Can you elaborate your question a little? nmea_navsat_driver is a package, how can you subscribe to that. Do you mean you have the /fix topic available but somehow want to subscribe and read latitude and longitudes from that in a code? (what code? Python/C++, have you written a subscriber already?)

Sorry, for not clarifying my question. I am using Python, I have the /fix topic. I don’t have access to my code now but my subscriber looks like this: rospy.Subscriber("/fix", Sentence, callback)

I included from nmea_msgs.msg import Sentence at the beginning of the code.

Like you said, my goal is to find a way to read just the latitude and longitude. If you need my full code, I will able to provide it later today when I get my computer. Thank you for your answer.

Please edit your post and show us an actual message from your "fix" topic. Format it with the 101010 button.

You setup seems unusual; "fix" is usually a sensor_msgs/NatSatFix message, not a nmea_msgs/Sentence message.

Mike, thank you very much. I was able to do what I wanted, the problem as you mentioned was that I used the wrong message type. Here is how I did it:

from sensor_msgs.msg import NavSatFix

def __init__(self):
self.sub_gps = rospy.Subscriber("/fix", NavSatFix, self.gps_callback, queue_size=1)

def gps_callback(self, data):
    rospy.loginfo('Latitude: %s', data.latitude)
    rospy.loginfo('Longitude: %s', data.longitude)
    self.latitude_robot = data.latitude
    self.longitude_robot = data.longitude
    return

This is just the essential of the code

I suggest you make this comment the answer. Then click the checkmark in the gray circle to the left of the answer.