Friday, June 28, 2024

Extending USB 3 to Your Imaging Platform, Back to Lac qui Parle, and Amazon Vine Reviewing

I have only the vaguest sense of how USB 2 and 3 differ, but I do know how upgrades can mess up things you have running smoothly. Between mosquitoes and equipment upgrades here is what my relationship with USB has been...

The Shaky Start

In my pre-CCD days I imaged with a DSLR and used PHD for guiding via USB 2 (remember Shoestring Canon-to-USB cables?). The USB 2 sockets on my laptop were so poor that losing connection was a frequent occurrence. Getting Com port numbers sorted was not fun, and I had serious doubts about the technology. 

USB 2: True Love at Last

Everything became USB 2: Mount, imaging camera, guide camera, and eventually electronic focuser. The old laptop was replaced with a new one that had better connection hardware and it all worked wonderfully together. After the 2019 Nebraska Star Party I purchased a portable screened shelter to keep away the bugs, the plan being to use one of the ubiquitous USB 2-over-Ethernet extenders to pass from the shelter to the imaging platform, and it worked. Happiness and bliss were mine!

Coleman 10x10 Skylodge Shelter. It's also useful at night.

Upgrading Woes

Time doesn't stand still; things change. In my case I upgraded imager, guider, and focuser; they all became USB 3. And surprise! The USB 2 extender would no longer be adequate. 

I needed to reach about 15 feet from the shelter to the imaging platform. A USB 3 cable that long is well beyond the suggested length limit, so I needed another solution. There wasn't much to choose from: expensive wireless hubs (ASI Air+ and beyond), DIY-ing together a minicomputer and wifi unit, or a USB 3-over-Ethernet extender hardware solution. I didn't care to spend the $300 or more for wifi and I really didn't want to wade into the issues around adding a minicomputer. And I could not find an Ethernet extender for USB 3. But there was another option...

Active USB 3 Cables to the rescue

Active USB 3 cables use signal amplification to provide greater cable lengths, with the determination of "greater" left to the cable maker. The performance of these seems to be something of a mixed bag. Some people have reported that active cables don't play well with the gear I have from Pegasus and ASI, but I suspect that comes from not supplying power at the imaging (female) end of the cable. The one I bought is 16 feet long, and provides the option for a power input at the imaging end of the cable. 

Active USB 3 cable

The power input posed a wrinkle. Like most active cables the input uses 5V input through a 3.5x1.35mm plug. The source for this power is usually an AC adapter of some sort. This isn't handy in the field unless you have AC--which will not be the case for me. 

My power box is all 12V automotive sockets or Anderson Powerpole connectors, so there's no built-in 5V output. The solution was to use an old 12VDC USB device charger that I had lying around. It's designed to plug into the same automotive sockets that I have on my battery box. Because the charger and active cable combined uses maybe one watt it won't affect my battery's energy budget much at all.

Typical Automotive plug USB charger

What I didn't have is a USB 2 power cable with a 3.5x1.35 plug on it, but Amazon had that, too.
The short cable between charger and active cable

The end of the active cable can be strapped to a tripod leg and then a short USB3 cable runs from it up to my Pegasus Powerbox for distribution.

An indoor test of this with everything running under the guidance of NINA was perfect. The powered cable had no issues with any of my things, Pegasus electronic focuser, ASI 2600 CCD, or ASI120 guide camera. The mount was happy with the USB 2 carried on the cable, too. NINA collected 57 images, and downloaded them all plus continuous PHD2 frames without a single fault. A test under the stars is needed, though, since that will add guiding instructions to the data flow.

This is a timely fix for my upgrades, because at the end of July it's time to go

Back to Lac qui Parle

Yes, despite the storms of my first night there, I've reserved 3 more nights at Lac qui Parle near the end of July.

I can't decide on the imaging target for this jaunt. I should probably finish my Veil mosaic, but I'd rather do that from Eagle Lake. How about a two-panel mosaic of the Lagoon and Trifid Nebulae? Both transit around the time it gets sufficiently dark for imaging, so I can avoid the dreaded meridian flip and the minor glow of Montevideo in the southeast. Given the limited altitude of these targets it will be one one panel per night. 

Do you think I can get two clear nights out of three? Me neither.

Speaking of Amazon....

I've been a regular reviewer of the things we've purchased from Amazon and apparently that tripped their AI into thinking I should be a Vine reviewer. Vine reviewers are the ones who get their reviews tagged with "Vine Customer Review of Free Product." Basically we get products for free in exchange for a timely review. The catch is that the value of the product (as given by its possibly inflated retail price) is treated as taxable income. In my wimpy tax bracket this means almost everything I review is mine at a crazy large discount.

Thank goodness Vine allows me to choose what I will review. Most of the products offered on Vine are things that I probably would never need nor want. For example right now there are 75,468 items available for review. An awful lot of them are odd-looking cases for cell phone models I don't own, silicone ice cube molds, and other things of doubtful value, so a wise reviewer must hunt a little. 

It also helps to not play Amazon's game of trying to be a Gold Tier Vine Reviewer. The gold tier requires one to make a lot of reviews in exchange for being offered items over $100 in value. As one Redditor commented, his obsession with maintaining gold tier status was filling his house with shipping boxes and the stuff that came in them. I'm quite happy to remain a peasant in the silver tier. Actually, if there was a tin tier I'd be cozier in that.

But Vine can be useful because every now and then something of interest gets listed, and if you can grab it before someone else it's yours.

My lust for lithium is leading me to glom onto small LiFePo4 batteries that are great for camping. I've now collected four batteries, and will probably add more. A couple of them will be dedicated to augmenting my laptop's battery. Another will power my camp fan for those hot, breathless days and nights. Depending on how many more of these I score I may bring some up to Northern Nights Star Fest as swap meet fodder. Oops, no. Vine rules say that items must remain mine for six months.

Another Vine offering I may use for astronomy is one of their large table covers. These are waterproof, silvered on one side, and have tie-downs. Does that sound like a tarp for covering an imaging platform? It sure does and for a cost to me of about $10. I'll let you know how it works out.


Table cover fabric (note silver interior lining)


Table cover black side out in conventional use

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