Uxrce_dds_client filled up to 93.1%

PX4 Autopilot
1

I am running PX4 release/1.14 on 6X module.
When checked the status of uxrce_dds_client, I noticed FILLED indicating 93.1%!
Is this normal? What is causing this large amount of FILLED?

nsh> ps
  PID GROUP PRI POLICY   TYPE    NPX STATE    EVENT     SIGMASK   STACK   USED  FILLED COMMAND
    0     0   0 FIFO     Kthread N-- Ready              00000000 000726 000476  65.5%  Idle Task
    1     1 249 FIFO     Kthread --- Waiting  Semaphore 00000000 001224 000292  23.8%  hpwork 0x24000ac0
    2     2  50 FIFO     Kthread --- Waiting  Semaphore 00000000 001576 000860  54.5%  lpwork 0x24000ad4
    3     3 100 FIFO     Task    --- Waiting  Semaphore 00000000 002896 002164  74.7%  nsh_main
    4     4 255 FIFO     Task    --- Waiting  Semaphore 00000000 001232 000548  44.4%  wq:manager
    5     5 100 FIFO     Task    --- Waiting  Semaphore 00000000 001984 000556  28.0%  Telnet daemon 0x38008fd0
    6     3  49 FIFO     pthread --- Waiting  Semaphore 00000000 002024 000780  38.5%  netinit 0
 1865  1865 100 FIFO     Task    --- Waiting  Signal    00000000 003144 001996  63.4%  mavlink_if3 mavlink start -d /dev/ttyACM0
  522     4 251 FIFO     pthread --- Waiting  Semaphore 00000000 002368 001384  58.4%  wq:SPI3 0x81ef424
  587     4 253 FIFO     pthread --- Waiting  Semaphore 00000000 002368 001696  71.6%  wq:SPI1 0x81ef414
 1868  1865 175 FIFO     pthread --- Waiting  Semaphore 00000000 005976 002692  45.0%  mavlink_rcv_if3 0x30028608
 1869  1869 100 FIFO     Task    --- Running            00000000 002000 001484  74.2%  mavlink_shell
 1486  1461 175 FIFO     pthread --- Waiting  Semaphore 00000000 005976 002292  38.3%  mavlink_rcv_if2 0x30017ce8
  591     4 243 FIFO     pthread --- Waiting  Semaphore 00000000 002312 000960  41.5%  wq:I2C4 0x81ef3e4
 1872  1869  49 FIFO     pthread --- Waiting  Semaphore 00000000 002024 000692  34.1%  netinit 0
 1233  1233 100 FIFO     Task    --- Waiting  Signal    00000000 003048 001980  64.9%  mavlink_if0 mavlink start -d /dev/ttyS6 -b p:SER_TEL1_BAUD -m p:MAV_0_MODE -r p:MAV_0_RATE -f -s -x
 1234  1233 175 FIFO     pthread --- Waiting  Semaphore 00000000 005976 002292  38.3%  mavlink_rcv_if0 0x3000e488
 1043  1043 205 FIFO     Task    --- Waiting  Semaphore 00000000 001936 001236  63.8%  gps start -d /dev/ttyS0 -b p:SER_GPS1_BAUD
 1813  1813 105 FIFO     Task    --- Waiting  Semaphore 00000000 001896 001032  54.4%  navigator start
 1302  1302 100 FIFO     Task    --- Waiting  Signal    00000000 003056 001980  64.7%  mavlink_if1 mavlink start -d /dev/ttyS4 -b p:SER_TEL2_BAUD -m p:MAV_1_MODE -r p:MAV_1_RATE -s -x
 1303  1302 175 FIFO     pthread --- Waiting  Semaphore 00000000 005976 002292  38.3%  mavlink_rcv_if1 0x30013238
  600   600 100 FIFO     Task    --- Waiting  Signal    00000000 009880 009204  93.1%! uxrce_dds_client start -t serial -d /dev/ttyS3 -b 921600
  729     4 242 FIFO     pthread --- Waiting  Semaphore 00000000 002216 001196  53.9%  wq:nav_and_controllers 0x81aa544
  730     4 255 FIFO     pthread --- Waiting  Semaphore 00000000 003120 002308  73.9%  wq:rate_ctrl 0x81dfc74
  732     4 241 FIFO     pthread --- Waiting  Semaphore 00000000 005976 004316  72.2%  wq:INS0 0x81ef3ec
  478     4 246 FIFO     pthread --- Waiting  Semaphore 00000000 002312 001024  44.2%  wq:I2C1 0x81ef3cc
  231     4 237 FIFO     pthread --- Waiting  Semaphore 00000000 001872 000888  47.4%  wq:hp_default 0x819bc4c
  744     4 240 FIFO     pthread --- Waiting  Semaphore 00000000 005976 004316  72.2%  wq:INS1 0x81ef3f4
  489     4 245 FIFO     pthread --- Waiting  Semaphore 00000000 002312 000840  36.3%  wq:I2C2 0x81ef3d4
  556     4 252 FIFO     pthread --- Waiting  Semaphore 00000000 002368 001964  82.9%! wq:SPI2 0x81ef41c
  749     4 239 FIFO     pthread --- Waiting  Semaphore 00000000 005976 004316  72.2%  wq:INS2 0x81ef3fc
  752   752 140 FIFO     Task    --- Waiting  Signal    00000000 003192 001492  46.7%  commander start
 1461  1461 100 FIFO     Task    --- Waiting  Signal    00000000 003048 001836  60.2%  mavlink_if2 mavlink start -u p:MAV_2_UDP_PRT -o p:MAV_2_REMOTE_PRT -m p:MAV_2_MODE -r p:MAV_2_RATE -p -x
 1847  1847 230 FIFO     Task    --- Waiting  Semaphore 00000000 003616 002532  70.0%  logger start -b 64 -t
 1850  1847  60 FIFO     pthread --- Waiting  Semaphore 00000000 001144 000388  33.9%  log_writer_file 0x30016cc0
  443     4 229 FIFO     pthread --- Waiting  Semaphore 00000000 001704 001108  65.0%  wq:ttyS5 0x81ef46c
  381   381  90 FIFO     Task    --- Waiting  Semaphore 00000000 001280 000852  66.5%  dataman
 1854     4 236 FIFO     pthread --- Waiting  Semaphore 00000000 003600 002244  62.3%  wq:uavcan 0x819d2dc
  383     4 205 FIFO     pthread --- Waiting  Semaphore 00000000 001896 001028  54.2%  wq:lp_default 0x81a1880

Also for the client status, why it is not receiving any packets?
Is this something makes FILLED up to 93% of buffer?

nsh> uxrce_dds_client status
INFO  [uxrce_dds_client] Running, connected
INFO  [uxrce_dds_client] Using transport: serial
INFO  [uxrce_dds_client] Payload tx: 51743 B/s
INFO  [uxrce_dds_client] Payload rx: 0 B/s
2

Hello,

Today I tested again with different sequence.
Previously start client, agent and offboard control as below

  1. PX4 power on, dds_client auto start
  2. SBC power on, dds_agent start
  3. Host PC, sart off board control

Now I start dds agent first then client as below

  1. SBC power on, dds_agent start
  2. PX4 power on, dds_client auto start
  3. Host PC, sart off board control

Below is the result.
It is clear that dds_client detect the agent and start sending signal.

nsh> uxrce_dds_client start -t serial -d /dev/ttyS3 -b 921600
nsh> INFO  [uxrce_dds_client] synchronized with time offset 1699490247884486us
INFO  [uxrce_dds_client] successfully created rt/fmu/out/failsafe_flags data writer, topic id: 80
INFO  [uxrce_dds_client] successfully created rt/fmu/out/position_setpoint_triplet data writer, topic id: 149
INFO  [uxrce_dds_client] successfully created rt/fmu/out/sensor_combined data writer, topic id: 168
INFO  [uxrce_dds_client] successfully created rt/fmu/out/timesync_status data writer, topic id: 191
INFO  [uxrce_dds_client] successfully created rt/fmu/out/vehicle_attitude data writer, topic id: 206
INFO  [uxrce_dds_client] successfully created rt/fmu/out/vehicle_control_mode data writer, topic id: 212
INFO  [uxrce_dds_client] successfully created rt/fmu/out/vehicle_local_position data writer, topic id: 219
INFO  [uxrce_dds_client] successfully created rt/fmu/out/vehicle_odometry data writer, topic id: 224
INFO  [uxrce_dds_client] successfully created rt/fmu/out/vehicle_status data writer, topic id: 229
uxrce_dds_client status
INFO  [uxrce_dds_client] Running, connected
INFO  [uxrce_dds_client] Using transport: serial
INFO  [uxrce_dds_client] Payload tx: 55252 B/s
INFO  [uxrce_dds_client] Payload rx: 0 B/s

Still no ros2 topic relayed to the client.

After a while later, I keep getting warning messages like these.

nsh> WARN  [timesync] RTT too high for timesync: 16 ms
WARN  [timesync] RTT too high for timesync: 11 ms

Don’t know what this means right now.
Does anyone can take a look at this and check what might be wrong?
Thanks,

3

My guess is that you have connection issues.

It means that the round trip time from the agent to the client is too high to perform proper time synchronization. Are you using a seria to usb adapter?
On my laptop, using a serial to usb adapter, I have RTT up to 20ms. On a Raspberry Pi 4, using the hardware serial and the exact same settings on the flight controller, it reduces to 1.5ms (ten times lower!)

4

Hi @Benja ,
My board’s rx/tx pins are directly connected to the 6X’s rx/tx on /dev/ttyS3.
There is no usb between them.
Are you using the latest stable 1.14.0 release?

5

May I ask which companion computer are you using?

Yes, I tested it on 1.14.0 stable

6

Yes I’m using stable release 1.14.0
I’m using voxl from Modal AI.

7

It seems like manually starting the uxrce_dds_client may cause this issue.
Instead of starting the client in nsh or rc.board_sensors,
setting UXRCE_DDS_CFG and TELEM3 BAUD in PARAM settings will also start the client and have no issue with FILLED buffer as below.

image
image1177×292 108 KB

I think this should also be mentioned in the document as well.

8

That’s interesting to hear, thanks!