New RDM Sniffer based on the Saleae Logic

[Simon Newton]

bcc: rdm-testing

Over the weekend I put together an DMX/RDM sniffer using a Saleae
Logic device. The software is now in the OLA repo (tools/logic) and
you can read more about it here:

http://www.opendmx.net/index.php/Logic_RDM_Sniffer

It seems to be working well, thanks to Sean and Josh for their help.

Simon

[Jannis Achstetter]

Hi,

Am 24.06.2013 18:34, schrieb Simon Newton:
> bcc: rdm-testing
>
> Over the weekend I put together an DMX/RDM sniffer using a Saleae
> Logic device. The software is now in the OLA repo (tools/logic) and
> you can read more about it here:

That's looking like an awseome project. Well done!

Two questions:
1. Can I use the sniffer as an input device to an OLA universe? So I
just use one logic analyzer and capture 4 universes with it,
re-transmitting them via ArtNet or such?
2. I have one clone of the Saleae since it works with sigrok
(http://sigrok.org/wiki/Fx2lafw). My board is this one:
http://sigrok.org/wiki/Lcsoft_Mini_Board
What firmware is used for the RDM sniffer? Do you think it will work
with my board, too (they're cheap on eB*y :)

Best reagrds,
Jannis

[Simon Newton]

On Mon, Jun 24, 2013 at 10:28 AM, Jannis Achstetter <kri...@gmail.com> wrote:
> Hi,
>
> Am 24.06.2013 18:34, schrieb Simon Newton:
>> bcc: rdm-testing
>>
>> Over the weekend I put together an DMX/RDM sniffer using a Saleae
>> Logic device. The software is now in the OLA repo (tools/logic) and
>> you can read more about it here:
>
> That's looking like an awseome project. Well done!
>
> Two questions:
> 1. Can I use the sniffer as an input device to an OLA universe? So I
> just use one logic analyzer and capture 4 universes with it,
> re-transmitting them via ArtNet or such?

No. I guess one could make a plugin to do that but processing 4 or 8
channels of samples at 4MHz could burn quite a bit of CPU.

> 2. I have one clone of the Saleae since it works with sigrok
> (http://sigrok.org/wiki/Fx2lafw). My board is this one:
> http://sigrok.org/wiki/Lcsoft_Mini_Board
> What firmware is used for the RDM sniffer? Do you think it will work
> with my board, too (they're cheap on eB*y :)

I just use the default firmware. If it works with the SaleaeDevice
library it should work with the sniffer.

Simon

>
> Best reagrds,
> Jannis
>
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[Jason Kyle]

Cool. On the RDM testing front I've been adding to the ultraDMX RDM Pro
firmware recently making it an RDM Responder or 16x RDM Responders (faking
collisions during discovery) so we can ditch using the enttec responder
application. Next addition will be RDM sniffing. How are you presenting the
analysed RDM data with your sniffer?

Jason Kyle
DMXking.com / JPK Systems Limited
j...@dmxking.com

[Simon Newton]

On Mon, Jun 24, 2013 at 2:23 PM, Jason Kyle <ja...@jpk.co.nz> wrote:
> Cool. On the RDM testing front I've been adding to the ultraDMX RDM Pro
> firmware recently making it an RDM Responder or 16x RDM Responders (faking
> collisions during discovery) so we can ditch using the enttec responder
> application. Next addition will be RDM sniffing. How are you presenting the
> analysed RDM data with your sniffer?

The messages are dumped out to the console. It wouldn't be too hard to
make a GUI though.

Simon

[Frederik Nord]

It seems to be working well, thanks to Sean and Josh for their help.

I have tested this, but I don't seem to get any results, even with plain DMX dumping. I have used it in conjunction with the USBDMX Pro and an old DMX controller. I can confirm that data comes into my circuit just fine, the Logic software also can decode the DMX packets (but not RDM of course). I have tried all channels on the logic, no success. Any hints on what's going wrong?

thanks

Felicitus

[Simon Newton]

What version of the Logic are you using?

[Frederik Nord]

> What version of the Logic are you using?

Latest git analyzer, latest logic SDK. However, I am not sure if I have built it correctly. I have passed the SDK as compiler flag to configure, and copied the library to /usr/local/lib and issued ldconfig afterwards.

Thanks
Felicitus

[Simon Newton]

Logic 8 or Logic 16?

[Frederik Nord]

It's a Logic 8.

Regards

Felicitus

2013/11/20 Simon Newton <nom...@gmail.com>

[Frederik Nord]

I've just found the issue - I had improper permissions on the device node. However, the logic rdm sniffer should complain if it can't open the device - it wasn't obvious to me that it doesn't complain.

Thank you for the tool!

Regards

Felicitus

2013/11/20 Frederik Nord <timoa...@gmail.com>

[Sean Sill]

Please let us know how you like! 

[Frederik Nord]

Am Mittwoch, 20. November 2013 18:35:21 UTC+1 schrieb Sean Sill:

Please let us know how you like! 

I like it. However, the tool didn't lead to any success. I have an Arduino RDM library which responds quite nice, at least to my manual debugging. However, the discovery response isn't shown with the analyzer and also not using the DMXUsb Pro RDM utility. Can anybody send me a dump from the Saleae Logic Analyzer (not the CLI tool) so that I can work out where the issue is? That would be very awesome! I don't have any other RDM equipment to cross-test with :(

Regards

Felicitus

[Frederik Nord]

I finally have found the issue! My RDM Device is based on the Arduino RDM Library (http://www.mathertel.de/Arduino/DMXSerial2.aspx). The library is not bad, but it didn't respond to E120_DISC_UN_MUTE or E120_DISC_MUTE commands, thus controllers wouldn't accept them as devices.

Regards

Felicitus

2013/11/21 Frederik Nord <timoa...@gmail.com>

[Simon Newton]

On Wed, Nov 20, 2013 at 8:03 AM, Frederik Nord <timoa...@gmail.com> wrote:
> I've just found the issue - I had improper permissions on the device node.
> However, the logic rdm sniffer should complain if it can't open the device -
> it wasn't obvious to me that it doesn't complain.

I've changed to code to display a message if no device is found.

Simon

[Christian Hortolland]

Hello everyone,
I use Logic 4 interface to make measurements on a DMX512 frame, I inserted a small adapter to pick up the signals (see photo), and for the moment I have no problem (see screenshot).
What is the risk if I don't put a galvanic isolation (as in the proposed interface) but if I take care to recover D + and gnd ? Is there an electrical risk, or to disturb the DMX frame ?
Best regards.
Christian

[Sean Sill]

  You can use the logic on the D-, D+ plus but it may not represent correct timing as you are sampling the differential line. As well as the EIA-485 standard allows D+ up to 12V. You don't see this much in practice but its prudent to note that the logic is only rated up to 5V. In a real world situation you can get spikes and line voltage crosses. I designed the proposed board so you could power it via usb and your logic via usb and connect to any system without knowing what was in it, and it would protect all of your gear including your laptop from bad lines (Random back feed from bad grounds or ground loops /Line voltage enemas, etc)

Does that answer your question?

[Christian Hortolland]

Thank you very much Sean for your answer.

Christian