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Ah that's great. I think i'm going to get my hexapod until its "final" configuration, then check this out. Thanks

Kurt, i'm thinking about getting a rovor as a platform to develop some ROS experience. Are you happy with the Turtlebot3? Would you recommend it vs more home made options? It's only real purpose...

If you're in HS and this is your first robot/hw/sw project this is very impressive!

How did you make your simulation environment?

Have a github we can check out?

Great job!

Yep, it's better than that! :tongue::wink:

Have you sought professional help? Trying to function with a mental health issue is no different than trying to run with a broken leg. You're obviously a...

Update. 5 years later, i've graduated! One class at a time is slow going...

If anyone needs an OpenCM9.04B, i have a one brand new in sealed packaging i doubt i'll get to using. Just send me a PM.

For reference, here is how to use syncwrite using the low level API:


targets = dict()
targets[servo1_id] = m1_goalpos
targets[servo2_id] = m2_goalpos
dxl_io.set_goal_position(targets)

Nope, there should be no slipping for any of the gaits if its working properly. Believe me, i've been spent hours with my head on the floor watching the feet move. hah.

There was once a bug in the...

Hrmm shouldn't do that. the approach from stopped to stepping is simply a scaling of tiny steps. So each step should shrink in height and length from zero to some max size. stopped is actually...

bump for free!

I forget exactly, but basically the step magnitude is in X and Y directions and positive and negative. That defines where the foot is going relative to the "zero" home position...

Look up DH parameters. It's up to you to define the coordinate system for each ridgid part of the robot. If your leg IK does the math in the "leg" coordinate system, then you can relate the leg coord...

That's really cool. I've always been interested in making autonomous cars go fast. I worked on a DARPA Urban challenge team back in the day and we took it to VIR. It went a solid 10mph... ha I also...

Here ya go:


float gama = degrees(atan2(groundY, groundX)) + pi()/2;

You want atan2 so that it operates correctly outside of a quadrant. the +90deg converts it to the format you want, 90deg at...

The good news is is that things can only work better from here!

You have your servos powered up with ~11-12V, right?

Has this hardware setup ever worked?

First, watch your /dev directory and...

You might try the pypot libraries: https://poppy-project.github.io/pypot/index.html

They have a couple options, one is a higher level "controller" and the other is a low level dynamixel API. I'm...

I've had a couple LiPo packs sitting for a couple years... in terms of safety, what should I do with them? attempt to charge? dispose somehow?

Really cool. Great work!

Hi all,

Per some recommendations on here, I started digging into the PyPot project: https://www.poppy-project.org/en/

They offer a pretty solid python library for interfacing with Dynamixels:...

You've all been very helpful to me. If any of you helpful regulars want any of this stuff for free, send me a PM.

I should mention that you have to be in the US.. i don't really want to mess with...

Thanks for the great info.

I've been playing with pypot a bit and it is really great. I've only tested it using the low level dynamixel commands which is equivalent to what i was doing in C, but...

PyPot looks very promising. I'll check it out. Thanks!

Btw, what is the difference between dynamixel protocol 1.0 and 2.0?

Hey guys, how's it been going?

I never really got anywhere with this, but i thought i'd give it a go again. What's the latest on running the USB2AX on a Raspberry Pi in Python?

Is this the best...

Hi all,

FREE!

Robotis OpenCM9.04 Rev B (good for AX servos) - brand new in sealed package

Includes shipping in the US.

Please email me at dan d0t durusky at outlook d0t com if you're...

Read through the comments in some code and discovered the Start button! hah so sensible i didn't even think of it.

Looks like i have one servo who's dead, probably lost his ID, but the rest seem...

Fixed it. Silly permissions. I had to add myself to the dialout group.

Now things seem to launch well. No errors or warnings.




NODES
/
Hexapod_Controller...

Things are moving along and i've roslaunch'ed hexapod-simple. However its not finding my USB2AX. The device has a green light and exists in /dev/ttyACM0. I verified that is the device by unplugging,...

I'm catkin ignoring gazebo and sound. catkin_make results in:
[ 81%] Built target hexapod_msgs_generate_messages_eus
Scanning dependencies of target gait
[ 83%] Building CXX object...

Hey Kevin, I'm installing your hexapod_ros and noticed that gazebo is a dependancy. It's 823mb and looks like a graphical sim. Is this required for a "headless" base install? Can the hexapod robot...

Hey guys, I'm going to document as i go here. It'll be somewhat redundant to other guides, but maybe someone will learn something.

So far i have a MKII hexapod, Raspberry Pi 3, and a USB2AX for...

Thanks, i'll read up and (hopefully) figure it out. I think i'll start a new thread documenting my journey.

Ya know what guys. Life is short and I don't have much time these days. I think I'm going to give ROS a go.

KevinO, I see in your github instructions there are some compiler options specific to...

Oh man. Which Pi was that?

I could switch gears and do my OpenCV in C and keep my old code for the rest of things. I don't find a lot of C OpenCV tutorials though.

Actually, good ol' internet to the rescue. I'm going to try this Python wrapper for the C library:
https://github.com/jthorniley/pyusb2ax

Hi all,

I'm porting my code from C/C++ to Python on the RPi3 for some reason. I thought it'd be fun i guess.

I know when compiling the linux dynamixel SDK, you have to replace the hal.c file...

Thanks all. I'll stick with just the RPi3 until I actually run into an issue. It'll certainly get me going.

Kurt, that is a slick board. I'll certainly consider it for my next build re-do which...

Hi all,

I'm starting a new build of my hexapod and am working on a processing plan/architecture. The hardware is a MKII with AX12 servos.

I currently have some code that I wrote that allows...

Ah, perfect, thanks.

I'm starting to lean against running a subprocessor, at least for now, but this might be a good option. Lot's to think about.

The gait sequencer I wrote uses half sine waves to create an arching step and uses many update points along the step trajectory. It runs at a fixed "frame rate", 30Hz or 50Hz work well. So every 20ms...

Interesting, that makes sense, thanks. Off I go!