Error when trying to publish data to a new topic

Hello all

I am working with a 5 hole probe to get the airspeed, alpha and beta of the vehicle . I’m calculating the values using an external micro-controller and sending the data to pixhawk serially . I can read the data at telem port 1 of the pixhawk.

Now I need to publish this data to a topic . I have created a topic in the msg dir named probe_parameters. I have followed the px4_smiple_app example to publish the values I get to my topic.But its giving me an error and I cant figure whats it.
" Built target modules__gnd_pos_control
Built target modules__gnd_att_control
[100%] Built target romfs
Linking C static library libexamples__probe_pub.a
[100%] Built target examples__probe_pub
Linking CXX executable firmware_nuttx
…/…/examples/probe_pub/libexamples__probe_pub.a(probe_pub.c.obj): In function probe_pub_thread_main': /home/ephrem/pixhawk_src/Firmware/src/examples/probe_pub/probe_pub.c:208: undefined reference to __orb_probe_parameters’
collect2: error: ld returned 1 exit status
make[3]: *** [src/firmware/nuttx/firmware_nuttx] Error 1
make[2]: *** [src/firmware/nuttx/CMakeFiles/firmware_nuttx.dir/all] Error 2
make[1]: *** [all] Error 2
make: *** [px4fmu-v2_default] Error 2 "

I’m stuck at this error : " undefined reference to __orb_probe_parameters "

Can someone tell me whats the issue here ? I’m attaching my code too

probe_pub.pdf (61.3 KB)