[Konvas] off-topic -- motorized heads

[Sean McVeigh]

Wow!  Will it run Linux too? =)

I can understand where you're coming from with process control, as that 
sort of work is typically multiple actuators and sensors driven from a 
central point... In that case, ethernet, CAN, or RS-422 or something 
makes sense.  I should mention that all he asked for was a head that he 
could roughly dial in to do fixed-speed pans...  but how boring is a 
computerized head that only has a single knob for an interface :)

This is no more complicated than any sort of minor robotics work I've 
done in the past.  My microcontrollers of choice have generally been the 
Cygnal/SiLabs C8051Fxxx family.  They run around 25MIPS, have anywhere 
from 16 to 64 pins of GPIO, built in SPI, I2C, ADCs, DACs, etc.  Great 
little toys.  And usually $5-$10 a piece :)  Used them in anything from 
wine cellars, to arcade machine controls, to weather stations, to SMPTE 
timecode devices (and slates).
I'm doing my own board up -- simple FET-driven stepper motor interface, 
probably a tiny display and input knob or keypad, and perhaps a joystick 
plug... trying to decide whether I need to incorporate an optical 
encoder on the drive shaft for feedback or not.  Depends on whether or 
not repeatability accuracy is a factory :)

Will definitely take some photos this time around, as I'm sure it will 
be of interest to someone.

Cheers,
Sean

Peter Haas wrote:
>
> On Dec 11, 2008, at 12:16 PM, H. W. Stone wrote:
>
>> The people I have talked to recommend running it via a laptop-- not 
>> directly.  They also recommend MAC over PC, and that you use Firewire 
>> to connect it instead of USB2, but USB2 "will normally" work fairly 
>> well.  That apparently keeps the problems to a minimum, and allows 
>> you to upgrade joysticks, controllers, and store moves to use in 
>> different locations weeks later, too.
>>
>
> Hmmm.
>
> Coming from a process-control background (in another lifetime), I 
> would recommend Ethernet and a Java-based application, driving a 
> Rabbit one-board processor/controller.
>
> The Rabbit has enough programmable inputs/outputs to do almost 
> anything, and it has a browser-based interface, and Ethernet, built-in.
>
> (If your motion-control applications must be super-secure ... LOL ... 
> you can opt for SSL).
>
>
>
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