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drotek / SMARTNAV-RTK

Drotek SMARTNAV RTK - Hardware and Software - Open Source centimeter level positioning
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Automatic Base Coordinates : Wrong coordinates #14

Open kikislater opened 8 years ago

kikislater commented 8 years ago

Base + rover launched since 30minutes, sending "Automatic Base Coordinates" return wrong longitude. Good one is -1.1380...

screenshot_2016-09-06-15-53-04

klopezal commented 8 years ago

You are not the first one to notice this bug. First tests show it is a transmission problem. Messages are decoded and used without any precaution for the moment. We could take benefit of the checksum present in u-blox binary protocol to check every message integrity in order to discard uncorrect ones.

kikislater commented 8 years ago

Ok, could it be an issue with telemetry vs GNSS ? I use dragonlink dipole antenna. http://diydrones.com/forum/topics/433-mhz-dipole-vs-gps-total-decimation?commentId=705844%3AComment%3A2287857

I notice when using these antenna that I have less fix but telemetry module get a solid fixed led. I used standard 3dr telemetry module, I will try with 500mw and different power source

klopezal commented 8 years ago

It would be great if you could give it a try with a separate power source. But it could also be a simple error of transmission. In Europe 433 MHz frequency is quite jammed and as there is for the moment no checksum check, one error in one byte will give a false result because the arithmetic behind is a simple average of coordinates.