Robotics StackExchange | Archived questions

No motors found!

I am not able to overcome this error for sometime now. There are similar questions but none of them have been able to solve my problem of "No motors found". Here's the error message that ROS gives when I launch the controller_manager.launch file.

PARAMETERS
 * /dynamixel_manager/namespace: dxl_manager
 * /dynamixel_manager/serial_ports/pan_tilt_port/baud_rate: 1000000
 * /dynamixel_manager/serial_ports/pan_tilt_port/max_motor_id: 8
 * /dynamixel_manager/serial_ports/pan_tilt_port/min_motor_id: 1
 * /dynamixel_manager/serial_ports/pan_tilt_port/port_name: /dev/ttyUSB0
 * /dynamixel_manager/serial_ports/pan_tilt_port/update_rate: 20
 * /rosdistro: indigo
 * /rosversion: 1.11.13

NODES
  /
    dynamixel_manager (dynamixel_controllers/controller_manager.py)

ROS_MASTER_URI=http://localhost:11311

core service [/rosout] found
process[dynamixel_manager-1]: started with pid [5276]
[INFO] [WallTime: 1438486858.620549] pan_tilt_port: Pinging motor IDs 1 through 8...
[FATAL] [WallTime: 1438486859.290363] pan_tilt_port: No motors found.
================================================================================REQUIRED process [dynamixel_manager-1] has died!
process has died [pid 5276, exit code 1, cmd /home/ankit/catkin_ws/src/dynamixe

I followed dynamixel_controllers/Tutorials/ConnectingToDynamixelBus tutorial to create the package and the launch file. I have also setup my motor IDs using the Dynamanager software by Trossen Robotics. I've set the baudrate to 1000000 as recommended.

The interesting thing is that I can see my motors when I use arbotix_python (arbotix_driver & arbotix_terminal) nodes with the ls command. Please can anybody help ?

Asked by ankitvora on 2015-08-01 22:46:16 UTC

Comments

Answers

Have you set the ID of each motor? There is a command to do that. If you do not set the IDs to be unique, then you do not see one motor, if multiple with the same ID are connected. Because then they all answer and you would get rubbish I guess.

Second thing could be the Interface, do you use the right interface /dev/ttyUSB<?>

If you have other serial interfaces connected the questionmark could be anything from 0-X.

I would do this: Connect 1 motor only, then check your interface and try it again.

Asked by cyborg-x1 on 2015-08-02 06:15:59 UTC

Comments

Hi Cyborg ! Thanks for your answer. As mentioned, I've set the motor IDs using Dynamanager. I can also see all the motors when I use 'arbotix_terminal' node and 'ls' command. It shows me all 8 motors. This makes me think that IDs are properly set. Could there be some issue with the launch file ?

Asked by ankitvora on 2015-08-02 12:22:19 UTC

Also, as per your suggestion, I just connected a single motor. Using 'arbotix_terminal' node and 'ls' command, I get 1 motor found with correct motor ID. But with the launch file, I'm still not able to detect the motor. Is it something to do with Indigo ? Or some dependencies ? Don't know :(

Asked by ankitvora on 2015-08-02 13:18:27 UTC

That exactly happened for me when I used two motors with the same ID. Maybe you could try adding them one by one and see which motor has a problem with the launchfile

Asked by cyborg-x1 on 2015-08-03 02:28:19 UTC

Not helpful ! None of the motors are recognizable individually :(

Asked by ankitvora on 2015-08-05 19:09:33 UTC

Hmmm, I have two of them here, I see if I find time to test the launchfile, http://wiki.ros.org/dynamixel_controllers/Tutorials/ConnectingToDynamixelBus (it's exactly this one right?)

Asked by cyborg-x1 on 2015-08-06 02:45:56 UTC

Btw, have you checked your port? port_name: "/dev/ttyUSB0" If not remove and plugin your serial adapter, and check what dmesg tells you.

[  563.695820] usb 3-2: FTDI USB Serial Device converter now attached to ttyUSB0

Asked by cyborg-x1 on 2015-08-06 02:47:44 UTC

Yes it's the same launch file. I have my motors connected to arbotix-m controller. Is it because of that ? Is it because of the controller that it reads the motors when I use 'arbotix_terminal' and not when I use dynamixel manager ? So does it mean I have to use the arbotix stack instead ?

Asked by ankitvora on 2015-08-06 06:46:43 UTC

Uhm, is the other software running meanwhile? If that is the case shut the other one down. Only one process can use the serial by time.

Asked by cyborg-x1 on 2015-08-06 07:58:59 UTC

This is what 'dmesg' shows: [ 3960.499326] usb 3-2: FTDI USB Serial Device converter now attached to ttyUSB0

So I think this is fine. And as you said, only one software is running at a time.

Asked by ankitvora on 2015-08-06 18:58:10 UTC

I just copied the file into motor.launch and executed it with roslaunch.

[INFO] [WallTime: 1438994752.248898] pan_tilt_port: Found 2 motors - 2 AX-12W [1, 2], initialization complete.

Asked by cyborg-x1 on 2015-08-07 19:48:19 UTC

I use ROS Indigo, Ubuntu 14.04, Packagemanager. What's your version? Did you compile yourself or package manager?

Asked by cyborg-x1 on 2015-08-07 19:50:40 UTC

I have problem with detecting my servos, I spend many days to solve it, but I failed, please check it out here

Asked by Abdu on 2017-09-27 08:10:29 UTC

I have same issue, did you guys solve it please ??

Asked by Abdu on 2017-10-15 15:52:31 UTC