N/F 0 sats (NoFix)
t 0 sats (only time)
N/F 1 sat (1 sat, but appears again NoFix)
...
F 5 sats
else if (fix.status == gps_fix::STATUS_NONE) lcd.write(byte(0));
makes appear NF symbol when are received 1 or more sats before fix...