Hello everyone
I have recently purchased both a uBlox as well as a MediaTek GPS receiver. The MediaTek work works without any problems when connected to the ArduPilotMega, but I'm having problems with the uBlox. I also do not seem to be able to setup the MediaTek to operate at anything but 1Hz.
I am testign both of these receivers without the ArduPilotMega connected i.e. connected via USB to my laptop. I've also tried to get a GPS signal from the uBlox using ther MissionPlanner software, when the receiver is connected to the ArduPilotMega (this work for the MediaTek with no problem - except at 1Hz only)
So my problems are:
1. uBlox: usign U-Center I can 'see' the uBlox and update the firmware, but it does not manage to lock onto any satellites (I've left it running for around 45 minutes after choosing the cold start option). I've tried connecting using the header connecotrs on the MediaTek module as well as the regular GPS port connector. Any ideas on how I can solve this issue and get the uBlox working?
2. MediaTek: using MiniGPS I can update the firmware, update the refresh rate to 5Hz (no 10Hz option it seems) and switch on WAAS. None of these options seem to be stored on the receiver though after exiting MiniGPS. I've tried the "Write settings into flash" option but this fails. What can I do to retain the settings and hence get WAAS and the higher refresh rate (5Hz or 10Hz if I can find out how) to work when I'm connected to the ArduPilotMega?
Regards
Julian
Replies
Look in the NMEA manual for your unit. You may have to write support to get this. Some units also only allow 8 or so writes before you have the reflash the firmware. There will be a command to commit the settings to flash memory.
For example, my MediaTek 3329 module uses...
The PMTK390 command to save settings to non-volatile flash memory. So you would give a command like...
$PMTK390,0,1,4800,0,1,0,1,1,1,0,0,0,2,9600*38
That would permanently set the baud to 4800. I'd help more if I could, but you'll have to look up the exact settings you want (there's other settings in that command line).
You need 38400 for 5hz navigation and 115200 is more than enough for 10hz navigation.
I would be very wary of using a custom, closed-source binary protocol like the DIY one, lest you brick your unit. I'm not sure it has any real advantage over NMEA or the standard binary protocols anyways.
>Using MiniGPS I can update the firmware, update the refresh rate to 5Hz (no 10Hz option it seems)
Have you put the unit in binary mode? (I do not recall that MiniGPS has the capability to do that.)
The unit has too much data in NMEA mode, it can never output NMEA at 10Hz.
>and switch on WAAS.
That should happen by default.
> None of these options seem to be stored on the receiver though after exiting MiniGPS.
You mean after removing power...
> I've tried the "Write settings into flash" option but this fails.
Because there is no flash.
> What can I do to retain the settings
Keep power applied and/or mod the board to keep the "backup" pin powered.
> and hence get WAAS
It should do this by default
> and the higher refresh rate (5Hz or 10Hz if I can find out how)
Enable binary communication
>to work when I'm connected to the ArduPilotMega?
Program the Arduino to send the commands, decode the received binary data.