SLCan Mode Not Working

Hi. I have followed the instructions to use the SLCan feature to upgrade the firmware of my HERE 3 as it is behaving strangely after the latest HERELINK firmware update.

I NEEED things to work when powered on… I unfortunately CANNOT unplug and replug the GPS every power cycle because the system is sealed for water tightness and I work in the jungle doing research. This issue is uniquely new after upgrading HERELINK firmwares and FC arduplane to 4.1.1.


  1. Everything is powered on
  2. The GPS does have to be unplugged after booting FC and replugged but then at least comes on and begins functioning normally with yellow then green flashing lights.
  3. I first connect the FC to MP then go to optional > UAVCAN > then click SLCan 1 and it tried to connect then goes silent/blank.

Then nothing happens… constantly. I only have one GPS and cannot get the device to show up.

Do try Cport and set as 1

I have never had success with MissionPlanner when it comes to UAVCAN. I always use the UAVCAN GUI. Try that.

Thanks. for the reply. I was hesitant to use UAVCAN GUI because after reading the README file it claimed it was not compatible with UAVCAN 1.0 so I never tried it for fear of corruption or something.

I will go ahead and give it a try if people are having success.

To quote the README exactly:

Yes, but Ardupilot is still UAVCAN v0.

Ok perfect. Thank you. I was unsure of this.

Here is how to get SLCAN working on Cube Orange. It is a totally different process and I finally got it working in Mission Planner…

  1. Do not connect with MAVLINK first. Also, restart Mission Planner.
  2. Connect the Cube Orange with the USB cable.
  3. Then go to Device Manager and find COM port on the Cube Orange that is for SLCan.
  4. Select this COM port in Mission Planner, but do not connect.
  5. Go to the UAVCAN page in Mission Planner. Click the SLCan Mode CAN1 button.
  6. A dialog box will open up - it says you might be doing things wrong, but it is fine - click OK.
  7. You should be connected to the GPS.