PX4 work_queue task unable to print out PX4_INFO in nsh?

PX4 Autopilot
1

Hello, I am trying to write a module using work queue task in PX4. I notice that inside the Run() function, PX4_INFO logging system doesn’t seem to print out anything to the nsh but it works fine in the init() function. For example,

bool LedHeading::init()
{
// Run on fixed interval
PX4_INFO(“Test”);
ScheduleOnInterval(1_s); // 1000000 us interval, 1 Hz rate
return true;
}

will print “Test” on the nsh terminal upon starting the module, however

void LedHeading::Run()
{
if (should_exit()) {
ScheduleClear();
exit_and_cleanup();
return;
}

perf_begin(_loop_perf);
perf_count(_loop_interval_perf);

PX4_INFO(“Inside loop”);
perf_end(_loop_perf);
}

will not print “Inside loop” at all… even though it is scheduled to run every second in the init(). I read that work_queue task does not support blocking calls, but PX4_INFO should not be a blocking call??
I am testing this module on a holy bro pixhawk4 hardware.

Thanks!

2

How are reading the print calls? Are you using a console on the debug port?

E.g. through something like this: Pixhawk Debug Adapter – Holybro

3

I am using QGC → MavLink Console via micro usb port in the Pixhawk4

4

Yer, so the work queue is already started and the printfs of it go to the debug console port, and not the console that you are accessing using MAVLink.

I can recommend one of these two options to properly get printfs:

  1. Get a proper debug adapter like the one linked above, or the Dronecode Probe v2.3 JTAG/SWD adapter + USB-UART adapter with DCD-M ca – Zubax Robotics
  2. Set up the console on another serial port and connect an FTDI cable to that output. The list of the serial ports is here: Holybro Pixhawk 4 (Discontinued) | PX4 User Guide, and the setting for the selection of the port is here: PX4-Autopilot/defconfig at 8feb662557f13e385519d039a4c9501b6c885076 · PX4/PX4-Autopilot · GitHub
5

Okay thanks! Is there a way to print to the MAVLink console instead? I don’t have the dronecode probe with me now.

6

You can use mavlink_log and send statustexts.

7

That seems to be good enough for now. Thanks!