The y with the two dots above it is what you get when you try to print a -1 as a character. The -1 is also what you get when you try to read serial data that isn't there.
The NewSoftSerial class has a method, available(), that tells you how many bytes of data are available to read. Use that method, and don't try to read serial data when none is available.
Or, don't store (or print) the value when it isn't valid.
Why are you calling pinMode for the tx and rx pins? NewSoftSerial takes care of that.
Aside from that, if you are not getting data from the GPS, it is either not connected to the pins you are reading from, is not getting power, is not grounded properly, or is not communicating at the baud rate that you specified.
the buad rate for gps is 4800 from the data sheet, and the buad rate of PC IS 9600, the red led of gps is on (so power is ok). also the ground is ok?!!!
i want to navigate from waypoint to anathor waypoint, if anyboady can help me with code?
The code to do what? To collect the GPS data on the Arduino? To parse the data to determine the location? To input another location? To compute the distance and direction to the new location? To actually move something in that direction?
what i want exactly is the follwoing:
move from point to other point, so i need to calculate the distance between them and the heading angle also, and how i can feed these data to dc motors of the robot?