Message: Out of sync

[harex15]

Hey there,

First of all, very appreciate your work.

After all the dances with the rosserial, I decided to try you code for the encoders odometry. Seems that I followed your instructions, but for some reason, when I launch the node, I getting following:

ubuntu@ubuntu:~/catkin_ws$ rosrun serial_odom serial_odom.py
[INFO] [1591885099.739426]: Serial odometry starting
[INFO] [1591885099.803087]: Publishing odometry: odom
[INFO] [1591885099.817796]: Publishing transform from odom to base_link
[INFO] [1591885099.823555]: Starting on serial port: /dev/ttyUSB1
[INFO] [1591885099.850441]: Reaching for serial
[INFO] [1591885099.851808]: Here are the first 5 data readings ...
[INFO] [1591885101.253790]: Waiting: 0, "B" to start
[INFO] [1591885101.753338]: Debug Mode, full text output
[INFO] [1591885101.757931]: Waiting: 1, "B" to start
[INFO] [1591885102.257105]: Debug Mode, full text output
[INFO] [1591885102.262180]: Waiting: 2, "B" to start
[ERROR] [1591885102.755237]: Out of sync:
2A2A2A4465627567204D6F64652C2066756C6C2074657874206F75747075742A
[ERROR] [1591885102.784368]: Out of sync:
2A0D0A57616974696E673A20332C2022422220746F2073746172740D0A412064

And, then this
[ERROR] [1591885102.784368]: Out of sync:
2A0D0A57616974696E673A20332C2022422220746F2073746172740D0A412064
Running all the time.

I would really appreciate you help.

I'm using:
Ubuntu 16.04
Kinetic
Arduino Mega 2560

Thanks in advance

[EwingKang]

Hello @harex15, I currently don't have the ability to replicate the issue due to the lack of testing hardware and computers. I'll try to set up one in my spare time but it might take some time (maybe up to weeks). Sorry for the inconvenience, I'll keep you posted if there's any update.

[EwingKang]

Giving a closer look, it seems like the Arduino wasn't getting starting command from the host computer, which should be a ASCII "B" (0x42) through the serial port.

The ascii serial output full text output actually maps to
44 65 62 75 67 20 4d 6f 64 65 2c 20 66 75 6c 6c 20 74 65 78 74 20 6f 75 74 70 75 74
,which occures in your "Out of sync" message
Another example is the "Waiting", which translate to 57 61 69 74 69 6e 67 also appears multiple times.
Can you confirm that you
a) Wire the Tx/Rx to the Arduino correctly (or through USB port?)
b) That you have the correct setup for accessing privileges to the serial port in the Linux, I.e. you have correct add the current user to the dialout group.