robocan and ros

Hello,

I am using this github.com/ecostech/roboteq_diff_driverpackage package to control one single sdc 2130.

So far, the package is working well for me as it allows the controller to subscribe to the cmd_vel topic in ros to generate the necessary linear and angular velocities for my mobile robot.

My next step is to combine 4 sdc2130s together to control 8 motors for an 8x8 robot. I would like to control one sdc2130 as I have been doing with the package and I'd like the other 3 sdc2130s to follow and copy the behaviour of the one that I am controlling. For example, if I ask one sdc2130 to go full speed forward, I want the other 3 to also do the same.

Can someone provide me some suggestions on how to achieve this? I have read about robocan, is this what I should use? How do you set up robocan to achieve this?

Thanks,
Aaron

If I remember correctly, this ROS package is communicating with an SDC2130 over serial in order to send data to the controller, which is interpreted by a microbasic script and sent to the motor controller using one of our control commands.

RoboCAN allows you to call controller commands from any RoboteQ device on the same CAN network by providing it's node ID. The methods to do this are documented in section 16 of our User Manual .

You should treat the controller that is driven by your ROS package as a master device that sends motion commands to your slave controllers on the CAN network. All you should have to do is find where the G command is being called that submits the motor command to the controller, and add 3 more calls to your other controllers at their CAN node ID.

Thank you for your response.

I read in the manual that "Important notice: On many controller models, CAN and USB cannot be operated at the
same time. Please see product datasheet to verify if this is the case on the model used."

Is my sdc2130 effected by this?

I am connecting one sdc2130to my laptop (with usb) which is what is providing the cmd_vel signal to control the motors. I would like 3 other sdc2130 to simply copy what this one is doing.

It should depend on the board revision. Here is a way that you can check:

1) Go to the console tab in Roborun+
2) In the Out Data section, send the command ?UID 1
3) Check the number you get as a result.

If the result you get is 300, then you should be able to use CAN and USB at the same time.If it isn't, let me know and I will check for you. Any controller purchased recently should have this 300 value. This should be consistent across board revisions, which will be listed on the bottom sticker of your controller.