USB extenders revisited - Lantronix UBox

[Stuka]

Back in September, I started a thread talking about the pros & cons of using some of the USB extender products on the market for "stretching out" the USB connection to the Pangolin FB3 and other USB controllers:

http://www.photonlexicon.com/forums/...ead.php?t=3053

I think when it was all said and done, the general consensus was it would be best to find another way to extend the USB connection, and I whole-heartily agree.

I have continued to look for a RELIABLE way to extend a USB connection to my projector (in progress, sort-of!) so I can keep the FB3 card contained in the projector housing. The goal was to control the projector with one inexpensive CAT5 cable connection for the remote beam shutter control box, and a single USB connection from my laptop. I'll also be including a DMX connection option, but that's a discussion for down the road...

Anyway, I discovered and purchased a device that I think will fit the bill for just about anyone that wants to build a projector with their USB controller contained in the same projector housing, and wants to be able to extend the USB connection between their computer and projector. Advantages to this solution are it's laptop-friendly, doesn't require a separate powered control box for the FB3 (or other USB-equpped controller), doesn't require a separate computer positioned remotely with the projector, and can be "stretched" as far as you need using inexpensive CAT5 cable.

DISCLAIMER - I have NOT been testing with scanners & lasers attached to the FB3, but have been relying on the feedback from the software (Pangolin LiveQuick and LivePro) during my testing. So far, not a single hiccup - I'll update once I get scanners hooked up!

The device I'm using is a UBox 2100 2-port remote USB Device Server, from Lantronix http://www.lantronix.com/.
I purchased mine from GridConnect, http://www.gridconnect.com/, for $139.

It's high-speed USB 2.0 compliant, runs off a 5VDC wall-wart power supply (included), and connects back to your computer with CAT5 cable.

Here's a side-by-side comparison with the FB3 card:

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Here's an end thickness comparison:

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As you can see, not much overall size difference, maybe twice as thick, and EASILY mounted on the back panel of a projector with a couple of screws.

For testing, I have my laptop plugged into my home router, the router connected to the UBox with about 25' of coiled CAT5 cable, and the FB3 connected to the UBox with the cable that came with the card. It took about 5 minutes to install and configure the UBox server application on my laptop. The FB3 was recognized by the server application without a hitch:

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Getting up and running is VERY easy - connect and power up everything, run the UBox server application and click the CONNECT icon for the FB3, and fire up the laser controller software! So far, so good with the FB3 and software-only testing - more to follow as I get the chance to check out longer cable lengths and real-time control with lasers & scanners attached.

Randy

[The_Doctor]

Nice. Is it restricted to a LAN? Could be useful if it was internet too, especially for shows that might need a way for an air traffic controller to shut off a beam in an emergency, as well as allow something close to attended control for someone who has to move further away than fixed cabling allows easily, because WAN access can easily be done via secure mobile phone links.

[JeroenVDV]

Nice. Is it restricted to a LAN? Could be useful if it was internet too, especially for shows that might need a way for an air traffic controller to shut off a beam in an emergency, as well as allow something close to attended control for someone who has to move further away than fixed cabling allows easily, because WAN access can easily be done via secure mobile phone links.

Way too slow.. Compare WAN and USB 2.0 speeds (USB 2.0 = 480Mbit/s)..

[The_Doctor]

Wasn't sure how much data had to go through it. I thought the fast stuff would be done by the FB3 at the far end. Isn't it possible to delegate enough of the fast work to that and reduce the amount that must go through the control link to the point where a cable or DSL line is enough even if dial-up type phone links won't be?

[JeroenVDV]

LiveQ will work OK with a real slow network or even the internet (because the FB3 plays the animations using own CPU) and the software only sends a trigger to choose a cue, apply effects, etc.

LivePro and Showrider generate the frames on the computer and send them complete over the connection..

[Stuka]

It's designed as a LAN-connected device, although in today's wireless world that leaves a lot of possibilities open! As long as the server application on the controlling computer can detect the UBox somewhere on the network, you should be good to go - although I could see possibilities where bandwidth COULD be an issue if generating some intense graphics on the controller end.

The "acid test" will come when I get the FB3 hooked up to lasers and scanners, and can start experimenting with LivePro, MIDI controllers, and 50' to 100' CAT5 cable runs. I figure anything much past that probably exceeds what most of us "hobbyist" would utilize, so one would probably be better off with a remote computer (LAN or WAN) and a high-end solution like the LD2000/QM2000 from Pangolin.

For the ease of use and price I paid, I figure if I can consistently go up to 50' or so I'm getting my money's worth! More to follow...

[Laser Ben]

Wow, your FB3 board is a lot different then mine!

[Stuka]

Yeah, my FB3 is an "older" model purchased WAY back in July '07 .
It still uses a SmartMedia card memory slot.

I had heard that were changed to XD memory card slots right after I purchased mine, but I haven't had the chance to see one yet. From the functionality standpoint, I THINK they're still pretty much the same - maybe !

[Laser Ben]

The differences I see are the Power Connector, the USB connector, and some of the component connectors.

[The_Doctor]

Not sure how many bytes are needed to express a point's co-ordinates, but I guess two per channel? At up to 60 kpps that's four or five times faster than dialup modems. Even adding the other controls for RGB intensity it could be within a basic cable connection speed, most cheap ones are ten times faster than dialup. The interpolation between points to smooth the signal for best galvo acceleration can be done in hardware. That's what outputs the biggest stream of data but it's a task best done at the last stage before the DAC. If frames can be simplified, or you don't need such extreme scan rates, it could be easy to do through anything faster than an actual dial-up connection. Even a fast RS-232 might be adequate.

I don't know what limits various systems place on this, but that's my thought on the matter, It is possible over many internet lines, even if in specific cases it isn't doable because interpolation is done in software before the signal reaches the remore hardware. Interpolation is so basic, and needs speed, so it's something a small microcontroller might do, even in the most simple DAC's, if added to them.

Another nice reson for the hardware doing interpolation is that crude point-to-point software might be usable with it and still produce a neater scan. This in turn means there's another advantage: the output of interpreted laguages like Lua can send data fast enough (because the main weak link in Lua or Python, TCL, etc, is they can't do the interpolation fast enough), which opens up a lot of alternative systems for people to try to brew their own systems if it's done on the DAC board. It's never going to be Pangolin but it WOULD be liberating for many.

To tired to debate more now...


Edit: Never mind, upload speeds also matter, and those might still be too restrictive, many are just a quarter of the download speed for cable. I still think the hardware interpolator idea is cool though.