Tank Drive Code?
 

I'm the lead (student) programmer for team 848. We can't for the life of us get the tank drive system to work. Right now I'll explain what we have in coding and our Screen Caps from our CPU. Right now we have a Tank Drive VI inside the "While Loop" with 2 Open Joystick VIs outside the "while loop." I know that the sole Open Solenoid VI is a problem, but right now I just need the robot in a driveable state. Looking at our screenshots, are there any obvious mistakes that would keep us from driving right now in tank style? I should state that like alot of teams, we are just learning to do anything in LabVIEW and have no prior programming experience whatsoever. Any help is appreciated. Thanks.

Re: Tank Drive Code?
 

You should try using the tank drive example that Labview included.

Re: Tank Drive Code?
 

Have you tried to run the robot on real-time tether?
If you run the dashboard program while your robot is running on real time, you can check your PWM outputs aswell. That way you know if its a programming problem or something else.

Re: Tank Drive Code?
 

I don't see anything wrong with the code. Make sure that you don't have a disabled robot, and describe what you see. Do the buttons respond to the joystick? If you probe the axis wires, do the numbers make sense?

Greg McKaskle

Re: Tank Drive Code?
 

We tried that. When we plug in our IP Address and Deploy/Run, no inputs work at all, as if the VI was blank. This is without changing anything on the Tank Drive Example.vi mind you. We can't understand why it is like it is.

Re: Tank Drive Code?
 

Are you sure that no inputs are working? Probe the joystick axis output values to see if they change as expected when you move the joysticks. If the probes follow the joystick motion, then you've isolated the problem to the outputs, and you can focus your troubleshooting on that part.

The easiest troubleshooting step is to look at your Driver Station display and make sure it says "Enabled" and "Teleoperated", and that it shows a reasonable battery voltage.

Re: Tank Drive Code?
 

Umm, Battery Voltage has always said "0.00" Is that a bad sign? Even when our robot drove, the driver station reported 0 voltage.

As far as probes go. The Probe on the wire from the "Get Axis" VI (the one connected to USB Port 1) reads like it should. the (Y axis reads correctly.) but the probe reports that the input is coming from USB Port 3. Thus no movement I guess...

For the Second "Get Axis" VI (the one connected to USB Port 2) no data is recorded. no matter what we do to the joystick, the probe reports nothing...

Re: Tank Drive Code?
 

This happened to us a couple of times today. Typically, it would be accompanied by some slightly odd robot behavior. Restarting the robot seemed to do the trick, but it was obnoxious to wait for for the blinking to start so we could resume testing.

Re: Tank Drive Code?
 

made sure to close the tank drive vi at the end of the while loop

Re: Tank Drive Code?
 

Not related at all to your error, but down at the bottom of your code (first image) you are setting PWM4 and PWM5 to 255. The pwm outputs this year are NOT like last year's. Last year, it was from 0 to 255, with 0 being full reverse and 1 being full forward. This year, it is from -1 to 1, and I have not yet figured out which one is which for the axes, throttle, or motors.