Communication Problem Between SITL and Gazebo

Hi, I have set up SITL on my QGroundControl. I need to provide communication between SITL and Gazebo. However, I encounter some issues while connecting QGroundControl with Gazebo. I can run QGroundControl with SITL, but when I enter “sim_vehicle.py -f gazebo-bluerov2 -L RATBeach - -out=udp:0.0.0.0:14550 - -console” the communication can’t be done wit+h gazebo and also I lose communication between QGroundControl and SITL. I have “link 1 down” on the console as an output.
As far as I figured, the ‘-f’ option in ‘sim.py’ is causing the problem.

The output for SITL:

SIM_VEHICLE: Start
SIM_VEHICLE: Killing tasks
SIM_VEHICLE: Starting up at [33.810313, -118.393867, 0.0, 270.0] (RATBeach)
SIM_VEHICLE: WAF build
SIM_VEHICLE: Configure waf
SIM_VEHICLE: “/home/kedy/ardupilot/modules/waf/waf-light” “configure” “–board” “sitl”
Setting top to : /home/kedy/ardupilot
Setting out to : /home/kedy/ardupilot/build
Autoconfiguration : enabled
Setting board to : sitl
Using toolchain : native
Checking for ‘g++’ (C++ compiler) : /usr/lib/ccache/g++
Checking for ‘gcc’ (C compiler) : /usr/lib/ccache/gcc
Checking for c flags ‘-MMD’ : yes
Checking for cxx flags ‘-MMD’ : yes
CXX Compiler : g++ 9.4.0
Checking for need to link with librt : not necessary
Checking for feenableexcept : yes
Enabled OpenDroneID : no
Enabled firmware ID checking : no
GPS Debug Logging : no
Enabled custom controller : yes
Checking for HAVE_CMATH_ISFINITE : yes
Checking for HAVE_CMATH_ISINF : yes
Checking for HAVE_CMATH_ISNAN : yes
Checking for NEED_CMATH_ISFINITE_STD_NAMESPACE : yes
Checking for NEED_CMATH_ISINF_STD_NAMESPACE : yes
Checking for NEED_CMATH_ISNAN_STD_NAMESPACE : yes
Checking for header endian.h : yes
Checking for header byteswap.h : yes
Checking for HAVE_MEMRCHR : yes
Configured VSCode Intellisense: : no
Checking for program ‘python’ : /usr/bin/python
Checking for python version >= 2.7.0 : 3.8.10
Checking for program ‘python’ : /usr/bin/python
Checking for python version >= 2.7.0 : 3.8.10
DSDL compiler : /home/kedy/ardupilot/modules/uavcan/libuavcan/dsdl_compiler/libuavcan_dsdlc
Source is git repository : yes
Update submodules : yes
Checking for program ‘git’ : /usr/bin/git
Checking for program ‘size’ : /usr/bin/size
Benchmarks : disabled
Unit tests : enabled
Scripting : enabled
Scripting runtime checks : enabled
Debug build : disabled
Coverage build : disabled
SITL 32-bit build : disabled
Checking for program ‘rsync’ : /usr/bin/rsync
‘configure’ finished successfully (0.722s)
{‘waf_target’: ‘bin/ardusub’, ‘default_params_filename’: ‘default_params/sub.parm’, ‘model’: ‘gazebo-bluerov2’, ‘sitl-port’: True}
SIM_VEHICLE: Building
SIM_VEHICLE: “/home/kedy/ardupilot/modules/waf/waf-light” “build” “–target” “bin/ardusub”
Waf: Entering directory /home/kedy/ardupilot/build/sitl' Embedding file locations.txt:Tools/autotest/locations.txt Embedding file models/Callisto.json:Tools/autotest/models/Callisto.json Embedding file models/plane-3d.parm:Tools/autotest/models/plane-3d.parm Embedding file models/plane.parm:Tools/autotest/models/plane.parm Embedding file models/xplane_heli.json:Tools/autotest/models/xplane_heli.json Embedding file models/xplane_plane.json:Tools/autotest/models/xplane_plane.json Waf: Leaving directory /home/kedy/ardupilot/build/sitl’

BUILD SUMMARY
Build directory: /home/kedy/ardupilot/build/sitl
Target Text (B) Data (B) BSS (B) Total Flash Used (B) Free Flash (B)

bin/ardusub 3480036 140477 202824 3620513 Not Applicable

Build commands will be stored in build/sitl/compile_commands.json
‘build’ finished successfully (1.498s)
SIM_VEHICLE: Using defaults from (…/Tools/autotest/default_params/sub.parm)
SIM_VEHICLE: Run ArduSub
SIM_VEHICLE: “/home/kedy/ardupilot/Tools/autotest/run_in_terminal_window.sh” “ArduSub” “/home/kedy/ardupilot/build/sitl/bin/ardusub” “-S” “–model” “gazebo-bluerov2” “–speedup” “1” “–slave” “0” “–defaults” “…/Tools/autotest/default_params/sub.parm” “–sim-address=127.0.0.1” “-I0” “–home” “33.810313,-118.39386700000001,0.0,270.0”
RiTW: Starting ArduSub : /home/kedy/ardupilot/build/sitl/bin/ardusub -S --model gazebo-bluerov2 --speedup 1 --slave 0 --defaults …/Tools/autotest/default_params/sub.parm --sim-address=127.0.0.1 -I0 --home 33.810313,-118.39386700000001,0.0,270.0
SIM_VEHICLE: Run MavProxy
SIM_VEHICLE: “mavproxy.py” “–out” “127.0.0.1:14550” “–out” “127.0.0.1:14551” “–master” “tcp:127.0.0.1:5760” “–sitl” “127.0.0.1:5501” “–out” “udp:0.0.0.0:14550” “–console”
Connect tcp:127.0.0.1:5760 source_system=255
Loaded module console
Log Directory:
Telemetry log: mav.tlog
Waiting for heartbeat from tcp:127.0.0.1:5760
MAV>

The output for Gazebo:

Loading freebuoyancy_gazebo plugin…
Loaded freebuoyancy_gazebo plugin.

I couldn’t understand the problem. How can I solve this issue?

Hi,

I would recommend to have an udp output dedicated to QGC, 14550 is probably being used by gazebo already.