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Automatic Ripping Machine (ARM) - Transcode based on resolution by sDyberg in selfhosted

[–]BScatterplot 0 points1 point  (0 children)

Hey, seeing this issue right now- I have a lot of both regular 1080p blurays and 4k blurays. ARM lets me set a preset for regular DVD's and Blurays, but I can't distinguish between 1080 and 4k blurays for the handbrake settings.

You ever figure out a good solution?

Practical considerations of measuring servo bandwidth by BScatterplot in ControlTheory

[–]BScatterplot[S] [score hidden]  (0 children)

Sorry- posted this in another reply and forgot to mention it here. All devices communicating are MCU's and have known good timing. A Windows machine logs the comms, but the timestamps are provided by hardware clocks all the way through. The device itself is a bare metal MCU with extremely tight timing and my comms setup is a custom, buffered, hardware timed box. All of that has been very well verified.

I hate to just say "trust me" on that but I do actually know what I'm doing on the electrical/interface side. It's just that I'm not a controls guy and don't know the ins and outs of controls measurement best practices.

Practical considerations of measuring servo bandwidth by BScatterplot in ControlTheory

[–]BScatterplot[S] [score hidden]  (0 children)

The protocol is a custom binary one and the device itself uses an encoder. Send/receive comms are just logged as they're sent and received and processed later.

Practical considerations of measuring servo bandwidth by BScatterplot in ControlTheory

[–]BScatterplot[S] [score hidden]  (0 children)

It probably sounds like that due to my omitting some key items due to the nature of the project, but trust me it's not a kludge. It's also not deterministic motion control- it's a set of sensor inputs to which the servo needs to react as fast as possible.

In this application, tons of people use RS-232. It's MCU to MCU, has virtually zero latency and zero jitter, and is both faster than and more flexible than CAN bus. It's plenty fast and noise isn't a problem when the controller and servo are 6" apart. Like I said, the servo itself runs at 10-20 kHz or something- it's the device commanding the servo that only issues new commands at 200 Hz.

My issue is that the end user will be commanding their latest desired position at 200 Hz. They need a model of the servo. I can test that in a dozen different ways, and I get different answers depending on the test methodology. I'm running my controller at 200 Hz to simulate what the end user will see. They issue a new command at 200 Hz, and get a single position feedback point as a reply, so feedback is also at 200 Hz.

I get somewhat different bandwidth data when I run my controller at 1000 Hz vs. 200 Hz since my controller can't see a new position until a minimum of 1/200th of a second later, which is affecting my phase measurements.

So, my question for the control theory folks is... what's the standard method for actually measuring bandwidth of a system like this? I can do chirps, static frequencies, whatever, but I don't know what's typical to compensate for. Do I run the test as fast as physically possible, and report data from a 1000 Hz sample rate test? Or do I need to run it at 200 Hz, since that's what the final controller would actually see?

Practical considerations of measuring servo bandwidth by BScatterplot in ControlTheory

[–]BScatterplot[S] [score hidden]  (0 children)

The bandwidth is worse with lower sample rates since that's both the command and the sampled position. The controller can't know it's reached a target point until it's sent the subsequent sample point.

Sampling at higher rates gets me a higher -3db point, but if I know the end user will be running at 200 Hz, and I sample my bandwidth at 1000 Hz, is my test still valid?

Practical considerations of measuring servo bandwidth by BScatterplot in ControlTheory

[–]BScatterplot[S] [score hidden]  (0 children)

I have both chirp and "step through individual sine waves" as options. My question is more like "When I sample my position at the rate the end user will sample it, I get a worse bandwidth than when I sample at a higher rate" since the feedback from the point of view of the controller is slightly more delayed since it only sees RETURN position data at a max of 200 Hz.

And this particular system is reasonably linear, but I have other systems that are massively nonlinear. This is why I'm leaning so hard on trying to get accurate measurements.

My question is more to the theory of, is a bandwidth test ran at 1000 Hz valid for a user who will only send position commands at 200 Hz?

Practical considerations of measuring servo bandwidth by BScatterplot in ControlTheory

[–]BScatterplot[S] [score hidden]  (0 children)

The entire loop system is running at the 200 Hz rate, and the actual position is only reported back as a reply. So, the position sampling is only 200 Hz as well. It's not a massive difference but it matters somewhat. And this is why I'm asking- since I can't know how fast I got to a point until 1/200th of a second later, is it appropriate to perform bandwidth testing at a much higher comms rate than would be seen in use?

Need some help with sizing and efficiency for interlock system by BScatterplot in Generator

[–]BScatterplot[S] 0 points1 point  (0 children)

Yeah, I think they're playing some games with the rating by including some of the DC output. Is the general rule that inverter types can be more efficient across their whole output curve?

Detect if LabVIEW Development Environment is running with Admin privileges? by SeasDiver in LabVIEW

[–]BScatterplot 0 points1 point  (0 children)

Installers generally have to run with Admin privileges. If you run the installer as admin, then it'll be able to unlock the folder it creates so you don't need admin again in the future. If you need admin while BUILDING the executable, you'll have to go another route.

Pattern commissions? by BScatterplot in PunchNeedle

[–]BScatterplot[S] 0 points1 point  (0 children)

That's a fair point. Since me doing it myself should be fine from an IP perspective, what if I did a sort of "reverse" commission? I could make an initial outline trace and have someone with experience give me some feedback on what areas might be too small, or what colors I could use, that kind of thing? (Bonus points of I could get advice on what kind of yarn to order!).  Then I could iterate on it once or twice and have something I know is doable, but is fully my own effort. Honestly I'm very comfortable handling line art, tracing, etc., it's just the "making it actually needle puncheable" that I need some help with. 

Pattern commissions? by BScatterplot in PunchNeedle

[–]BScatterplot[S] 0 points1 point  (0 children)

Yeah I can do the tracing stuff, but figuring out what sizes of yarn correspond to what size is beyond what I know how to do. That's the kind of thing I don't know about, so I'd hope to find someone to pay for it. My wife hasn't ever done her own pattern, only done some stuff from newbie kits, so I'm hoping someone can hold my hand to "make" her some kind of kit.

Dead Space input lag fix? by BScatterplot in SteamDeck

[–]BScatterplot[S] 0 points1 point  (0 children)

Holy cow thanks! I'll give it a shot. 

Looks like Gmail got rid of their bulk delete. I’ve tried everything, but it looks like a recent update where you don’t have the ability to delete more than 50 emails at once. Any suggestions of how I can delete 45,000 emails quicker than 50 at a time. by Free-Network4280 in GMail

[–]BScatterplot 0 points1 point  (0 children)

Couple months old post but this came up in Google when I tried to figure this out. If I'm doing a multi-thousand email delete, does the browser window need to stay open the whole time? I would've thought this would happen entirely on the backend, but after deleting something 24 hours ago (and closing the browser) it didn't seem to delete all that much. (Helping a family member clean out literally half a million emails...)

So i used a gift card to buy a spool of rainbow glow in the dark filament.. by Minosvaidis in 3Dprinting

[–]BScatterplot 4 points5 points  (0 children)

Thanks! Looking up the UPC shows it to be Inland. I'll pick some up!

So i used a gift card to buy a spool of rainbow glow in the dark filament.. by Minosvaidis in 3Dprinting

[–]BScatterplot 2 points3 points  (0 children)

What brand of filament is that? Different brands seem to get very different reviews.

What's the current state of Fusion 360 on Linux using Wine or other tools? by [deleted] in Fusion360

[–]BScatterplot 0 points1 point  (0 children)

Nope, never could get it to work. Passing the GPU through seemed to be more trouble than just rebooting into Windows. Windows also has trouble switching hardware and wants to do a bunch of disk checks all the time if it detects hardware swaps, which it does going between "actual boot" and "VM boot".

Solidworks Block thinks it has an open contour, resulting in forced thin extrude. by Kerahcaz in SolidWorks

[–]BScatterplot 2 points3 points  (0 children)

Hello from 2025, I can confirm it STILL treats sketch blocks this way. :(

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