
Mickey666Maus

Hey there, I am having an issue with my robots movement here. I build a litte Lego robot consisting of 10 micro servos, they are supposed to have a 4.8Volts input.
http://www.servodatabase.com/servo/towerpro/sg90
But since I just bought a power supply with a fixed Voltage output, I am putting 6Volts in for this is as far as I can lower the Voltage on this particular power supply...they should be able to take up to 8.4Volts I read!
I made an animation cycle using the AutoPostition in ARC and the movements are pretty smooth...but after a little while the whole motion becomes choppy and erratic.
The power supply is a 7.5v 20 amp switching supply that I found with the help of @SteveG, so the servos should be getting enough Amps!
What could be the problem? I had some Wifi connectivity problems with the EZ-B lately...could it be a problem of data transmittance, or is this some issue with AutoPosition in general?
My board is not having any brown outs so I guess power is supplied at any times!
Where would I start searching for my mistake here?
Thanks for the info....So the flooding would be an option to test the stable animation to check if it will get choppy once the channel is flooded, right?
It is not a problem of the servos interferring with the Wifi I guess, it also happens when I hook up the original EZ-Robot HD servos...
I will try to move the robot, and let you know if it will make a difference... I am off now for a couple of hours but will make further testing asap!
sounds good. I have been up all night monitoring the move of a data center, which just wrapped up. I think I am going to go get some sleep for a while. I will check back later in the day. With me when a problem exists, my brain wants to keep working on it, so if I think of anything I will let you know.
Good luck!
If your want to test the Step, Delay, Speed settings you can use the frames you've set up in AutoPosition in an EZ Script. Adding more then one frame inside a EZ Script will create an Action (Just like inside the AutoPostion Control). You may find this approach easier to set the timing then using the Action section of the AutoPosition control. I am using this approach because I get better results when running DC motors and activating other EZ Scripts in tandem with the AutoPosition frames. I know that the AutoPosition control has places to start outside scripts but I found I had more control and better timing results by calling the AutoPostion frames and other scripts from inside a EZ Script.
Here's how: *Add a EZ Script control through the Menu bar; Projuct - Add Control. *Open it and click on the Cheat Sheet Tab on the upper right. *Scroll down till you find the frames you've made in Auto Position *Find the frame you want to use but it needs to have "AutoPositionFrame" in the center of the command. *Double click to add it the the script. *After you add the command you will see at the end the Step, Delay, Speed settings in brackets. Replace these with your timing settings as DJ described in an earlier post. Do not use the brackets. *You can sprinkle other ControlCommands among the AutoPositionFrame commands to get other things to work on your robot.
Hope this helps.
Thanks a lot for these explicit instructions Dave! I will try to use your approach...this might be a good idea because it also excludes the Auto Position control and might be a way to check where my problem might be!
Will be back home in an hour...can't wait to try out the ideas you threw in here!
I have some of the same servos you have and I have to say they never really worked well at holding position... I think maybe your problem is cheap servos... Sometimes Occam's Razor rules...
RR has some good advice. It could be as simple as creepy servos. However you may not know until you get the timing of the autopositioner dialed in. How do they run individualy if you set one or two through an ez script?
BTW, the method I laid out above does not exclude the autopositioner. It uses the AP control to execute AP frames individually and sets the timing pramitors from outside the AP control.
Back home now and on it...to have even more exclusion for anything that might cause problems, and also just to stay within the system that we are all ensured that it should work, I changed the setup. I unplugged my robot and for testing it's now just my EZ-B v4 with one EZ-Robot HD servo attached!
I just put a simple Auto Position animation just from a 1 to 180 movement which repeats, all settings on the Auto Position are default! It plays the animation and I am having the same jumpy servo movements as before!
I was also thinking that it might be a good idea to attach one of those continuous rotation servos for testing, but I guess this does not do anything to read disconnects, it keeps rotating when the HD servo gets jumpy!
I changed the mode from ap to client so now the router is also further away from the robot, and I moved the laptop of the desk too!
I will now try the approach that Dave was pointing out, but it is still kind of awkward that the jumpy servo problem persists...cross your fingers for my guys!
Any clues on how this could be solved would be great!
DAVE YOU ARE THE BEST!
Got it working...


It took a little while to understand how this whole thing works, but being able to change the settings of the AutoPosition within EZ script I tweaked them for a bit and found out that the DELAY values messed up the movement and this caused the servos to get jumpy....so my Wifi connection seems to be OK and now I will plug my robot back in and check if I can tweak the motion so it will run smoothly!
Thank you guys for staying with me and guiding me thru this! All of you were a great help, I am happy this is solved so I can keep on bringing my little K8 to life!
:Start Sleep(1000) ControlCommand("Auto Position", AutoPositionFrame, "Down", 0, 10, 0) Sleep(1000) ControlCommand("Auto Position", AutoPositionFrame, "Up", 0, 10, 0) Goto (Start)
:D