| View previous topic :: View next topic |
| Author |
Message |
trevarthan
Joined: 17 Oct 2006
Posts: 48
|
 Posted: Tue Oct 17, 2006 5:11 am Post subject: Introduction: Jesse Guardiani |
 |
|
INTRODUCTION
=============================
Hello,
Ginge/Barry, Dale, I'm also a fellow Linux guy! In fact, I used to work as a Sys Admin at a local ISP. I think Dale Weber (linuxguy) mentioned FreeBSD. Yeah, me too. But these days I much prefer linux.
I work a day job as a professional web programmer, and I got my start doing C/C++ and 2D/3D games in high school (1998-ish?)
I've been itching to build a robot since I was about 3 years old. No kidding. Knight Rider on that crappy black and white TV really messed me up for life. And I think I've finally got the resources to do it.
At first I thought I'd build a hexapod, but then I backed down to a quadropod because they're cheaper. Now I'm thinking I'd like to build a robo-one style bot. And I'd like to do it in a way that I can strip it down and make something else out of the parts when I'm done (otherwise why the heck did I waste my time, right?)
I don't have a machine shop (though I'm quickly collecting friends with machine shops and CNC mills in their basements/sheds) and I don't intend to unless I get incredibly rich soon (not likely). So I'm seriously considering lego technics for the prototype bots. I've got a massive stock pile from childhood and they're perfect because I can re-use them. Strength and bulk being the only issues, but we'll see how it goes. Just got to drill out the servo paddles to fit the pegs.
I've got 3 years of CAD experience from high school not all that long ago. And I've sort of kept it going with Blender3D (though precision isn't in Blender's vocabulary).
I've got some Basic Electronics Theory under my belt and a few escapades with 555 timers and the like, but ultimately I'm a software guy. And I intend to become a 900 lb software gorilla on this one.
My intended hardware platform will be Gumstix because it runs Linux. But I'm still not sure what to buy and when. I have to space my purchases out over the course of several months at best. And I'd like to include WiFi and a web cam with my robot, but gumstix lacks USB host support. However, I have the unofficial word of a gumstix rep that they will be releasing a new board in the next 6 months or so with USB host support. So I'd like to hold off on an embedded platform purchase till I'm nearly done with the project.
QUESTIONS
=============================
1.) ginge, do you intend to release that linux code as GPL?
2.) OpenServo uses I2C. So what do I need to connect an OpenServo I2C bus to my Intel I2C header on my motherboard? Will that work? If not, what do you folks recommend?
3.) Also, I need to purchase at least one servo to get started. I'm eyeing the Futaba S3305:
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDWF8&P=ML
But I don't see that servo listed as supported hardware. What are the chances that it will work? What are the likely road blocks? Form factor? IC hardware?
4.) Do I really need to buy a programmer? Or can I buy pre-made, pre-flashed boards from one of you folks and stick to C API development?
Thanks! |
|
| Back to top |
|
 |
linuxguy
Joined: 16 Oct 2006
Posts: 120
Location: Beaverton, OR
|
| Posted: Tue Oct 17, 2006 7:09 am Post subject: Re: Introduction: Jesse Guardiani |
|
|
| "trevarthan" wrote: | INTRODUCTION
=============================
Hello,
Ginge/Barry, Dale, I'm also a fellow Linux guy! In fact, I used to work as a Sys Admin at a local ISP. I think Dale Weber (linuxguy) mentioned FreeBSD. Yeah, me too. But these days I much prefer linux. |
Welcome!
I just arrived here a few days ago myself, although I have been watching Open Servo for awhile now. I enjoy tinkering with Linux, but my server runs FreeBSD 6.0 and I am now hosting one of my own websites and doing primary DNS for that domain.  As soon as I get mail up and running, I am taking another of my domains in house here.
| "trevarthan" wrote: | | I work a day job as a professional web programmer, and I got my start doing C/C++ and 2D/3D games in high school (1998-ish?) |
We may have a very similar background although I seem to be much older than you. I graduated in 1976. I always took every electronics and computer course in high school that was offered and always did well.
| "trevarthan" wrote: | | I've been itching to build a robot since I was about 3 years old. No kidding. Knight Rider on that crappy black and white TV really messed me up for life. And I think I've finally got the resources to do it. |
I know the feeling, since I have wanted to work with robotics ever since I was in junior high school. I can't remember what actually got me on this track though, but it sure did stick.
| "trevarthan" wrote: | | At first I thought I'd build a hexapod, but then I backed down to a quadropod because they're cheaper. Now I'm thinking I'd like to build a robo-one style bot. And I'd like to do it in a way that I can strip it down and make something else out of the parts when I'm done (otherwise why the heck did I waste my time, right?) |
I am specializing in Octapods and Hybrids (wheels and legs). Oh, I am going to build a Hexapod first, because there is so much software available for them. I am using the Lynxmotion Servo Erector Set for my prototyping. Lynxmotion has 3D CAD models of all their parts, so I can use those to design my robots and check them out well in 3D before I actually start building.
[quote=""trevarthan""]I don't have a machine shop (though I'm quickly collecting friends with machine shops and CNC mills in their basements/sheds) and I don't intend to unless I get incredibly rich soon (not likely). So I'm seriously considering lego technics for the prototype bots. | Quote: |
I would love to have a friend with a nice machine shop! Check out the Servo Erector Set before you commit to using any specific kit of parts or for later use. You can see all the 3D CAD models I have created, using their parts models, on my website.
[quote=""trevarthan""]I've got 3 years of CAD experience from high school not all that long ago. And I've sort of kept it going with Blender3D (though precision isn't in Blender's vocabulary). |
I had 3 terms of AutoCad in 1985, and am not totally reteaching myself how to use 3D CAD. I have looked at Blender, and I suppose I really should spend some more time looking at it. I always do prefer to use Open Source solutions as much as possible, but I caved in and am purchasing this 3D CAD software I am using now.
| "trevarthan" wrote: | | I've got some Basic Electronics Theory under my belt and a few escapades with 555 timers and the like, but ultimately I'm a software guy. And I intend to become a 900 lb software gorilla on this one. |
I am majorly a Digital Guy when it comes to electronics. I want to do analog too, but I need more time for that stuff to sink in than for digital. Semiconductor theory killed my 4.0 GPA in 1985 during my 5th term in technical school. I dropped to a 3.51.
_________________
No, Mr. Jobs, the BiPod is a ROBOT. It does not play music OR interface with iTunes.
The Dynaplex Network - Robotics, Open Source, Linux, and Technology Forums |
|
| Back to top |
|
|
ginge
Site Admin
Joined: 14 Jan 2006
Posts: 1029
Location: Manchester, UK
|
| Posted: Tue Oct 17, 2006 1:31 pm Post subject: |
|
|
Welcome!
It's always good to have Linux people around, it makes me feel a little less intimidated because of the Windows guys 
| Quote: | | My intended hardware platform will be Gumstix because it runs Linux. |
Good call. This is my preferred platform.
| Quote: | | the unofficial word of a gumstix rep that they will be releasing a new board in the next 6 months or so with USB host support. |
Interesting scoop. I will be purchasing one of these.
| Quote: | QUESTIONS
=============================
1.) ginge, do you intend to release that linux code as GPL? |
For the most part, yes. I have released some fairly basic code to interact with the Gumstix as GPL. This library will soon be upgraded with lots more features, it will stay as GPL. I have some IK libraries that I have written, but these will be LGPL, as a lot of time has gone into them.
I have the old API source up on my site you can download.
| Quote: | | 2.) OpenServo uses I2C. So what do I need to connect an OpenServo I2C bus to my Intel I2C header on my motherboard? Will that work? If not, what do you folks recommend? |
I tried this, and it sucks. It doesn't run at anything like a reasonable speed (although your board might differ). It's easier to bit bang the I2C from a parallel port, or whip up some pic basic code for the job.
| Quote: | | 3.) Also, I need to purchase at least one servo to get started. I'm eyeing the Futaba S3305:... |
It should be fine. The servos are all very similar. You can't expect any problems.
| Quote: | | 4.) Do I really need to buy a programmer? Or can I buy pre-made, pre-flashed boards from one of you folks |
check out what Jay has to offer. Shortly he will b selling fully assembled boards. http://openservo.com/Forums/viewtopic.php?t=188
You shouldn't need a programmer for this, as you can update it over I2C... although a basic programmer consists of just 4 resistors plugged into the parallel port.
Barry
_________________
http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/ |
|
| Back to top |
|
|
trevarthan
Joined: 17 Oct 2006
Posts: 48
|
| Posted: Tue Oct 17, 2006 3:35 pm Post subject: |
|
|
| Quote: | | I tried this, and it sucks. It doesn't run at anything like a reasonable speed (although your board might differ). It's easier to bit bang the I2C from a parallel port, or whip up some pic basic code for the job. |
So.... did you try it with the 400mhz i2c on the gumstix? And it was still too slow? I was actually just about to ask if the 400mhz i2c bus on the gumstix would be compatible with the (slower?) i2c protocol that OpenServo uses. I guess the answer is, ""yes, but it's still too slow?"" I don't really understand how that could be, but I'll take your word for it. I suppose it's a driver issue?
I need a cheap, fairly quick way to get i2c into my computer. Can you recommend a parallel port adapter? Or would a microcontroller circuit be cheaper? On the linux end, would the microcontroller solution look the same as the parallel port adapter from the perspective of the GPL code you've written? Or would I have to change things if I go with a parallel port adapter?
I want to get something running quickly at this point, then I'll take the time to branch out into other areas once I know what to expect. |
|
| Back to top |
|
|
ginge
Site Admin
Joined: 14 Jan 2006
Posts: 1029
Location: Manchester, UK
|
| Posted: Tue Oct 17, 2006 4:00 pm Post subject: |
|
|
Yeah, I currently power my rig using a gumstix. was referring to motherboard I2C. I had one on an AMD motherboard, and it was limited to 100khz, and would flake out constantly. It's definately not a good dv platform.
Gumstix allows 100khz and 400khz, although the 400khz option requires a kernel patch in the buildroot. I havn't tested the 400khz mode too extensively, as you noted, the OpenServo is fairly limited in speed. I reliably get 80-90khz throughput on an OpenServo without instabilities, but that could go faster, i'm sure.
With regard to your I2C interface... either use a gumstix, in which case the code I have works without modification (using /dev/i2c), or alternatively use a bit bang interface for parallel io, there is a kernel driver (i2c-parport) that will let you connect the /dev/i2c interface to your hardware. There is a sample parallel interface hidden in some kernel documentation that works well for development.
http://archives.andrew.net.au/lm-sensors/msg27432.html
Basically my libs work with /dev/* interfaces, whichever you choose
Unfortunately my libs are not compatible with MCU, as this would take a large amount of additional code.
You can use a PIC for basic embedded development, or maybe something like the Basic stamp. These are rapid development tools, but not cheap, or easy. It all depends on what you are trying to achieve.
Barry
_________________
http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/ |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
