Resolved Resolved by Dunning-Kruger!

Servo Movement Panel- Unable To Turn Left Or Right?

So this is a head scratcher one for me. I am still using ARC 2020.01.05.00 first off.  Im trying to get the robots drive system to make left or right turns, but I can only do forward and reverse. I have a EZB-V4, I have a SSC32 to the EZB. Ive tried a DE 2x12RC motor controller and then a Sabertooth 2x15 motor controller. Both exhibit the same results. On the SSC32 I have setup V14 for F/R and V18 for L/R. Here is where it really gets wierd.... when in the test setup mode of the Continueus Movement panel,when i click on the verious test buttons, I can get the proper motor directions, but once I save it and go to use the movement panel, I can get only forward or reverse, no matter which of the four directional buttons i click on. And the real topper.... Ive tried both motor controllers hooked up to a 3 channel RC car system and all directions work perfectly fine. So has anyone dealt with this same issue? Ive used the movement pannel on other robots and never seen this happen before.

Related Hardware EZ-B v4


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#1   — Edited

First off update your software.... I am confused... Why are you using the servo Movement Panel to (I assume) drive your sabertooth? Unless you haven't set your sabertooth to simplified serial yet. So if you haven't... This is what I would do (and have done).. set your sabertooth to simplified serial (9600 baud I find is most reliable) by setting the appropriate dip switches.... Use the sabertooth Movement Panel or download my custom sabertooth Movement Panel example (hopefully it is still floating around synthiam somewhere). To get speed control with my example you can simply use variables in order to adjust speed if need be... Drive your sabertooth directly from one of the ezb's uart ports...  Not sure how the ssc-32 comes in to play here but at least you haven't release the magical blue smoke with your mesh of gobbly goop electronics.... xD


The sabertooth Movement Panel does have speed control :). You can get it here:


Hmm, interesting. Is there a certain model of Sabertooth that works with this control? I happen to have the 2x15RC motor controller. Im guessing from what I have read so far, you only connect the S1 line from the controller to a EZB digital port? and do nothing with the S2 line? Looking at the dispswitch setting on this controller, there is nobaud settings, only a microcontroller mode (dpsw 5&6).  Will this control also work with a Roboclaw motor controller?


I believe you have the 2x12RC, because the 2x15RC doesn't exist on their website. I read the manual for the 2x12RC and it doesnt support serial mode. This means you'll have to sort out how to make PWM mode work with your device. The continuous servo Movement Panel is the best option. Here are instructions to using it:

I recommend configuring the STOP value and enabling it for this controller. I believe the controller will always be happy with a STOP value, rather then the control stopping the PWM.

Here's the manual for your controller. I recommend reading it to ensure the switches are configured as they should. You want the motors to operate independently of each other because the PWM from the EZB will send for each motor.


Ok so you have an RC model of the sabertooth.... try just using the ezb and sabertooth alone separately (for testing)... Configure the right and left channels (ports) and try again.... You may need as @DJ mentioned to adjust the dead zone as the Continuous rotating servo panel is configured for ez robot 360 servos....

#6   — Edited

Yah - configure the "Dead zone" (or called Stop in the control). Also have to set the checkbox that says "use stop value". Thanks for reminding me of the proper working, richard


Thanks guys, thats what I was thinking as well:) I have been trying those ideas as well. I assume that getting that STOP deadband will help in getting the left/right turning to work proper?  Like I said earlier, I can get the forward/reverse and it to stop, just cant get the left/right to work proper. Also, I could not find a write up on how to best use those two sliders, im sure I just missed it somewhere. I will be happy to mark this resolved once I get it operating to my liking:) keep ya posted !


The sliders are the speeds. The left slider is the speed for the left wheel. The right slider is the speed for the right wheel.

If you use a joystick pad, like the one in the user interface builder, set the use variable speed option. Then you can control the speed variably and it’s nicer.


So last night I ordered a new Sabertooth, the 2x12A non RC version. Decided it would be best than trying to get the RC version to work which still wasn't happening for me. So will see what happens next :)


So my newer Sabertooth 2x12 motor controller arrived today. I must say, I am Not impressed with how it works. It pretty much worked like the 2x12RC version. I am using the sabertooth control function, connected to D0, and configured it for 9600, per DE spec sheet. What I found is that whether I am clicking on the arrows or using the speech req, it gives the same results....the two drive motors will sometimes move in sync, sometimes move independent, sometimes ony one side moves. When I go to adjust the sliders, the motors go from slow to fast or the motors will change direction. Sometimes the stop won't work and i have click on the release button to get them to stop. I have had this same result with 9600,38.4k,or 19.2 baud rates also. Also , are there no other controls to adjust in the Sabertooth control?

#11   — Edited

@RoboHappy..... You are not impressed because you either don't understand how it works or you don't have it set up properly.... I have a few non-RC version 2 x 5s and a few 2 x 12s and they all work brilliantly for me.... ARC is flexible so if you can't figure out how the sabertooth movement control works then simple use the custom Movement Panel and write your own...


@DK- I do understand how it works, that is why I am not happy that it is not working correctly for me. I also went back to the servo movement panel( thats the custom one correct?) and could not get anything to operate stable. I did discover that the 38.4k baud setting seemed to work just a little better,  but was still not perfect. Maybe you could show me what you do to get yours to work?, I am baffled with this, it should be easy. I had better luck with those Parallax HB25's way back, which are not made anymore. I do like the Sabertooth, so I really want to get this going, its holding up my big project right now. FYI- I am not using ARC yet, still want to use ARC first.


The servo Movement Panel is not the custom movement panel... The Custom Movement Panel is the Custom Movement script under Scripting... It's a separate control... This is very simple to figure out.... Read the sabertooth manual.... that's how I figured it out... Learn how (and what) to send serial commands (Under the custom movement script)... I won't do this for you or anyone else but I am happy to point you in the right direction. I figured this out myself so you can too.... Besides you will learn and understand a lot more if you do it yourself....


Why is anyone using the custom Movement Panel for the sabertooth? Does the sabertooth control not work well enough?


Yes the built in sabertooth panel works well (last time I used it, anyway). However I personally use the custom Movement Panel because I fully understand the sabertooth and I can fully customize my robot's movement abilities as needed.... Speed control, speed ramping et al....


I was hoping for a more plug n play approach, and no the regular Movement Panel does not appear to work with my sabertooth (hence the reason for this thread in the first place).


hmm - is there anything i can add to the sabertooth Movement Panel that you'd like to see? I hate to think you have to program for something like moving when you could be focusing on programming the robot to do real stuff :)


@RoboHappy: Maybe could help If you provide more information about your setup, e.g. wiring, Sabertooth switches, etc.

Sabertooth hardware is top-notch.

I agree with Richard it seems a "user configuration problem".

#19   — Edited

@DJ I Just checked the built in Sabertooth panel with a 2 x 5 sabertooth.... Yes I configured it properly....  I couldn't get it to work... No direction on the panel worked period.... No movement...  However, my custom panel worked flawlessly.....


Hey guys, sorry if I sounded a lil abrupt earlier, didnt mean too, was just a lil disappointed. I will give the custom Movement Panel a look, since I have nevr used that before actually. Im so use to using the regular Movement Panel which, like i said before worked great on my Cybot which uses the Parallax HB25 motor controllers, so I thought I could go ahead and use the Sabertooth 2x12RC at first. I will use the regular 2x12 controller instead. In the meantime, if the RC version could be made to work with either movement panel, that would be awesome.


Hey guys, thought id give a lil update on my sabertooth control issue. I did in fact try the custom movement panel. After first doing quite a search here on  the sabertooth i find the information on  using the sendserial command. Happy to say, I was pleased to see the motors move the way they should.  I programmed it using the default 38.4K baud rate. Im going to try the 9600 baud setting next, because I noticed that moth motors dont always move together when you speak the commands(but seem ok  when you click the arrows).  I also have it running it at full speed, but I would like to also add half speed, so I am looking at what that will take to do.  Wanna also say thanks for the help and the push. I know Im have more questions soon :-) I click on resolved but it only lets me pick one, when I wanna thank you all :)


More update....:) so tonight I lowered the baudrate in the program to 9600 and I seem to have better control. I would now love to figure out how to get the motors running at half speed now. I  tried moving the speed control  dials and they have zero effect. Again, I am now using the Custom Movement Panel to operate the Sabertooth.  The Sabertooth control itself still does not work for me.


Here’s the Sabertooth Movement Panel and instructions, again:


Hi DJ, I did just that... hate to say it, but no it did not work (the Sabertooth control). Followed all instructions, but only the custom Movement Panel will work, which I am happy for that :-)  Yes I am still using ARC (the very last updated one), haven't gone over to ARC yet, figured id see this work in builder first.

#25   — Edited

EDIT: Deleted. Forget all this. I see you already have covered it. I should read closer. LOL ;)