Asked — Edited

Vex Jaguar Motor Controller

Hi All, Can the EZ-B v4 be used with the Vex jaguar Motor Controller ? I think maybe yes but would like some feedback about it. Thanks

http://www.vexrobotics.com/217-3367.html


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#1  

I hit the link to have a look at the specs, but it comes up with a "page not found error". It's possible it could work with an EZ-B, but a look at a datasheet would be good to be sure.

PRO
Synthiam
#2  

Yes it will work . It will work in either RS-232 mode (such as the sc-32 controller works), or PWM mode (which simply works as a modified servo movement panel)

#3  

Theoretically yes, it has two operating modes, one of which makes it look like a continuous rotation servo, so that "should" be plug and play with the EZ-B. I say "should" only because the Parallax HB25 controller also should have worked and it took some extra scripting for anyone to get it to work, and the sabertooth controllers also have an R/C mode that should work but doesn't. That being said, it looks from a quick look at the getting started guide that you can adjust the pwm to match the microcontroller, so that should resolve any potential issues. Not all features are supported in R/C mode, the most important one probably bring the ability to use encoders for position control.

It also has a serial mode that supports all features that may be accessible with scripting and either send serial commands on any digital port, or if it is two-way, through one of the uarts. That would take more research. It is rs-232 and the EZ-B is TTL. In some cases they are interchangeable, in others, not.

Alan

#4  

And DJ just made my post irrelevant while I was typing it.

PRO
Synthiam
#5  

alan, your post was far more useful and detailed :)

#6  

That is very good news

Steve G I will try and give you the PDF Datasheet link Vex Motor Controller I hope this works

DJ and Alan thanks for the quick responses. I am still waiting for my EZB 4 so I will read up on scripting and the Sabertooth/HB25 controllers.

Any usefull links or information to help spearhead my progress would be very much appreciated.

I am a Newbie so theres a good chance I will be asking more questions down the line ;)

This is a really cool community

#7  

For HB25, just search the forums. It just uses the modified servo movement panel, but you need to run an initialization script to send it a command (sorry, I don't remember what the command is right now, but a search for HB25 or HB-25 should find it).

Sabertooth has built in control in ARC, but there are also a lot of threads about scripting the commands in a custom Movement Panel to give more control (like ramping hte speed up and down, which the Jaguar appears to provide natively even in R/C mode).

Looks like a good unit, and I see why you want to get one now since they are selling off the backstock before a replacement unit comes out, and $79 for a 40 amp controller is a really good price (although I didn't look to see if that is 40 amp per channel, or just 20 amp per channel, in which case the price is just good, not great....)

Alan

#8  

Here is more on the difference between TTL and RS-232 and why you may need some additional circuitry to make it work in serial mode connected to an EZ-B UART. https://www.sparkfun.com/tutorials/215

Alan

#9  

Hi All,

I spent a lot of time searching the forums and tutorials.

So far I have been able to run the vex forward and backwards but have not been able to get speed control worked out.

There is also a ramping feature on the controller but it looks like it needs some scripting to initiate it even though it says its an auto feature.

I have not found a good step by step walkthrough for scripting servo continuous controls other than super simple controls.

I am trying hard to learn but in this case I think I need to ask for help...Help!

#10  

What script or control are you using to make it go forward/backward?

#11  

Just the continuous servo control on D-0. All references to the modified servo control I find are for the EB-v3. No script being used yet because I am not sure how. Thanks for reply.

#12  

The continuous servo Movement Panel control or continuous servo control?... There is a distinction... You will need the former if you are trying to control 2 motors.... Playing with the servo settings in the control should give you what you want... An alternative is to use the custom Movement Panel and use basic servo script commands for forward, reverse, left, right and stop...

You are going to need 2 ports if you are using two channels/motors (not sure if the Jaguar supports two channels for this method)

Below is just an example of what you might put in the "forward" and "stop" scripts of the custom movement panel... You would use variations of it for left, right and reverse portions of the control this is if you are using an ezb4. It may work with the ezb3 as well


servo(D0,180) # full forward or reverse motor 1
servo(D1,1) # full forward or reverse motor 2


servo(D0,107) # full stop motor 1
servo(D1,107) # full stop motor 2

#13  

I was playing with both the Continuous servo Movement Panel control and the Continuous servo control. I am now looking at the Custom Movement Panel and that looks like the way to go with scripts. I will muck through it till I somewhat understand it then post questions from there. I will play with the joystick and see if that helps. I am using the ezb4 and two Jaguars.

Thanks Richard

#14  

This will work if you are using two Jaguars... I think maybe the custom Movement Panel is the way to go... This way you can use a variables to control speed... Variables are global so you can change the values in other scripts on the fly and the custom Movement Panel will respond immediately to the speed change...


$speed_M_one=180 #full speed
$speed_M_two=1 #full speed


servo(D0,$speed_M_one) #Jaguar 1
servo(D1,$speed_M_two) #Jaguar 2