Snoopy has a BeagleBoard backpack!
Posted 2 Weeks Ago at 02:00 AM by kamondelious
Last night I was stoked to get finished, so I was up a little late, but the reward was worth it. 
Fastened the corners with my handy packing tape. Same as the base, one strip 32cm long to wrap around the entire thing. I learned from my difficulties with the base and cut the strip so it was about 3/4 the width. There was less to wrap around to the inside and it was much easier to work with. the result was a much prettier looking lid.
Then cut holes in the lid lining them up with the base. I need new blades for my xacto knife. This was far more tedious than it needed to be. Wish I'd brought either my drill or dremel when I moved to Hong Kong. Might have to get new ones for the next little project like this. I considered using my soldering iron to burn the openings, but didn't want to deal with the smell or the clean up. I did mess up and over sliced up from the DVI port's top right corner. Nearly to the top of the lid! The plus side is it's not very noticeable.
The end result came out almost as good as I hoped. I was aiming to be able to see into it better, but my mildly botched tape job on the base took away from that splendor. Oh well, I'm still happy with it. With the lid finished and on, the whole container is quite sturdy. The fears of a smashed BeagleBoard due to a backwards fall are gone.
Now that all the pieces are done, was time to put it all together and fire it up!
Bolted the base on. I had to consider the orientation of the base carefully as there is going to be an SD card sticking out. I'd hate to have a catastrophic failure do to Snoopy accidentally smashing himself in the SD card. Luckily for me, I did that pondering over the weekend while I was fresh, so I only needed to recall which way was up.
It was late. I just finished tightening the last nut to hold the BeagleBoard in place when I realized I forgot to attach the serial line. Opps! Couple minutes more and we were assembled and styling.
Last thing was to plug Snoopy in and see the pretty lights.
Looking good Snoopy!
Now I need to ensure I get Snoopy setup for wireless connectivity to my PC and setup an NFS mount to there. I'm going to start off with bluetooth as I have a few dongles already, but my initial tests with my PC hasn't been great. My laptop worked ok which was odd. Not sure what I boffed there. Worst case, I'll find a Wifi USB stick that works well with the BeagleBoard and get one.
Then, go back over my code for the CM5 and ensure that my servo command relay setup is still looking good. Then get to work writing Snoopy's servo control system.
I'm planning on an SQLite DB on the backend, that works 2 fold. In memory and on disk. Short term and long term memory.
I might be a little too ambitious with my 256MB ram and 500MHz processing power, but what the heck. I should be able to make Snoopy just focus on the now and have my PC be the "subconsciousness". Something to that effect.
I'd love to hear other's opinions/exploits on anything like this.
Cheers for now!
Fastened the corners with my handy packing tape. Same as the base, one strip 32cm long to wrap around the entire thing. I learned from my difficulties with the base and cut the strip so it was about 3/4 the width. There was less to wrap around to the inside and it was much easier to work with. the result was a much prettier looking lid.
Then cut holes in the lid lining them up with the base. I need new blades for my xacto knife. This was far more tedious than it needed to be. Wish I'd brought either my drill or dremel when I moved to Hong Kong. Might have to get new ones for the next little project like this. I considered using my soldering iron to burn the openings, but didn't want to deal with the smell or the clean up. I did mess up and over sliced up from the DVI port's top right corner. Nearly to the top of the lid! The plus side is it's not very noticeable.
The end result came out almost as good as I hoped. I was aiming to be able to see into it better, but my mildly botched tape job on the base took away from that splendor. Oh well, I'm still happy with it. With the lid finished and on, the whole container is quite sturdy. The fears of a smashed BeagleBoard due to a backwards fall are gone.
Now that all the pieces are done, was time to put it all together and fire it up!
Bolted the base on. I had to consider the orientation of the base carefully as there is going to be an SD card sticking out. I'd hate to have a catastrophic failure do to Snoopy accidentally smashing himself in the SD card. Luckily for me, I did that pondering over the weekend while I was fresh, so I only needed to recall which way was up.
It was late. I just finished tightening the last nut to hold the BeagleBoard in place when I realized I forgot to attach the serial line. Opps! Couple minutes more and we were assembled and styling.
Last thing was to plug Snoopy in and see the pretty lights.
Looking good Snoopy!
Now I need to ensure I get Snoopy setup for wireless connectivity to my PC and setup an NFS mount to there. I'm going to start off with bluetooth as I have a few dongles already, but my initial tests with my PC hasn't been great. My laptop worked ok which was odd. Not sure what I boffed there. Worst case, I'll find a Wifi USB stick that works well with the BeagleBoard and get one.
Then, go back over my code for the CM5 and ensure that my servo command relay setup is still looking good. Then get to work writing Snoopy's servo control system.
I'm planning on an SQLite DB on the backend, that works 2 fold. In memory and on disk. Short term and long term memory.
I might be a little too ambitious with my 256MB ram and 500MHz processing power, but what the heck. I should be able to make Snoopy just focus on the now and have my PC be the "subconsciousness". Something to that effect.
I'd love to hear other's opinions/exploits on anything like this.
Cheers for now!
Tags: beagleboard, bioloid, snoopy
Total Comments 8
Comments
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Wow! Great project!
I'd love to see some overall shots of your robot, is it going to be a biped/quad hybrid?Posted 2 Weeks Ago at 10:51 AM by Tyberius 
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Hey Thanks!
I have pics in my Bioloid album.
http://forums.trossenrobotics.com/album.php?albumid=32
I should probably get some more up there.
Snoopy is biped, though I'm suspecting he's going to crawl before he walks. Does that count as hybrid?
Posted 2 Weeks Ago at 11:44 AM by kamondelious
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Man that is a lot of AX-12s... I have a sneaking suspicion you're going to run into some payload issues, especially with that wide of a hip stance. As a point of reference, Jon Hylands found that even the stock bioloid humanoid can only carry about 500g of payload before it buckled and was unable to walk.
Posted 2 Weeks Ago at 12:48 PM by Tyberius
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Yeah, the payload has been a bit of a concern and part of the motivation behind lowering the centre of gravity by moving the CM5/Battery to the hips. Part of why I reworked the legs had to do with they seemingly inefficient stock configuration as well as poor range of motion.
Typically a low wide stance is more stable. This is seen in most sports, sumo wrestling being a perfect example, but again raises the issue of payload. I am definitely pushing the 500g mark with the additions I've made.
Hopefully my configuration is a lot more efficient and helps with this and/or I'll have to work some serious magic with weight distribution to achieve walking. I've definitely been working to minimize servo stress and give Snoopy a natural balance under his own weight.
With any luck I will get some time shortly to play about and see. I only changed my hip configuration a few weeks ago and haven't had time to try out the new one. I was having balance issues before that which was attributed to a high centre of gravity.
Then again, maybe I'll discover it just looks cool but needs to be completely reworked. It's fun if it works and it's fun if it doesn't. At least I can count on that!
Thanks for the input Tyberius.Posted 2 Weeks Ago at 06:02 PM by kamondelious
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Oh, just thought of this.
My saving grace may end up being a different battery. Like the Li-Po battery pack in the Bioloid Premium kit. The higher voltage would give better payload capacity. The AX-12's, according to Robotis have a lot more torque at 9.6V than 7V. Which I believe is all I get with the stock battery.
Perhaps I ditch the CM5 and stock battery altogether and use a USB2Dynamixel and a Li-Po battery. Probably a better solution regardless.Posted 2 Weeks Ago at 06:20 PM by kamondelious
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Hey Tyberius,
I think I initially missed the point of your wide stance comment. Sorry for that.
I was thinking in terms of a standing stance, it will be more stable, but when it comes to walking it will need to be carefully considered. The weight transfer from foot to foot will have to compensate for the wide hips which could be problematic. I'm betting that's more of what you were suggesting.
Maybe I should refer to Snoopy as "she" instead of "he" as there will probably be some sexy bum wiggle in the gait.
Thanks again!Posted 2 Weeks Ago at 09:56 PM by kamondelious
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A 3S LiPo will provide you with around 12v (stock battery is 9.6v) which is a decent increase. I'd say it's a definite must for any humanoid.
I experimented with a wide hip stance with my Hagetaka project, in both Bioloid and RX-64 formats and ultimately ditched the design for a more traditional one. The problem is, with any substantial payload there is a decent amount of 'slop' in the geartrain on these servos, and it was enough that it kept the legs from lifting well enough to walk. Even at very tight PID settings you get either get jittery and/or simply max out their ability to move into correct position. It's the Hip and Ankle 'roll' servos you have to look out for.
Not trying to discourage you from trying new designs, just sharing my own personal experience with custom bipeds, wider hip stances, and high payloads using the bioloid/rx series servos.Posted 2 Weeks Ago at 10:25 PM by Tyberius
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Sweet I'll look into that battery.
Yeah, the hip and ankle roll was what I figured would be the "weakest link". Makes sense.
hehe, if I was worried about negative comments or criticism and such I'd never have started blogging my endeavors here. I asked specifically for input from anyone with similar experiences and such. I feel that's exactly what you've done and your input is very much appreciated.
I "fear" that you're right, but it's not a huge loss if it doesn't work. Just means I get to switch up my design again. I've got a fair bit of work to do before I'd get to the walking part anyway, but the foresight is good.
I should be able to do some basic tests to see how it'll hold up though. I'll have to try and make time to do that.Posted 2 Weeks Ago at 02:15 AM by kamondelious
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