[FTC]: 35's Drive problem

[gdo]

There seems to always be a lag time in my experience.

just a question, are you using a "deadband" in your code like:

if (-10 < joystick.joy1_y1 < 10)
{
motor[motorD] = 0;
motor[motorE] = 0;
}

((I know its a robotC code, but it just to show an example))

I found that it reduced our lag, though did not make it go away. To really slim down the lag, the smaller the routines the robot has to go through, the faster you will get the code to run on the NXT. The NXT isn't extremely powerful, if you overload the processing power with many routines preforming at once, the cycle rate might be reduced.

Something else we found was that RobotC had the smallest lag time in the NXT, followed by LabView, and trailed by NXT-G. I'm not sure why this is, but it is one reason we stuck to the RobotC.

Just try the deadband, it might atleast help with makign sure your robot comes to a stop (because often if you don't have the deadband, the robot won't come to a stop completely).

[KayyPii]

I tried to program a deadband in labview but it didn't really work, and I have yet to get the chance to fix it. But yea, my team will definitely try that.

[wilsonmw04]

Originally Posted by gdo

Just try the deadband, it might atleast help with makign sure your robot comes to a stop (because often if you don't have the deadband, the robot won't come to a stop completely).

That's where we were headed at tomorrow's practice. What concerns me is this: We didn't have this problem with the VEX system. Doesn't the NXT system have a faster CPU than the VEX? It seems strange that we would be taxing this new system with simple drive commands.

[ttldomination]

I doubt the system is experiencing lag. I'm sure there's something with the code.

BTW, the curiosity is killing me, but can your robot score in the center triangle?

[gregsanCHEVY121]

we have similar lag in our robot and we are pretty sure that it is the programming language. one of our mentors is pretty sure that in robotC there will not be as much lag. Also Wilsonmw04 nice robot. does it score into the triangle and how well does it pick up off the ground? we had similar design at the beginning but decided not to use it because we didnt think it would pick up well and we had other ideas.

[Monty Python]

Make sure you've updated labview. They said there was an error with the move motors vi that would cause the lag.

[KayyPii]

I have all the updates but I'm still experiencing lag.

[wilsonmw04]

Originally Posted by Monty Python

Make sure you've updated labview. They said there was an error with the move motors vi that would cause the lag.

We installed both updates from NI site. I double checked the installation process and everything was done correctly. Are there any other updates that I'm not aware of?

[ttldomination]

Your best chance now would be to try and hook with someone at NI to get some help and try and figure it out.

[wilsonmw04]

Originally Posted by ttldomination

Your best chance now would be to try and hook with someone at NI to get some help and try and figure it out.

posted:
http://decibel.ni.com/content/thread/1772?tstart=0

let's see what happens.

[gdo]

Originally Posted by wilsonmw04

That's where we were headed at tomorrow's practice. What concerns me is this: We didn't have this problem with the VEX system. Doesn't the NXT system have a faster CPU than the VEX? It seems strange that we would be taxing this new system with simple drive commands.

The NXT is faster, I think the lag has as much more to do with the bluetooth. I found that it was better to incorporate FEWER interface commands, where the code looks for the joystick commands, which definately has a slowing affect.

There are more factors, but the bluetooth speed is the biggest problem I think.

I have had very few problems with the bluetooth interface in RobotC, but I haven't been using the FTC Control station, but the included software in RobotC. It will be interesting to see what the robots will do at scrimages with the competition setup. (the only scrimage I went to, people used personal laptops and all used RobotC)

[Lowfategg]

Originally Posted by gdo

The NXT is faster, I think the lag has as much more to do with the bluetooth. I found that it was better to incorporate FEWER interface commands, where the code looks for the joystick commands, which definately has a slowing affect.

There are more factors, but the bluetooth speed is the biggest problem I think.

I have had very few problems with the bluetooth interface in RobotC, but I haven't been using the FTC Control station, but the included software in RobotC. It will be interesting to see what the robots will do at scrimages with the competition setup. (the only scrimage I went to, people used personal laptops and all used RobotC)

I can't see why it would be the blue tooth. They use blue tooth in a number of things (my Wii comes to mind), and they don't have laggy controls, it must be something in the code.

[Monty Python]

Bluetooth is not the problem. My team used to use Labview and there was lag even when using a USB. Also, the bluetooth was not a problem at the scrimmage I attended. Redownload the last Labview update as I'm not sure if they posted a new update, they may have just edited an old one (although I'm not 100 percent positive, this is just what I remember reading is one of the links on chief delphi). Labview had a ton of lag for us and RobotC has almost none. I would suggest trying to run the sample joystick code for RobotC and seeing if you have lag.

[willson.thomas]

Originally Posted by Monty Python

Bluetooth is not the problem. My team used to use Labview and there was lag even when using a USB. Also, the bluetooth was not a problem at the scrimmage I attended. Redownload the last Labview update as I'm not sure if they posted a new update, they may have just edited an old one (although I'm not 100 percent positive, this is just what I remember reading is one of the links on chief delphi). Labview had a ton of lag for us and RobotC has almost none. I would suggest trying to run the sample joystick code for RobotC and seeing if you have lag.

I would agree that it shouldn't be the bluetooth, unless it is the software implementation of it. I use a bluetooth mouse with my notebook and while hardcore gamers tell me there is some lag, I definitely haven't noticed it.

[ttldomination]

Well...we're not exactly running mouse from this. Idk, let's wait for an reply from labview.