Robot locking up using tank drive.

This is our rookie year and i am just learning how to use labview. Whenever i put the robot into teleop mode, it twitches right away and then doesn’t communicate with the joysticks. Here are some attachments of our begin, teleop, finish, and the driver station error message. Thank you!


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That code looks simple and I don’t see an issue. Have you probed the wires from the joysticks going to the RobotDrive? They should also be showing up on the dashboard.

The message about the code not running fast enough could be caused by something not showing maxing out the CPU. Does the charts tab show the CPU usage as being super-high?

If the values going to RobotDrive seem correct, I’d start looking at the electrical. One common issue is that the digital breakout board will not be powered and the motors will sometimes work. You can also put the robot into test mode, enable it, go to the dashboard and click on the test tab, find a motor, select its output value, move the slider and press the motor enable button. This can help to isolate code and electrical issues.

Greg McKaskle

Same thing happened to us sadly. Turned out to be that the sidecar was only recieving 5v instead of 12v. I suggest you should check that.

Alright so we have found what is causing the robot to lock up. We are using 2 victor motor controllers to control the drive motors. However, in beginVI if we open the drive motors as victors the robot locks up. But if we open them as jaguars, it doesn’t lock up. However, when we open up the controllers as jaguars and press button 1 on the joystick. It makes one of the drive motors go forward and one goes backwards while moving the relay in reverse. If we press button 2 on the joystick, it makes the drive motors act the same way except it moves the relay forward Any help would be appreciated.

Here are our updated images.

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Did you check to make sure your Digital Sidecar was receiving 12 volt battery power?

No i have not yet, i will be able to check tomorrow afternoon. Thanks for all the help so far guys, i really appreciate it.

Could the digital sidecar not receiving 12v cause the problem of the robot locking up when we choose victor drive motors in labview (which are the controllers we are actually using).

And are there any noticable errors in my coding that would make the buttons move the drive motors and the relay?

There are subtle technical reasons for Victor and Jaguar PWM signals to give different results if there’s no 12 volt power received by the Digital Sidecar. I could give a plausible explanation for the symptoms you report, but I’d rather spend my time fixing things instead.

Alright, everything is working properly. I would like to thank everyone for their help! It turns out the digital sidecar wasn’t connected properly.