Humminbird Helix 7 integration

Third Party Products
1

Howdy folks, I am integrating a Humminbird Helix 7 G4 sonar in my Blue Boat, as well as an Emlid M2 RTK GNSS receiver. The main objective is to send RTK GPS data to the Helix 7 (I record the side scan imagery on an sd card on the Helix 7) and to send the depth below the transducer to the Navigator.

I am using Humminbird’s external GPS cable and a Sparkfun RS232 to TTL shifter to connect the Helix 7 to Serial3 on the Navigator.

I have 2 problems:

  1. I successfully connected the RTK GPS to Serial 4, but when I set the GPS2 parameters in QGroundControl I lose GPS lock in QGC but GPS still appears in BlueOS. Losing GPS lock prevents me from arming the Blue Boat. I can disable the GPS arming check but I prefer to figure out how to run both the stock Blue Boat GPS (as a backup) and the M2 simultaneously.
  2. I can send position data from the Navigator to the Helix 7 but when I try to set up the sonar as RNGFND1 on serial 3 using the NMEA output from the Helix 7 then I lose GPS. Serial3 protocol is set to GPS (NMEA is no longer an option) so perhaps this is the issue?

I’ve gone as far as I can with ChatGPT and Gemini. Any thoughts?

2

Hi @nuballawalla -

To setup another GPS with the ArduRover autopilot, you need to configure the correct parameters. Since you have Serial4 (or Serial 3 - you mention both!?) connected to your GPS, which I assume is sending NMEA data? Do you know what messages and at what rate?

Set

Serial#_Protocol to GPS (this documented here)

Serial5_Protocol remains GPS (for standard BlueBoat GPS)

GPS2_TYPE = 1 (Auto)

GPS_AUTO_SWITCH = 2 / “Blend”. Alternatively set to 1 / “UseBest” to only use the better GPS. The better GPS is decided based on the GPS’s self reported accuracy.

If that GPS doesn’t provide the kind of information the documentation mentions, things may not work as desired….

Only GPSs that report position and speed accuracy can be used for blending. All UBlox GPSs provide this extra information while GPSs using the NMEA protocol generally do not.
Normally blending should be done with two GPSs from the same manufacturer because the scaling of the accuracy numbers varies and will lead to favouring one GPS over the other.

The BlueBoat GPS is made by Ublox! Blue Robotics has not tested or evaluated the EmEmlid M2 RTK GNSSlid Emlid M2 RTK GNSSM2 you’re trying to use… You may be forced to use only it’s position data, disabling the stock GPS?