Snoopy's got net
Posted 12-19-2009 at 02:13 PM by kamondelious
Updated 01-09-2010 at 09:07 AM by kamondelious (Catagorized)
Updated 01-09-2010 at 09:07 AM by kamondelious (Catagorized)
I finally managed to get my hands on a USB wireless NIC with a Linux friendly (Realtek RTL8187) chipset. Wasn't really that hard to get, maybe it's just me, but the order seemed to take forever to arrive. Worse yet, I didn't get the one I ordered. The one I had ordered was about 2/3rds the size of what I got.
The silver lining to this is that the one I did get, has the same chipset and the circuit board is the same length of the BeagleBoard. This made for an easy addition to Snoopy's backpack.
Snoopy now as wireless network access, including internet and an NFS mount to my primary computer for data storage. Best of all, I can now connect to him via SSH after simply powering him on. Now, I can using the BeagleBoard's serial connection for communication to the CM5 and get down to some serious robotic goodness.
While I was waiting on Snoopy's wifi to arrive, I was able to get parts for and begin work on making Snoopy's head. I got a USB powered speaker for audio out and a couple little USB webcams for eyes.
I was quite impressed with the sound quality from this little thing, so it was hard to resist the purchase.
The webcams weren't as small as I was originally aiming for, but I was able to work with what I got ok.
They are manual focus which will probably get annoying eventually, but the novelty hasn't worn off yet.
The webcams will do 30fps @ 640x480 with decent quality. At this point, I think it's more important that I get Snoopy seeing at all rather than fussing over some fancy auto-focus feature.
Snoopy's head is still rough, but definitely felt good to have him with one.
I still need to work out exactly how I'm mounting his "voice box". I don't want to wreck that pretty face, but there needs to be holes of some manner or he'll only ever mumble. I have a black, round, metal grate thing that was part of the speaker that I'm hoping to use. It looks cool, but I'm not sure if it'll work. I'm probably going to end up with a horizontal slit for a mouth opening, seems to work ok for people, and might add to the existing "muppet" appeal he has going on now.
Looking good Snoopy! Not sure what your ears will look like, but that will come sometime after I get your hearing working. Hearing is going to require me to build a stereo microphone amplifier as the BeagleBoard doesn't have it built in. I have looked over a few schematics I've come across and it seems fairly straight forward. Time for another parts shopping spree, just in time for x-mas!
Here's a picture of Snoopy's updated backpack.
You can kind of make out how the wifi card is mounted just under the lid. The antenna is pretty long @ 19cm, but it should help with signal quality/range. I need a better picture of Snoopy with the Antenna, I know.
Cheers for now!
The silver lining to this is that the one I did get, has the same chipset and the circuit board is the same length of the BeagleBoard. This made for an easy addition to Snoopy's backpack.
Snoopy now as wireless network access, including internet and an NFS mount to my primary computer for data storage. Best of all, I can now connect to him via SSH after simply powering him on. Now, I can using the BeagleBoard's serial connection for communication to the CM5 and get down to some serious robotic goodness.
While I was waiting on Snoopy's wifi to arrive, I was able to get parts for and begin work on making Snoopy's head. I got a USB powered speaker for audio out and a couple little USB webcams for eyes.
I was quite impressed with the sound quality from this little thing, so it was hard to resist the purchase.
The webcams weren't as small as I was originally aiming for, but I was able to work with what I got ok.
They are manual focus which will probably get annoying eventually, but the novelty hasn't worn off yet.
The webcams will do 30fps @ 640x480 with decent quality. At this point, I think it's more important that I get Snoopy seeing at all rather than fussing over some fancy auto-focus feature.Snoopy's head is still rough, but definitely felt good to have him with one.
I still need to work out exactly how I'm mounting his "voice box". I don't want to wreck that pretty face, but there needs to be holes of some manner or he'll only ever mumble. I have a black, round, metal grate thing that was part of the speaker that I'm hoping to use. It looks cool, but I'm not sure if it'll work. I'm probably going to end up with a horizontal slit for a mouth opening, seems to work ok for people, and might add to the existing "muppet" appeal he has going on now.
Looking good Snoopy! Not sure what your ears will look like, but that will come sometime after I get your hearing working. Hearing is going to require me to build a stereo microphone amplifier as the BeagleBoard doesn't have it built in. I have looked over a few schematics I've come across and it seems fairly straight forward. Time for another parts shopping spree, just in time for x-mas!
Here's a picture of Snoopy's updated backpack.
You can kind of make out how the wifi card is mounted just under the lid. The antenna is pretty long @ 19cm, but it should help with signal quality/range. I need a better picture of Snoopy with the Antenna, I know.
Cheers for now!
Total Comments 8
Comments
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Wow - this is a pretty amazing undertaking. I've been down this road before (trying to add DOF and sensors/brains to an AX-12 based biped), and I wasn't able to make him walk in any reasonable fashion due to the weight. I would also be surprised if Snoopy can lift his arms for more than a few second without the shoulder servo overheating.
Definitely interesting. My quad Roz is in the process of getting a gumstix Overo onboard, with all the associated power and connection issues. I found a trendnet USB wifi adapter that is really small - http://www.huv.com/Overo-Wifi.jpg
- JonPosted 12-31-2009 at 08:31 AM by JonHylands 
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Hi Jon, Thanks for the feedback!
Were you using the stock battery pack with the CM5 when you were trying this sort of thing before? I'm definitely looking to upgrade to an 11-12V LiPo and lose the CM5 all together. That will help shed some weight and add a little more power for the servos.
Snoopy's arms are 6 servos each, which is the same as the stock leg configuration. I haven't played with him flailing his arms around too much yet, but they seem to hold ok from what I have done. Usually just having him hold his arms up/out of the way. Before I added servos and just had the 19DOF config, I was playing with some one legged balancing. Think, the karate kid, hehe. While balancing on one leg it took a couple of minutes or so before a servo would over heat. The first Bioloid video I recall seeing was one from some guy at University in Europe who'd programmed his to pour a beer in a glass. I was sold. Granted it held the can (bottle?) in both arms and bent over backwards or something to pour. I'd expect that with just an arm Snoopy should be able to pick up & hold light objects fairly well.
For walking I do anticipate difficulties, especially while I have a CM5 for hips. My plan is to try and coordinate as much of the rest of the body as I can to help displace the weight and ease the load on the most load bearing servos. Part of this, I'm thinking to point the leg in a 30 - 40 degree outstep. I think this would allow better overall stability while walking. Being able to make use of an extra servo or 2 while exerting leg force should help with better balance.
I think with carefully tuned full body coordinated balance, Snoopy should be able to walk. How much work that will take, I'm not sure, but if it was easy it would probably have been done.
Say for example, Snoopy is to take a step forward with his left foot. Weight has to transfer to his right foot in order to lift his left. This would be a matter of shifting the hips more over the right leg than the left. Then while going to lift the left leg, also lift the right arm at the shoulder and even bend the left arm at the elbow (rotating the shoulder forward a bit first). While moving the left leg forward for the step, turning at the waist and legs (and head?) at the same time. The legs turning for the step, the waist and arms adjusting just to aid in maintaining balance as needed. All this taking place inside of about 1-2 seconds. It'll be all about efficient coordination and balance.
Another trick would be to try and maintain some forward momentum while walking to save the servos having to work as hard all the time. I know there has been some interesting work going on in Universities with that in mind.
Worst case I might have to start swapping out for RX-28s or something.
Here's all the pictures I've posted of Snoopy, you should be able to make out Snoopy's leg configuration. It has a much more human range of motion than the stock configuration.
http://forums.trossenrobotics.com/album.php?albumid=32
Let me know if you'd like to see better pictures of anything and I'll snap&post some.
Those Overo boards are pretty nice. The only reason I can think that I went with the BeagleBoard over them was price. Specs are pretty similar, but the Overo has a sexier form factor.
What sorts of power and connection issues are you referring to? I'm planning to plug onto the Bioloid bus for power, hacking a servo cable with an L7805 and appropriate power connector. Is it more complicated than that or were you simply referring to the work of putting that sort of thing together? I had figured I would do that for Snoopy's USB hub first, as it's the cheapest and easiest to replace if I were to fry it. What would be a better approach?
Cheers!
AaronPosted 12-31-2009 at 03:18 PM by kamondelious
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Aaron,
Because the Overo takes almost 2 minutes to boot, I don't want to be powering it up and down all the time, so I need to be able to switch it separately. Since the overo runs off 5 volts, I don't really want to use a linear regulator like a 7805 that will waste a lot of power with heat. I'm using the Dimension Engineering switching 5 volt regulators (a pair of them) on Roz - one to power the gumstix and hub, and one for the IR range sensors.
I'm also developing a small board (1" x 2") that will allow me to plug in wall power while the battery is plugged in, and it will electronically disconnect the battery, regardless of their relative voltages, and without a voltage drop on the battery side. I'll probably start selling that board in the new year, once I get it tested.
- JonPosted 12-31-2009 at 04:07 PM by JonHylands
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Hi Jon,
Ahhh nice, I wasn't sure how bad the 7805's would heat up. It does make more sense to avoid that all together and just use a switching regulator. I think I know where I can get those here (Hong Kong) now. There was a very convenient electronics store where I was living in Markham that I miss going to. There is a whole neighborhood here that is like a cross between Active Surplus (in Toronto), Canadian Tire and a fleamarket.
That new board sounds pretty cool. Handy for sure. Uptime is good. I haven't timed Snoopy's boot time, but from power up until I can SSH in is at least a minute.
How difficult would it be to have a board that could accept a few different power sources? Say for example, 2 - 4 LiPo batteries and perhaps solar panels on top of power from a wall adapter. Do you think this would even be practical?
My thought is along the same lines as what you are already developing, so that batteries can be changed without downtime. I was also considering using smaller battery cells that could distribute the weight better and ideally (or at least novel) be able to have a 5V@~500mA solar backup for the onboard brains. I think even just a single redundant battery would be good, but this still takes us back to potential weight constraints.
I know, I need to get more proficient in electronics. I'll get there, it's so damn fun.
Cheers,
AaronPosted 12-31-2009 at 11:51 PM by kamondelious
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I just verified that Snoopy can hold a standard 6.5" pair of needle-nose pliers at arms length in front of him for over 2 minutes. I had started testing without holding anything, but got bored after a few minutes and started over with the pliers.
CheersPosted 01-02-2010 at 03:15 AM by kamondelious
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Wow, I'm impressed. We had issues with this with BrainBot, so we switched the shoulder servo to an RX-64. Now he can hold a full (unopened) soda can at arms length for 10-15 minutes without any trouble.
- JonPosted 01-02-2010 at 08:11 AM by JonHylands
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Did you order those cameras from dealextreme? They look just like the ones I ordered the other day. I wanted to switch over to stereo and using two PS3 eyes would just be too heavy and too big. Glad to see they that can be made even smaller and that the image quality and frame rate is good.
Posted 01-31-2010 at 01:54 AM by billyzelsnack 
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haha, yeah got them from dealextreme. Though they were my second choice. My first choice cost a little more, but became unavailable after I placed my order.
These work great, IMHO. My Linux workstation picks them up straight away and it was really easy to get them accessible from the BeagleBoard.
A cam that had a built-in mic would have been ideal, but I have rather enjoyed my endeavors building Snoopy some ears. I guess I'm overdue for a new post.Posted 01-31-2010 at 02:22 AM by kamondelious
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