Accelerometer Help?
 

I'm trying to use the accelerometer example to see if I can set a specific acceleration rate but everytime I run it over the cRIO it doesn't work. And I don't get the values it shows not even with the manual and 10 people reading it :(

Some help?

Re: Help?
 

When you say "it doesn't work," what do you expect it to do and what does it do instead? How do you have the accelerometer connected? Please give as much detail as possible so that we can all work together to narrow down the problem quickly.

Re: Help?
 

I have the cRIO connected via wireless.
I was expecting that when I ran the .vi I could accelerate and it would show me the rate of acceleration but when I move my joysticks it doesn't do anything at all :(

I left the default settings cause I don't understand what they mean :(

Re: Help?
 

I'd check your wiring first. What ports are the accelerometer plugged into? Is that analog bumper working? Please fully explain your wiring.

What happens when you shake the accelerometer?

The settings indicate the middle point and the sensitivity of the sensor. Basically, they help map voltages to accelerations.


EDIT: Moderators - Can one of you please rename this thread?

Re: Help?
 

A quick build on the last post. Are you using the dashboard? If not, do. This will help you ensure that your accelerometers are indeed working and plugged into the ports you think they are. (The dashboard helped us!)

Re: Help?
 

Does the cRIO have an accelerometer...?

Re: Help?
 

No. The accelerometer is a separate board.

Re: Help?
 

So that means we need to buy one right?

Re: Help?
 

No, one came in the kit of parts. It is a red board that is 1" square that says Accel on it.

It is shown on page 2 of http://usfirst.org/uploadedFiles/200...r%20Manual.pdf

Re: Help?
 

Is it the piece connected on top of the cRIO. Connected to one of the slots?
The Digital one?

Re: Help?
 

No. The Accelerometer came in the padded manila envelope in the KOP and doesn't attach to the cRIO modules.

It needs to be physically wired before it can be attached to anything. It's just a bare 1" square circuit board.

Re: Help?
 

Then we are missing it :( Cause I just went out to look for it and I didn't find it...
I'll keep searching....
After that I guess I'll figure my way out...



Also, I want to set a specific speed to the jaguars but I can't find where to do it.
I used all the motor examples available but none of them save the settings when I use the joystick...Any help?

Re: Help?
 

Someone should have done an inventory of your Kit Of Parts, using the 2009 KoP Checklist on the http://www.usfirst.org/community/frc...nt.aspx?id=452 page (find it under Section 10 - The Kit of Parts). Ask the person who did it whether your accelerometer board was missing, and where it got put if it was included.

I'm not sure I understand what you're asking. What does "save the settings" mean?

Re: Help?
 

Yeah we are actually missing it.
All the teams from PR.

From what I read I can adjust the jaguars right?
I want to set a specific acceleration rate and a specific speed limit.
How can I do it?

Re: Help?
 

You had the chance to tell FIRST about missing KoP items the first week.
You can't "adjust" a Jaguar the way you're describing it. What you can do is control its output, from full reverse to full forward and anything in between.

If you want to limit the maximum output, do it in software with a MIN() function. If you want to have a specific rate of change, do it in software by only changing the control value by a given amount in a given time until it reaches the desired value.

Re: Help?
 

Yeah we sent the report.
Thing is, every single team here in PR received the pack one week later.
So our order will take longer :(

Man I got so lost in the explanation of the jaguar :(
I just want to set a maximum speed so the speed never goes up what we think is the best choice. And if we limit the output then I guess that will be solving our problem. Thing is I don't know how to do it with LV if it's possible.

Which would be that software :S

Re: Help?
 

There are many ways to implement what you want. Here are two simple methods.

The least good way to do it is using the "In Range and Coerce" VI that is under Programming -> Comparison. This will allow you to place limits on what will be sent to the Jaguar. Unfortunately, it is just a hard limit - moving your joysticks beyond that limit will just return the limit. This means that your sensitivity will be awful. I mention this option only because that VI will be useful in other situations.

A better way to do it would be to multiply your joystick value by your intended limit. If you only want 25% speed, multiply by .25 . This will allow you to use the full range of the joysticks.