Here is a link to the FAQ of a BU-353-S4 the GPS that I use:
I am a user of gpsd and not a dev., but I am realize that my questions need to be looked at by the devs' in order to add to their wish list and bug list in the way that they would state it. I also
figure the FAQ, might be helpful to add options. If I am not clear, please reply with a question/statement on the matter.
I have not learn how to use gpsd well, but I would like to know how to make sure WAAS is working both in Sirf binary and NMEA inside gpsd.
The receiver datasheet states the NMEA 0183 Output messages are GGA, GSA, GSV,
and RMC; along with the optional VTG and GLL.
How can I use these option messages with gpsd?
The datasheet also states that 48 channel all-in-view tracking, yet only a dozen sat are seen with gpsmod. I am not sure if there is a need for more fixes in that I am not sure that these are all used. If they can be used, how to allow them to be used?
Using gpsmon with Sirf binary under "Measured Tracker" are the items "Stat C/N ? SF" what are these four items?
Why do I get a "Read error from device" after some time with Sirf binary but not NMEA?
I do not know how but, it also seems to work in 9600 bps mode. Is this a good thing, will thing be damaged?
I get the following error message while no gps type device is running :
$
gpsctl /dev/ttyUSB0 -n
gpsctl:ERROR: error 'Multiple subscribers, cannot change control bits on /dev/ttyUSB0.'
gpsctl:ERROR: /dev/ttyUSB0 mode change to
NMEA failed
What do I need to do to get the GPS in NMEA mode and using WAAS?
I plan on buying a total of four receivers and try to do something like this article (which I can not read because it is behind a paywall)
How I understand it, the information from 4 gps are merged into one data point similar to gpsprof (however as a running total average), but broadcast out like single NMEA gpsd stream. I expect them to use
/dev/ttyUSB0 to ttyUSB4 for devices, but I don't see how they are all
read/write with only one port. If I use four USB receivers, and a hub, how can I do this? Even better what software can I use to do this?
John W. Nicholson