BeagleBoard C4 and KHR-3HV

[Teng]

Hi! Been thinking for ages of venturing into humanoid robot. In the short term, plan to get a humanoid robot to move about autonomously(sense, balance and navigate).

Has anyone tried any of the following robot controllers on KHR-3HV(with RCB-4HV)?

[1] Pololu SV-328
[2] Phidget SBC
[3] Gumstix Verdex Pro with Robostix
[4] BeagleBoard

Also, can someone please enlightened me on the necessary set-up(power supplies, meters, scopes, tools, etc.) for a fulfilling time? Thanks a lot!

[limor]

We are working on a general linux interface board.
http://robosavvy.com/forum/viewtopic.php?p=27718#27718
In the meantime get the khr
And if u cant wait for the interface board to be ready then develop something of your own and get gumstix or embest.com

[Teng]

Hi Limor, thanks! Went a hunt for more info on Gumstix for a quite a bit after that. My only gripe about using Gumstix is with the use of ATMeg128 microcontroller for Robostix. Will that not set a severe limit on the processing capability of the robot controller? Or maybe the real processing is done at Verdex Pro so it does not really matter? Will the Robostix not become a bottleneck?

Terribly sorry if the above question appears rather out of sort. Still not really clear of how Verdex Pro and Robostix can be used to build a powerful robot controller.

[limor]

Robostix is an interface board. Similar concept to what we are trying to design. However you will have to hack something if you wantbto communicate with the khr servos. Judging by your questions maybe you should use the existing khr controller rcb4 and connect to the verdex via usb. Use the rcb4 as an executir of gaits and the verdex for strategy.
You might not even need the verdex power. Check out bifferboard. Which costs a fraction of the verdex + extention board. Send me an email maybe we can give you the bifferboard with the khr. sales@robosavvy.com

[chrisvo]

I have used the Gumstix Verdex Pro with Robostix and the RCB-3 (KHR-1HV) and RCB-4 (KHR-3HV). I have software C libraries already developed for both RCB-3 and RCB-4 if you would like. I have posted the RCB-4 library here:
http://bitbucket.org/vo/libkondo4

I'm currently also using the IGEPv2 (a BeagleBoard clone) with ICS protocol directly to communicate with the servos.

Tips:
1. I had no problems using the UARTs on the Gumstix to communicate with the RCB-3 but I had some issues using the Robostix UARTs; the timing appears slightly off - the correct data is being sent but the RCB-3 appears rather sensitive. The RCB-4 is a little more robust though, you may have fewer problems.
2. The RCB-4 COM port uses inverted (idle low) UART with +5v logic, 8E1.
3. If you want to use ICS 3.0 protocol directly, the servos use half-duplex circuit with +5V logic, similar to Robotis AX series servos. It's 8E1 as well.

Let me know I can send schematics for the circuits. I have three different board designs to communicate with RCB-4 and Kondo ICS 3.0/3.5 which work so far, but I haven't openly published them yet because I'm still testing. They are:
1. A USB device for direct ICS communication. It's similar to the ICS adapter sold by Kondo except it is a little more designed to let you communicate with multiple servos at once.
2. UART-to-RCB-4 adapter (rather trivial)
3. A USB device that has a socket for the FT4232H mini-module and breaks out two serial servo banks, the rest of the pins broken out into pin headers.

I am considering redesigning #1 to use the FT2232H chip, but only if there seems to be a need for it...

[limor]

Hi chrisvo,
it would be great if you can share your designs as we are in the process of designing a new interface board that will work with ICS3 and Robotis, Robobuidler etc. http://robosavvy.com/forum/viewtopic.php?p=27718

thanks

Limor

[Teng]

Great! It is really much more reassuring to begin with a platform that have already been used on the KHR platform! Let me begin to get my hands dirty and my pocket emptier! Let's see who is the lucky merchant

Be back with more concise questions! May all of you have a great time cracking your head to get your humanoid to do wondrous stuff! Thanks

[chrisvo]

At first, I highly recommend trying to use the RCB-4HV that is included with the 3HV. It is quite powerful already, with the Heart2Heart programming interface. You can communicate to it from your micro-controller very easily using UART; even faster if you have high-speed UART.

If you want to gain even more control, the RCB-4HV still has commands that allow you to forward ICS serial packets directly through it; the latency is good enough for feedback control even with the RCB in the middle.