Servers by jDrones

SITL with custom physics using JSON

I am trying to run SITL with a custom physics model and with JSON interface. I have followed the example given here. My physics model runs separately and using a python application I access the state values and send it as a JSON string to the UDP port 9002.
I referred to the SITL - JSON example in the ardupilot repo.

I launch the sitl instance with the -f JSON:127.0.0.1 flag and my python application runs without any crash. I am also able to read and print the pwm servo output from AP. But I think the data transfer is still not successful and I am unable to use mavproxy to execute any commands.

Note: I am running this on windows - cygwin. I don’t face any issues while running the native sitl. Also I am a beginner so I might have missed some small detail. Any help is greatly appreciated. Thank you.

I see the following message in the file \tmp\ArduCopter.log


Setting SIM_SPEEDUP=1.000000
Starting SITL: JSON
Home: 12.915781 77.644586 alt=920.000000m hdg=0.000000
JSON control interface set to 127.0.0.1:9002
Starting sketch ‘ArduCopter’
Starting SITL input
Using Irlock at port : 9005
bind port 5760 for 0
Serial port 0 on TCP port 5760
Waiting for connection …
Connection on serial port 5760
bind port 5762 for 2
Serial port 2 on TCP port 5762
bind port 5763 for 3
Serial port 3 on TCP port 5763
MKFIFO failed with File exists
MKFIFO failed with File exists
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos

JSON received:
timestamp
imu: gyro
imu: accel_body
position
attitude
velocity

No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
bus.bus=0 address=0x55
bus.bus=1 address=0x55
bus.bus=0 address=0x38
bus.bus=0 address=0x39
bus.bus=1 address=0x38
bus.bus=1 address=0x39
bus.bus=2 address=0x38
bus.bus=2 address=0x39
bus.bus=3 address=0x38
bus.bus=3 address=0x39
bus.bus=0 address=0x38
bus.bus=0 address=0x39
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
validate_structures:489: Validating structures
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos
No JSON sensor message received, resending servos


Servers by jDrones