RoboSavvy Forum

problem with an AX-12+

2007-11-25T03:55:43+01:00

Thank you very much for your help, i'm going to try it!

Statistics: Posted by elvisss — Sun Nov 25, 2007 3:55 am

problem with an AX-12+

2007-11-23T14:38:30+01:00

It would be possible, but you would have to be very careful to avoid writing to the bus while a device was responding.

If you wanted to ensure that no device responded, you could just send SYNC_WRITE commands.

Here are byte strings for three different SYNC_WRITE commands, which set the servo with ID=1 to position 0, 511, and 1023 respectively:

Code:: 0xFF 0xFF 0xFE 0x09 0x83 0x1E 0x04 0x01 0x00 0x00 0x52 0xFF 0xFF 0xFE 0x09 0x83 0x1E 0x04 0x01 0xFF 0x01 0x52 0xFF 0xFF 0xFE 0x09 0x83 0x1E 0x04 0x01 0xFF 0x03 0x50

- Jon

Statistics: Posted by JonHylands — Fri Nov 23, 2007 2:38 pm

problem with an AX-12+

2007-11-23T08:11:40+01:00

yes, I know the protocol, since I triedd to send data to the AX12 with an Atmega...but If I don't care about the data sent by the motor (I know, it's stupid...), could it be possible?

Statistics: Posted by elvisss — Fri Nov 23, 2007 8:11 am

problem with an AX-12+

2007-11-23T05:08:51+01:00

No, you can't. You can talk to it from a micro-controller, with some supporting hardware (or with none if you're using an ATmegaXXX), or you can use an interface board like I sell.

The problem is the serial bus is a one-wire bus - both Rx and Tx are on the same line.

- Jon

Statistics: Posted by JonHylands — Fri Nov 23, 2007 5:08 am

problem with an AX-12+

2007-11-23T04:36:53+01:00

Thank you very much for your help!
I have an other question...is it possible to send data to an AX12 directly from a serial bus if the speed of the servomotor is, for instance, 9600 bps?...
I know this is not very fast, but i would like to make tests with only one motor, to know if i should buy more...

Statistics: Posted by elvisss — Fri Nov 23, 2007 4:36 am

problem with an AX-12+

2007-11-19T15:06:28+01:00

Yes, my board gives you direct access to the bus. You can open the serial connection at any baud rate you like, and send out a series of pings to each allowable ID to see if you get a response (that's what I do).

It also works fine in Linux - the drivers for the FT232 were included back in around 2.4, so anything after that should be fine.

- Jon

Statistics: Posted by JonHylands — Mon Nov 19, 2007 3:06 pm

problem with an AX-12+

2007-11-19T02:15:41+01:00

your board seems very interesting!
But what about the software?...I run under linux...
I fact, I was thinking to buy a CM5 because it has a scan mode (only for this reason...) because I am not sure of the adresse and of the speed of my AX12...
is it possible to do so with your board?

Statistics: Posted by elvisss — Mon Nov 19, 2007 2:15 am

problem with an AX-12+

2007-11-19T01:27:54+01:00

I sell a board that allows a PC to talk to the Bioloid bus directly over USB.

http://www.huvrobotics.com

I also have some code on my site that works as a bus device on an ATmega. See http://www.bioloid.info, under User Projects on the 6-axis IMU page.

- Jon

Statistics: Posted by JonHylands — Mon Nov 19, 2007 1:27 am

problem with an AX-12+

2007-11-17T13:43:52+01:00

Thank you for the tip!
But now, I understand nothing ...
I wrote several codes, and none is ok...I have now way to check the speed of the second USART, the one at 1 Mbps...
And when I try to use both USART, I have strange results...
I connected Rx and Tx pins of the second USART , and I try to desactivate the TX pin in order to be able to recieve data...but it doesn't work...
I never programmed Atmega before...with only one USART, it's ok, but with two, it's too difficult...
Does anybody has a good code for an Atmega 324?
I begin to think about buying an CM5 or USB2Dynamixel...

Statistics: Posted by elvisss — Sat Nov 17, 2007 1:43 pm

problem with an AX-12+

2007-11-17T12:30:27+01:00

Yes, you can use 1 Mbps from an 8 MHz ATmega. I do it all the time.

AX-12 has nothing to do with RS-485.

How do you have the bus connected to your ATmega?

- Jon

Statistics: Posted by JonHylands — Sat Nov 17, 2007 12:30 pm

problem with an AX-12+

2007-11-17T11:28:09+01:00

Hello,

I tried during 5 or 6 hours, but no results...
I would like to know if it is possible to use the 1 mbps at 8 MHz...maybe the problem comes from this point...

I also wanted to know something about AX-12 and RS485...
because I have a board on which I will plug my Atmega, and the board has a RS485 port...

But I am a newbie, so i am not sure if it is possible to send data from the board directly...

Thanks for the previous answers!!

Statistics: Posted by elvisss — Sat Nov 17, 2007 11:28 am

problem with an AX-12+

2007-11-17T05:24:46+01:00

I think the default baud might be 34 (0x22) ? - thats what it is for the DX-117. Also, the red light is standard.

Statistics: Posted by hivemind — Sat Nov 17, 2007 5:24 am

problem with an AX-12+

2007-11-17T02:58:55+01:00

Thank you,
I'm going to check it...
and what about the red led?...is it a normal color, or does it mean there is a problem?
It only blinks once, then stay switched off...

Statistics: Posted by elvisss — Sat Nov 17, 2007 2:58 am

problem with an AX-12+

2007-11-16T17:44:01+01:00

If you look through the manual these different speed setting. I only have DX-117 to go by, but most of them came with the same setting but one had a different speed and ID2 so took me some time to figure out why it wasn't working.

Bren

Statistics: Posted by Robo1 — Fri Nov 16, 2007 5:44 pm

problem with an AX-12+

2007-11-16T14:24:43+01:00

Thank you for your help, I'm going to try it...
but I thought the default speed is 1mbps...or is it an other thing?...

Statistics: Posted by elvisss — Fri Nov 16, 2007 2:24 pm