HeartToHeart 4 version 1.1.0 English Patch (OLD)

[ks_khr3]

Some off-topic fun ... check this out for the NXT camera responsiveness.

http://video.aol.com/video-detail/lego- ... 3163493354

[Ausrobo]

Hey Chris and ks,

I have been watching this one with interest.
Do you have the circuit diagram to interface the RCB 4 to TTL for use with an uart?

Cheers,
Peter

[chrisvo]

I drew the RCB-4 RX TX and GND in the same order it appears in the pinout - the RCB-4's RX is the middle pin.

A little explanation - the RCB-4 seems to use inverted 5V logic (idle low). The standard for TTL seems to be begin transmission on falling edge (idle high), but the voltage varies. The SRV-1 controller board we have uses 3.3V logic, whereas some other boards use 5V logic. The voltage requirements called for the CD74HC04E inverter (which is tolerant of both voltage levels); no logic level shifter needed.

[Ausrobo]

Chris,

Perfect and thanks!

Peter

[ks_khr3]

Hey Peter. Thanks for chiming in. Glad to know there are others out there still interested in this platform. How is it going for you?

[Ausrobo]

Chris,

Thanks. Yes still working with Kondo and H2H. Like ks it is definitely a love hate relationship! I am working on getting an Axon microcontroller working with the RCB 4 and have a CMU Cam that I am adding to the mix. The problem is the form factor of the 3HV, it really does not work. So at this stage I have moved to the workshop to build an alternate body to house a bit more.

Really I would like to move to a larger model using the 6000 servos, but that really is a way off!

Thanks again for your support of this discussion site. I am sure I would have given up without your help.

Peter

[chrisvo]

I'm right now trying to figure out how to take the KHR-3HV, and fit in the torso:
1. Two extra servos in the leg (for rotation along
2. Li-ion or li-poly battery
3. Two 500 MHz blackfin (SRV-1) processors
4. RoBoard RB-110 (1000 MHz x86)

This is the current torso design I've got, which is extremely simple and would mostly work for fitting all 4 things in it:
http://www.flickr.com/photos/christophervo/4610291401/

One big concern is keeping the body light enough so the servos don't wear out. I haven't really found a good solution yet...

[ks_khr3]

Wow. Would you still keep the RCB-4 in the mix in that configuration? That's quite some processing power you would have in there. Taller torso also brings with it a higher CG which could be a problem right? How about keeping the current torso shape but using the mid section where the battery goes for some extra cards and then make a simple clip for the battery in the chest. Could have a light polycarbonate cover over it for aesthetics if you care about that. Just an idea.

I am struggling with the KCB-1 fitout. I placed it on the right panel as shown on the instructions but there is no place offered for the radio receiver + the KRI-3 interface thingy. I will build a simple double-decker platform for the left panel and try to install them over the gyro + accelerometer. Should work out but the cabling is turning into a mess.

Taking some time off since I'll be away on business trip and then holidays but should be good opportunity to read the SDK docs over & over and try to make sense of it all. Keep well.

[chrisvo]

Wow. Would you still keep the RCB-4 in the mix in that configuration?

No, I think we would try to control the robot entirely from the RoBoard. No idea yet whether we can...

Taller torso also brings with it a higher CG which could be a problem right?

It might be possible to use this:
http://kopropo.co.jp/cgi-bin/KO_Shop/sh ... Cbr%20/%3E

If so the servos could be mounted like this:
http://imgur.com/6nyMC

Which would make for a big butt but it would have the extra degree of freedom without being taller.... Maybe.

How about keeping the current torso shape but using the mid section where the battery goes for some extra cards and then make a simple clip for the battery in the chest. Could have a light polycarbonate cover over it for aesthetics if you care about that. Just an idea.

Good idea, actually that is very similar to how the KHR-1HV is set up. However actually it looks like the current torso design is big enough to accommodate all of these things... I hope...

I am struggling with the KCB-1 fitout.

Yeah there's not much space in there...

[ks_khr3]

It might be possible to use this:
http://kopropo.co.jp/cgi-bin/KO_Shop/sh ... Cbr%20/%3E

If so the servos could be mounted like this:
http://imgur.com/6nyMC

Which would make for a big butt but it would have the extra degree of freedom without being taller.... Maybe.
..

Don't get it. If you want to be able to do splits why not use the Kondo retrofit kit for this purpose? http://www.vstone.co.jp/robotshop/index ... ts_id=1702



Am I missing the point?

[chrisvo]

Well, it's more important to us to get the leg rotation. Doing the splits is not really a big deal for us, in fact I don't really care about it at all...

[ks_khr3]

So leg rotation as in what the extra 5 DOF kit gives you? As in here :

[chrisvo]

Yes, exactly. Except that we've found that the waist assembly is a bit too fragile for our purposes. It tore apart a few times on our robot. That's why on our current robot, we bolt the metal bracket directly to the frame instead of using the plastic waist assembly.

One way we have considered for achieving the rotation in the hip is to drill holes in the bottom aluminum plate and insert the servos into the torso. This is acceptable for us. However, I was looking around for other ways we could do it ...

[ks_khr3]

Understood. I agree. It is quite flimsy. How about using Carbon Fiber plates (readymade) instead of the metal for your torso parts? That could help with the weight issue some. Not sure how much but it might be worth doing a rough back of the napkin calculation to see if its worth doing. Good luck!

It might be possible to use this:
http://kopropo.co.jp/cgi-bin/KO_Shop/sh ... Cbr%20/%3E

Let me know if you wish to use this part but the shop doesn't ship overseas. I would be happy to receive in Tokyo & forward to you. Least I can do to help someone as helpful as yourself.

[chrisvo]

Thanks for the offer. It is really helpful to know someone in Tokyo. We probably won't need that bracket after all, but we will want to get some metal servo horns at some point. I think RoboSavvy sells them though so we're probably covered.

Yesterday, we went ahead and prototyped a design for how to mount the servos inside the aluminum body, using all original KHR-3HV brackets and only replacing one aluminum plate with our own. The servos are oriented in a much different way, allowing us room in front and back of the servos to put battery and electronics, and rough calculation says everything will fit.

The main thing we're waiting on is figuring out how tall the robot has to be. The rules of RoboCup are strict about the ratio between height and foot size; if our feet are small, the robot can be shorter, but if our feet are big our robot must be taller.

We've looked at carbon fiber and also fiberglass for our application. We are using 6061 aluminum right now in most of the body, which is pretty durable, workable, and light at the thickness we're using, and much cheaper than carbon fiber plates. We might consider some anodizing for a more durable hard black finish.