Re: [uracoli-devel] New project: wireless DMX board

[Eric Jennings]

I'm sure Axel/Joerg can confirm, but since the Atmel radios can max out at 
2Mb/sec, I'm pretty sure the AVRs will be able to support the lower speed 
250kb/sec.

I guess the bigger question is, if the timing is meant to be very precise, you 
may need some sort of buffer to keep things straight and clean?

-Eric


On Jan 27, 2013, at 11:56 AM, Charles Goyard wrote:

> Hi list,
> 
> it's been long since I didn't use uracoli, but here's a new project !
> 
> What I want/need to do is implement a small board that can receive DMX
> data from a light controller (something like this:
> http://www.ledstagelightingfixtures.com/photo/pl576845-40_channels_2048_dmx_lighting_controller_control_240_computer_lights.jpg),
> and send it to remote nodes, that are custom made light fixtures (for
> led dimming).
> 
> DMX compatibility is at premium. This was missing from my first project
> (the juggling balls).
> 
> However DMX is precisely timed : 250kbps, with a pause of somehting like
> 92uS between frames. (see https://en.wikipedia.org/wiki/DMX512#Protocol).
> 
> I was wondering if a single AVR will be able to both receive the data
> from the serial port and build the 802.15.4 packet. Notice I won't be
> sending the full 512 bytes DMX frame, only 10 bytes (I only have 10
> remote nodes).
> 
> Maybe I'll need to have two avrs on the sender side ? One for receiving
> and parsing the DMX traffic, and the other one just to send the frames
> in the air ?
> 
> Let me know if you have some insight with this.
> 
> Thanks,
> 
> -- 
> Charles
>