View Full Version : Phidget Servo Controls and IK

03-20-2009, 10:18 PM
Wow, Ok. It's a good thing my evil SES arm with phidgets does not have a boxing glove on it, else I might instinctively punch it back. lol.

I've been really tired because I was sick for the past three days but I wanted to show my phidget arm moving to a sequence of moves with my phidget servo control.

Certainly, as always, it doesn't go as planned. Of course, This is a hobby programming project so eh, what the heck. It's still fun posting my progress even though it hurts my pride and I humiliate myself in the process :)

Certainly a few things to think about here before I explore the phase of inverse kinematics. Seeing the evil arm that I plan to unleash on a bag of doggy treats misbehaving in action like this does point out a few mistakes that I didn't not originally think of. I do not go into detail of whats going wrong here, however, I'll keep plugging away and get it right soon :(

YouTube - Evil Robot Hand Not behaving

03-20-2009, 11:41 PM
Pretty cool, quick movements! A bit worrisome though, got a few snickers outta the it hitting a few things, and your reactions. Seems it can be a good sequencer.

03-21-2009, 12:27 AM
Yes this is very much out of control at the moment :( However, I'm able to slow it down easily with one line of code. I still have a lot of work to do on it to get it ready to work with sensors and inverse kinematics, but that is the fun part that this hobby provides. ideas provide real solutions to real problems.

I'm glad you got a chuckle out of it, because I did too as you can tell from my silly comments in the video lol.

a few quotes come to mind that help me continue on during the result of my failures, because I tend to be a major drama king at times :

"“Problems cannot be solved by the same level of thinking that created them.”
- Albert Einstein

“Every problem has a gift for you in its hands.”
- Richard Bach

Here is a quick video of me slowing this evil robotic arm down to help me understand what I am doing wrong: (oh, and it's cuts a little bit short because the batteries in my flip camera died.... :( )

YouTube - Evil Robot arm moving. slowing it down a bit

03-21-2009, 11:54 PM
Hey, that is such a cool cool arm. Definitely more responsive than my NXT. How about sharing it with the world live at makeaffinity.com? You can control my NXT arm from your browser.:cool:

04-06-2009, 08:25 PM
- Hello,

I am starting work on another control that will work with my phidget servo controls. The control will draw a 2d representation of a robotic arm and also allow you to move the robotic arm with your mouse thanks to inverse kinematics. I'll be adding functionality that will allow you to double click on certain joints to temporarily lock the their angles, or just drag the end point around freely.

It will be another control that can be dragged to a form. You can then enter properties to hook up each joint to your phidget servo controls that have placed on your form. The movement will be delayed while manually moving it with your mouse just like how the servo control has a delayed position to desired position.

Here is a quick video. Not much to it yet but, I wanted to share a quick video to show what I'm working on. The video shows unavailable and that seems to happen alot here when it has just recently been uploaded. You can double click the video if you have this problem.

YouTube - Phidget Servo Control and IK

04-07-2009, 01:32 AM
Awesome!!! I cant wait to take it for a test spin! Are you coding these controls to work with the .Servo or .AdvancedServo class? or both? your prev videos I saw only demonstrated 4 servos that I remember now I see a fifth, I also want to say I remember you mentioning multiple controllers?

DC Robotic
04-07-2009, 08:51 AM
Very Nice Semicton!

The IK portion looks a lot like the next stage I have envisioned for my project. I have just created my first arm using Dynamixels. Control through USB2Dynamixel and a C# program. Have it moving and "poses" stored in Database. Next I want to develop an IK control method. I checked out your website, COOL. Are you developing in C#? Can you reccomend a starting point for learning simple IK? I have a good understanding of the concepts and the math, but could use some direction in starting to code it.

04-07-2009, 09:20 AM
Can you reccomend a starting point for learning simple IK? I have a good understanding of the concepts and the math, but could use some direction in starting to code it.

hmmm... sounds like an excellent entry to the TRC Tutorial Contest for anyone interested:)


04-07-2009, 11:11 AM
Yeah, IK from the programming end is probably my biggest weakness in the field. I'd like to see an IK for Dummies.

04-08-2009, 08:41 PM
- Hi Nagmier, It supports an unlimited amount of phidget servo controller boards and is very easy to wire them up with no code. This is using the .Servo board. In fact, the first .Servo board released by phidgets is the reason why I first started working on this because the .AdvancedServo was not available and I wanted to see smooooth movement. I have purchased the .AdvancedServo from Trossen, but have yet to test it. If there are problems with the .advanced servo, I will make sure it works before I share it. And, may even re-write it to take advantage of the .AdvancedServo.

Hi DC Robot, yes I'm coding in C#. Gotta love .net!!! WOOT! http://www.societyofrobots.com has a good inverse kinematics tutorial for a robotic arm. Also, when I'm finished here, this will be a full open-source project where you can dig into the code

I still have a lot thoughts of how I'm actually going to present a final GUI and functionality, so this is just a starting point. Keep in mind, these are two separate controls. My intentions are to allow people to use my phidget servo control individually and/or use the IK control individually or, both at the same time, with as little code as possible.

Don't be fooled by a simple GUI. This can also easily be used to simply visually present the state of your servos or robotic arm if you are creating your own code and logic.

Wired up my IK phidget control to my phidget servo control. here is a video of both controls with a Phidget Servo. I also create a sequence of poses for playback.

YouTube - Phidgets Servo Control and IK - 2

04-09-2009, 07:59 PM
LOL ok, so I'm able to control my phidget arm with my mouse and I'm attepting to use my arm as a puppet. I'm having fun... It's the same project that you have seen before.

04-09-2009, 09:00 PM
I think it's sort of lame this post has been combined into one thread with out my participation. Each step I take with my project I post here. Each new thing that I bring here to Trossen has to be condensed to one single post?

04-09-2009, 09:12 PM
I think it's sort of lame this post has been combined into one thread with out my participation. Each step I take with my project I post here. Each new thing that I bring here to Trossen has to be condensed to one single post?

I'm going to be working on many different projects that involve a SES arm.

Will I always be confined to one single thread topic that people have already viewed? People may think I am simply replying to people that post a thread.

I think you just said it best... each step ... with project... singular...

Oh, and note that Tybs only has one thread for Hagetaka.. and posts updates throughout.. its sorta like a nice-flowing story..

If people are actually interested in what you are doing, they read the thread when it updates.. every time.


04-09-2009, 09:25 PM
ok, thanks.

04-10-2009, 01:21 AM
I look for the new posts Semi, and try to read each one. I really like the things you've been working with, and like the updates, as well as being able to easily look back to where you've come from.

04-10-2009, 01:43 AM
, as well as being able to easily look back to where you've come from.

That's one of the advantages to merged threads, and why we do it. It collects a whole project into one place. Another sizable advantage - Google knows how frequently the forum sees new posts, and you'd be amazed at just how frequently they index here (which is why I leave short-term forwarders when I merge threads, to help "unconfuse" Google's spiders).

One of the tasks moderators face is in helping to optimize the forum for search engines. Keeping Google etal happy keeps the index fresh and a fresh popular well-organized index makes our threads easy to find for FreshBlood searching on a particular topic - and that's how we grow.

If someone wants their stuff to be seen, they can try the melodrama route - but in the end they'd be best suited to playing ball and looking at the larger picture.

04-29-2009, 10:31 PM
This post is a video response to Trossens April Fool Day video: (My own video is the second video below the funny April Fools Joke.) YouTube - Dancebot! The low-cost dancing robot!

My SES arm with Phidgets is still learning how to dance! He needs just a little bit more soul fo' sho! Give the lil' robot another 6-12 months and it's gonna be disco fever!!! Give him a few more days, and this lil' robot is gonna be sporting a new yellow jacket, and a long black mullet for head banging!

I just uploaded the video so it says unavailable here. If you see this problem, just double click the video to view it. Seems it takes an hour or two before it works here on the forums as an embedded video.

YouTube - Dancing Robot Arm