Configuring Zubax with Pixhawk

Hey Guys,

So I did some fiddling around with the Zubax and my Pixhawk. On the flight controller QGroundControl it reads up my Pix with the Zubax GPS. When connect to Mission Planner it reads as NO GPS. Anything easy I am missing? I have played with the GPS Parameters in Mission Planner a bit, but I am not sure what is going on. The only thing I can think of is that it is not looking in the CAN port for a GPS and rather sees there is nothing in the GPS port and assumes no GPS. Help would be appreciated.

Thanks,
Joe Douglas

Hi Joe,

Please make sure that:

  1. …the Pixhawk firmware is recent enough - as I wrote in the email the other day, the UAVCAN support is available in the stable branch since September 25, 2014. If your firmware is older, you should update it via QGroundControl.
  2. …the UAVCAN driver in PX4 is enabled - the parameter UAVCAN_ENABLE should be set to 1.
  3. …CAN bus is working - the CAN1 or CAN2 LED should be blinking or glowing steadily (assuming that Zubax GNSS is connected to Pixhawk and the UAVCAN driver on Pixhawk is activated).
  4. …your Zubax GNSS has a GNSS fix - the PPS led should be blinking.

If it still doesn’t work, open nsh, execute uavcan status and post the results here.

[quote]1. …the Pixhawk firmware is recent enough - as I wrote in the email the other day, the UAVCAN support is available in the stable branch since September 25, 2014. If your firmware is older, you should update it via QGroundControl.
2. …the UAVCAN driver in PX4 is enabled - the parameter UAVCAN_ENABLE should be set to 1.
3. …CAN bus is working - the CAN1 or CAN2 LED should be blinking or glowing steadily (assuming that Zubax GNSS is connected to Pixhawk and the UAVCAN driver on Pixhawk is activated).
4. …your Zubax GNSS has a GNSS fix - the PPS led should be blinking.[/quote]

Alright here is where I think my issue is. The QGround Control Firmware has the UAVCAN_ENABLE Parameter I need. If I use that software I am not able to connect to Mission Planner which is a must. If I use the Firmware from Mission Planner there is no UAVCAN_ENABLE Parameter. So it looks like I would need to modify the firmware I pull from Mission Planner. Were you ever able to connect to Mission Planner and use the Zubax GPS?

OK, now I see what your issue is - you’re using APM firmware (from Mission Planner), not PX4 (from QGroundControl). Unfortunately, the latest release of APM does not support UAVCAN sensors yet.

However, if you can tolerate the use of unreleased software, you can try this branch: github.com/hsteinhaus/ardupilot/tree/px4gps - it implements UAVCAN support needed to work with Zubax GNSS (only GNSS data though; barometer and compass aren’t supported yet).

Ahhh I understand. Thanks for the help and the links!

Hi Pavel,

I am in a similar position. I have received the GNSS tonight and have attempted to connect it to my Fixhawk. I must admit I am not familiar with a lot of the configuration instructions in your tutorials and am a bit lost. I have flashed the flight controller with the native Pixhawk firmware from QGroundControl and have set the CANBUS parameter to 1 as described. I have connected the GNSS module and have the CAN1 LED activated.

Is that it, am I ready to calibrate and then fly?

Do I need to use the terminal plug that was supplied?

Do I need to configure the GNSS with a CLI as indicated in the tutorial. I did try going through that process but was unable to make any sense out of Putty and really struggled.

Looks like a great board. Thanks

Hi,

Sorry for responding lately!

[quote]I have received the GNSS tonight and have attempted to connect it to my Fixhawk. I must admit I am not familiar with a lot of the configuration instructions in your tutorials and am a bit lost. I have flashed the flight controller with the native Pixhawk firmware from QGroundControl and have set the CANBUS parameter to 1 as described. I have connected the GNSS module and have the CAN1 LED activated.

Is that it, am I ready to calibrate and then fly? [/quote]

Seems so, yes.

Yes, absolutely. Please note that the tutorial explicitly instructs you to insert the termination plug into another connector of the same CAN interface that you connected your cable to. In other words, if the cable is inserted into one of the CAN1 connectors, the plug goes to another CAN1 connector, and both CAN2 connectors remain unused.

Sorry to hear that. In fact, the current Pixhawk firmware allows you to use Zubax GNSS as-is, no configuration required, but beware that this may cause problems if you connect more than one UAVCAN-powered device to Pixhawk.

BTW, we’re going to release a nice cross-platform GUI application for device configuration soon, so our users won’t have to tinker with CLI anymore.

Pavel.

Fantastic, thanks Pavel. One last question. How long should it take to get a GPS fix when the device is first used? I’m in Southern Hemisphere if that makes any difference.

Depends on the conditions. Usually it takes under 40 seconds under clear sky.

Pavel.