View Full Version : [FTC]: FTC Labview questions
Monty Python
09-10-2008, 15:01
So I have seen the training videos online but I still have some questions (and I'm pretty sure for one of the questions I just missed). Where does the HiTech motor bay get plugged into? I thought it was port 1, but I just wanted to double check. Second, when using Labview, I set up something that said move ftc motor. It said that I needed to specify port before I downloaded the program. What does this mean and how do I do it? Also, if anyone has any advice with regards to how the game controller and bluetooth dongle get set up to control the robot in RC mode that would be great. Thanks.
gregsanCHEVY121
10-10-2008, 14:55
We have also had similar problems kind of. We built ourselves a little square bot to mess around with and get some programming ideas and just get used to everything and when we went to program we couldnt get our dc motors to move. we can plug in the lego motors but going through the motor controller we couldnt get anything. Any ideas on what we need to do?
The HiTech motor controller can get plugged into any of the NXT's INPUT ports (I know... seems BTF, but it's just a data port).
You can plug one controller into a NXT port, and then daisy chain more controllers from this to the next. This gives you a lot of expansion.
Whenever the LabVIEW code asks for a "Port" it wants to know which NXT port you plugged into.
I'd stick with Port 1 'cos it's the default in most cases.
The other thing that it asks is what "controller" it is. Here it wants to know which controller in the daisy chain did you connect the motor to. The one that's plugged directly into the NXT is controller '1' and then then next in the chain (if you have one) is controller '2' etc.
In most cases the port and controller will be '1'.
Monty Python
13-10-2008, 17:43
Thanks! I have yet another question though.
So my team set up our robot, we think we have everything wired correctly, we downloaded the joystick code, we charged the batteries, we (think) we set up the bluetooth device and our robot still won't move. Not so much as a twitch. Does anyone have any idea what we might be doing wrong/what to do next?
gregsanCHEVY121
13-10-2008, 20:11
Yet Again my team is having the same problem as you Monty. We thought we had fixed our problem but never has our robot moved. We couldn't make an autonomous that would move our DC motors or a tele-operated that would move the DC motors. We have tried many things and i don't know if we overlooked a simple problem or not.
When debugging the new environment, there are several things you can do to determine what's breaking down.
1) To debug the Bluetooth link and NXT code, you can do something OTHER than move the wheels... try displaying the motor drive value on the NXT display, or BEEP when a button is pressed. Make sure you have a link.
2) To debug the motor drive, you can hook up the motors and just pre program the NXT to turn the wheels. Forget about operator input. Make sure you can turn the wheels.
If you think the wheels should turn, but they don't... check the yellow fuse in the battery cable. Mine blew so there was no power going to the control module.
Another debugging tool is the LabVIEW debug mode. Instead of using the download and run button on the NXT Terminal, try the Debug button. After a few seconds the Labview front panel will become active. You can put some numbers or LED displays on it, hooked up to the internal NXT "wires". I like to display the incoming joystick values and the wheel drive values.
Bottom line, don't try to debug everything at once.... divide and conquor.
Phil.
Monty Python
13-10-2008, 22:46
Thanks so much for the advice, I'll give it a shot at my team's next meeting tomorrow.
Monty Python
14-10-2008, 18:40
So here's what I found out today while working with the rest of my team's programming people (all of this was done with labview). First, we created a labview program that simply moved one motor forward autonomously. Just put in the block that says move FTC motor. Set it up as port 1, controller 1. Set a value for motor power between 0 and 126 (either that or 127, I can't remember which, if you have content help open it will tell you). Set the motor to move both motor A and motor B (you only need one move FTC motor block to do this). Assuming I haven't forgotten anything, this should make the robot move forward. I have attached the code that we used to make our robot move forward. If this code works then you have everything connected right. Once you have accomplished this step, download the code from ftctraining.com that says 2 joystick control (or something like this). Once you have downloaded this code onto your computer and into your robot, open up the FTC controller station (there should be a video that shows how to do this, but the file is in the C drive under lego mindstorms). Once you have opened the FTC controller station, you need to mess around with it a little bit. Enter in your robot's name, turn the station so that it is set to enable, make sure it says tele-operated mode (there are probably some other things that we did that I forget as well). We did not get our bluetooth to work, so using just these steps you would probably need to leave the usb cable that connects the robot to the computer in. There was significant lag with labview, we will likely try robotC at our next practice. Also, the motors may be inverted (likely they will be inverted for the RobotMovesForward.vi or for the teleoperated program). Hope this helps!
ttldomination
14-10-2008, 20:03
My team is currently considering different programming options and what would benefit us the most in competitions. We are currently looking towards RobotC mainly because most of the people on the team are familiar with RobotC.
So, I was wondering if LabView hosts some sort of advantage over RobotC that we should consider?
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