Problem with nmea_serial_driver

asked 2014-09-11 20:40:24 -0500

Hi, I'm trying to use the nmea_navsat_driver stack with a TOPCON GPS unit. However, the nmea_serial_driver starts and issues the following warnings:

   $ rosrun nmea_navsat_driver nmea_serial_driver _port:=/dev/ttyUSB4 _baud:=115200 
    [WARN] [WallTime: 1410482892.574839] Received a sentence with an invalid checksum.                 Sentence was: 
    [WARN] [WallTime: 1410482893.088193] Received a sentence with an invalid checksum.                 Sentence was: $GPGSA,M,3,16,32,20,11,22,01,,,,,,,2.71,1.81,2.01*04

but then goes quiet and doesn't publish any data across the fix and velocity topics. Via a serial monitor I can confirm that the NMEA sentences are being published correctly with the correct checksums. The above two messages seem to be just startup errors.

However I can get the system to work with nmea_topic_serial_reader combined with the nmea_topic_driver on the same settings. However in this configuration it doesn't issue velocity information (from the NMEA RMC message).

Any suggestions on how to get the nmea_serial_driver to work?

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Peter, are you still having this problem? If so, can you file an issue on so we can get it sorted out. There shouldn't be any difference between running with topics or without, so there's probably a bug somewhere in here that I need to fix.

Eric Perko gravatar image Eric Perko  ( 2015-01-23 10:39:52 -0500 )edit