OLA, Raspberry Pi and 0-10v

[Bjørn Christiansen]

Hay guys..

Is there a way to make something with OLA, so I can receive DMX, ArtNet, OSC or something that OLA can, and send it out as 3 ch 0-10v?

// Bjørn

[Peter Stuge]

OLA is software and 0-10V is not.

You need to develop some hardware to generate the signals that you want.

Once you have an idea for such hardware you can think about how it
would interface with the rest of the world.

OLA could be a nice part of that, an embedded Linux system could also
be a nice part of that. But the only reason to choose an rpi would be
that you want to avoid learning how to build an embedded Linux
yourself, and even then there are better choices. The rpi is not
particularly nice hardware.


//Peter

[Bjørn Christiansen]

Well, I know that OLA is software and the other hardware.

But there is the SPI plugin for the LED stribs..

// Bjørn

[Peter Stuge]

Bjørn Christiansen wrote:
> Well, I know that OLA is software and the other hardware.
> But there is the SPI plugin for the LED stribs..

Which doesn't help much if you need an analog 0-10V output..

You need a DAC and an output driver. I've seen a few DACs include an
opamp, which could be used for the driver, to reduce the number of
parts you need.

But you really have to start with how to build a hardware that
produces the signals that you need, and then see what way is best for
controlling from the digital world.


//Peter

[Mac Hosehead]

On 11/13/13, 12:56 PM, Peter Stuge wrote:

I could see connecting an opto-transistor to the LED PWM output on a
WS2801 and with more analog massaging get 0-10v. It's not the quick and
dirty solution it might appear to be at first, however.

-MH

[Simon Newton]

As others have said, the work is in the hardware. Once you figure that
out it's pretty easy to write an OLA client which twiddles the correct
GPIO pins.

Simon

On Wed, Nov 13, 2013 at 1:22 PM, Mac Hosehead <macho...@gmail.com> wrote:
>
> On 11/13/13, 12:56 PM, Peter Stuge wrote:
>>

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[Bjørn Christiansen]

Hay.

I know its mostly Hardware, but what about doing it as pulse width modulation (PWM) on the GPIOs?

// Bjørn

[Simon Newton]

I think there is only one PWM pin. If you could find a SPI 0-10V
interface you'd be set.


Simon

> // Bjørn

[Bjørn Christiansen]

What about this:

http://www.tbideas.com/blog/2013/02/controling-a-high-power-rgb-led-with-a-raspberry-pi/

//Bjørn

[Simon Newton]

That may work, I'll leave it to the hardware experts to comment though.

Simon

>
> //Bjørn

[Sean Sill]

Bjorn what do you want as the end result?

[Andrew Frazer]

Nice less those Ledengin ones.    I've just deployed 800 of the RGBW ones on a project. 

I've your looking for a 0-10V output, using PWM is a pretty good idea.    General idea is that you you pass a PWM signal through a low pass filter, and you'll get a DC voltage that is proportion to the PWM Duty Cycle.

You can also use a resistor string, with switches, but this will consume lots of GPIO. ( and your RPI is lacking those ). 

I'd probably go for a External DAC that worked on SPI or I2C.   Max548A, MAX5353 and MAX518 are all worth looking at.  Not that they are only going to give you 0-3v3/5V outputs, so you'll need to follow those with an opamp or some transistors to provide the appropriate level of gain to get to 0-10V

Have you got some old analogy dimmer packs that you are trying to connect?    You could probably cheat and find a DMX --> 10V converter.

[Bjørn Christiansen]

I was so lucky to get my hands on 20 Martin cyclo ip65 0-10v version.
http://www.martin.com/product/product.asp?product=cycloip65series
So I want to make 2 wireless artNet nodes, where I could skip the dmx part.

//Bjørn

[Mac Hosehead]

> //Bj�rn
>
Something to note when controlling 0-10V Fluorescent or LED
architectural fixtures is that an interface that sinks is needed. That
is to say the fixture supplies the 10 volts on the control line and the
interface pulls it down to the level required. Most interfaces are
designed as either source or sink but some can do both. If you are
designing your own, the output of an op-amp would work. Control currents
are usually less than 5ma per fixture.

-MH

[Stefan Krüger]

i think its the easiest to not skip dmx- use a finished dmx to 0-10V interface..
(for example something like http://www.shop.dmx4all.de/DMX4ALL-Products/Decoder/Analoginterfaces/DMX-0-10V-Interface.html - please check the datasheets this device can drive 10mA i don't know what the martin thing likes..)
and if i understand it right - you would have long cables with the 0-10V signal so you can reach all 10fixtures per node?!
or do you just want to control all 20fixtures with the same values? so you really only need one channel per color?
than you could build one by yourself - the easiest way i can think of is to get an arduino use the http://www.opendmx.net/index.php/Arduino_RGB_Mixer and some filter / driver to get the PWM to 0..10V
(an arduino has about 8 pwm outputs. on some of them are 16bit possible.)

sunny greetings
stefan


On Thursday, November 21, 2013 3:15:29 AM UTC+1, machosehead wrote:

On 11/20/2013 10:05 AM, Bj�rn Christiansen wrote:
> I was so lucky to get my hands on 20 Martin cyclo ip65 0-10v version.
> http://www.martin.com/product/product.asp?product=cycloip65series
> So I want to make 2 wireless artNet nodes, where I could skip the dmx part.
>

> //Bj�rn