Project - Dynamixel AX12 motors

Hi Justin,

It’s just a thread.sleep(1000), I forget to remove …

;-(

nice one, i am very tempted to get some of them… :slight_smile:

Justin,

How are you using the smileys ??

: D : ) ; ) etc without the spaces :wink:

Also these look very interesting and i think the protocol might be easier as they use standard baud rates

http://robosavvy.com/store/product_info.php/products_id/1807

:smiley: thank you :slight_smile:

The beauty of AX-12 it’s everything could be setup, including the baud rate from 7.874 bps up to 2.000.000 bps. The default value is 1.000.000.

It is for me, by far the best quality/price servo as of today. you have no obligation to go with the default value bps.

I think i might have to get one of each to compare then start a project…

Hello GUS

You wrote:

U0FDR.Write((8 << 4) | 1); // fix the fractional divider register

Would you please answer me the following questions:

1.)
Where does the value (8 << 4) | 1 com from ?
How is it calculated ?

2.)
How do I calculate this value for other baud rates like for example 200 or 800 kBaud ?

3.)
Why do I have to fix this register manually at all ?
Why does the framework not already do this calculation for ALL baud rates that are passed to new SerialPort(…) ?

4.)
Where do I find detailed documentation about the processor registers of the LPC2388 ?

This is from years ago. I am not going to be able to remember anything. But looking the processor user manual will reveal everything you need. You can find the documentation at www.nxp.com

I found a document at NXP.com that explains the formula to calculate the baud rate.
http://www.nxp.com/documents/user_manual/UM10120.pdf
at page 96

But apart from the FDR register it requires values from DLM and a DLL register.
What values does GHI write to these registers ?
I don’t even know the clock frequency that is used as input for the divider.

So without additional information from GHI electronics this formula is useless to me.

Can you at least tell me which are the baud rates that the GHI framework assures to be calculated in the acceptable range of +/- 2% from the desired value ?

I suppose these are:
50
75
100
150
300
600
1200
1800
2000
2400
3600
4800
7200
9600
19200
38400
56000
57600
112000
115200
224000
448000

Is this correct ?
Are there more ?
Are they less ?
Where do I find this information ?

I suggest you open the COM port managed code and then reset all baud rate registers to whatever you like. I remember nxp having a calculator somewhere