Zig110 potential

[haratron]

1. What is the zig110's range?
2. Can I read/set the individual servo positions wirelessly via the zigbee?

[Fritzoid]

1. According to wikipedia, the zigbee pro can communicate over distances of up to 1500 meters, . It is designed to operate in a noisy environment with lots of other wireless devices, like an industrial assembly line. This is precicely the environment one might expect at a typical robotic soccer competition!

2. Not directly!. The zigbee protocol in the Bioloid firmware only allows for the transfer of two bytes at a time. Furthermore, the transmitted integer is only available to RoboPlus Task programs running on the CM-510 in play mode. So, you have to write custom routines in RoboPlus to read the zigbee (Remocon) and to act on the transmitted data.

[haratron]

Thanks for the reply Fritzoid.

1. I was referring to the practically tested range of those particular zigbee modules contained in the zig110 package. Anyone has measured it?

2. I don't quite understand. This is vital to me. Is there an alternative? I want to be able to read/set the positions of all servos at any moment without much delay. Can I possibly flash the bioloid zigbee firmware or something?

Could I perhaps do this with libbioloid? I haven't got an answer to whether this is for the 510 too though.

[Fritzoid]

I want to be able to read/set the positions of all servos at any moment without much delay

Ah yes, the Bioloid programmer's white whale!

You are not alone on this quest and there are many obstacles to be overcome.

Firstly, the relatively slow speed and high latency times that the zigbee offers will be a far bigger impediment to you than the distance limit. You'll probably want to go with Bluetooth instead.

Secondly, the CM-510 firmware only does 56Kb over the wireless link so you'll need to modify or replace the controller firmware as well. Or you could use a "piggy-back" processor like a gumstix or roboboard to bridge the gap.

Then there's the speed and control issues on the dynamixel bus. These requirements limit throughput to and from the servos to about four reads per millisecond (at best). That makes closed-loop control of a robot with 20 or more servos hard to achieve.

But it will definitely be cool once you get it workin'.

[haratron]

I would expect this to be so essential that I cannot belive it hasn't been done already. That is essentially an autonomous robot, what Robotis wants from what I know.

Isn't there a howto/tutorial on how to do this?

As for Bluetooth, I've read on this forum that a lot of people are against it and prefer zigbee over it. :/

[haratron]

Can I use the bifferos (http://robosavvy.com/forum/viewtopic.php?t=4361 ) to do that? But since I'm a newbie to robotics, I don't know how to do this..

[Fritzoid]

haratron,

Bifferos looks like a good candidate, particularly if you are familiar with the Linux operating environment.

But before you go too far down that path maybe you should get a little more familiar with how your Bioloid works. For example, have you talked to your robot in terminal mode yet?

[haratron]

Thanks again for your help Fritzoid.

I'm comfortable with Linux, yes.
Actually, I haven't bought my Bioloid Prenium yet, the only thing that is stalling me is the wireless control issue. If it's not wireless it's not autonomous to me.
I want to embed a wifi camera on it and pass the images to the PC, process them with OpenCV and then set the bioloid's servo positions via zigbee.

What do you mean by 'terminal mode'?
Do you mean reading the servo positions via USB2Dynamixel?

I searched the whole forum, I haven't found anyone that has done it (wireless communication) and provides adequate information for others to do it. Only some discussions about Bifferos and Gumstix made by Limor primarily.
Additionally, I still don't know if libbioloid supports CM510.

I don't want to get the robot and have it wired.

[Fraser]

Hi Haratron,

I'm hoping to achieve 250kbps over zig pair by changing to 8MHz crystals and changing the zig clock divider using a terminal. My chinese crystals arrived today will keep you posted with result when I get time to try it.

I've also been playing with custom firmware for AX12 and CM510 that allows control of 18 servos at a rate of 100Hz over a 250kbps link.

At the moment the servo control loop is closed by the remote PC. I am working on adding velocity and position commands so that the loop can be closed in the servo as well. When finished it should make humanoid control over zig viable. The current firmware version can be downloaded here:

http://www.ledset.com/bioloid/axons/

A quote from another post I made about zig:

This evening I played with the bioloid premium zig module pair (Zig100 and Zig110).

Some notes that others might find interesting:

As per robotis instructions you can enter the config mode on the Zig100 by plugging it into a zig2serial adapter and sending ! characters as you press the reset button on the zig2serial.

With the Zig110 you can do the same (robotis doesn't document this):

I rigged up jumper cables (zig110 to zig2serial) for RXD,TXD,VCC,GND and sent ! characters.

I pressed reset and nothing happened (because 110 has no pinout for reset)

You have to send the ! characters and then break/make the VCC line.

After entering config I changed the baud dividers to 3, this gives a baud rate of 230400.

I tried to set the CM510 to as close a baud as possible, I got damned close, lower 7 bits (ascii) seemed to flow nicely, but 8th bit gets occasionaly corrupted.

I have just ordered some SMD 8Mhz crystals and will swap them for the 7.3728MHz crystals currently on my zigs.

If all goes well then 100Hz loop freq. (with IMU data) over wireless on Win7 should be possible, faster (probably up to 200Hz) on a linux box.

Note:
to make it easier to plug jumpers in I soldered SIL sockets (actually DIL socket sawn in half) onto my zig2serial. This also gives a much more solid seating for the zig100.

[bohan]

hey.The practical range for zigbee module 110 is around 25 meters.

[MOHIT JINDAL]

Hi,
I connected Zigbee to cm510 and to Rc100. Green led On and all buttons are working but 5 and 6 are not working. Any help ?

Is there any way to control Bioloid premium with Xbox 360 controller or Ps3 remote ?
Thanks.

[Fritzoid]

Mohit wrote:

Green led On and all buttons are working but 5 and 6 are not working

Gee, were they working before you put the zigbee unit in?

[MOHIT JINDAL]

Thanks. You always help Fritzoid.
No the 5 and 6 not worked before.
Some guy on this forum said the 5 and 6 are reserved for Zigbee but they are not working.
Can they work after i tre Zigbee Sdk ?
Please answer my 2nd question also about Xbox controller.
Thanks again.