[-] [email protected] 1 points 1 month ago

I can't change the thickness. I might try cross hatching the ground plane (suggested in the SE) and seeing how that affects the impedance as well.

[-] [email protected] 1 points 1 month ago

It's a USB adapter for a dock. It has a nonstandard pinout, so I made an adapter for it.

7
submitted 1 month ago* (last edited 1 month ago) by [email protected] to c/[email protected]

Does anyone have any advice on routing some high speed signals on flex PCBs? I'm looking at jlcpcb because of the low cost but I'm having difficulty getting impedances to be decent.

My requirements are:

  • 45 ohm single ended impedance (maybe? Def doable)
  • 90 ohm differential impedance (usb spec)
  • 5A current on power pins

But if we look at the capabilities: https://jlcpcb.com/capabilities/flex-pcb-capabilities

  • 2 layer
  • substrate thickness (PI) = 25 um
  • 1 oz pour thickness = 35 um
  • min trace width/spacing = 4/4 mil = 0.101/0.101 mm
  • ε = 3.3

Is this feasible with this stackup? I'd like to do a 1 oz pour because of power traces, but there's also 0.5 oz (18um) and 0.33 oz (12um).

For the differential signals, when I'm doing impedance calculations, I can get to roughly 70 ohms using W=100um, S=200um. I don't think this is good enough. I think I can get away using a 0.33 oz pour but then I'm worried about the power pins.

And for the power traces, I'm needing 2.2mm, which is reasonable for the pins on a USB-C connector. But if I try using the 0.5 oz or 0.33 oz pour, it gets to be 4.2 mm and 6.3 mm, which seems impossible given the pins are tiny and very closely spaced together. Even with vias to the bottom layer, this seems problematic.

Anyone have any advice here? This is just for a hobby project, so I'm really not looking to change fabs because of costs.

[-] [email protected] 5 points 1 month ago* (last edited 1 month ago)

I'm not sure off-hand since I'm not too familiar with VLC.

I would imagine it could be an issue in a graphics driver at the kernel (amdgpu?) or user level (mesa?). It could also be a problem in something higher up.

I would recommend posting an issue in the VLC repo and see if you can get better support that way.

[-] [email protected] 14 points 1 month ago

Can you turn off hardware decoding and see if it works then?

https://wiki.videolan.org/VLC_HowTo/Hardware_acceleration/

[-] [email protected] 51 points 9 months ago

Nope, Lemmy is just as toxic as Reddit imo.

[-] [email protected] 1 points 10 months ago

I'm using it, as well as my boss!

[-] [email protected] 0 points 10 months ago

Remove the videos you dislike from your history

[-] [email protected] 1 points 10 months ago

Maybe marginally. It's pretty easy already to take an old tire off, especially on the machine.

Putting a new tire on is always the hard part imo. I usually let mine sit in the sun for an hour before mounting it.

[-] [email protected] 10 points 10 months ago* (last edited 10 months ago)

It started off okay, but I'm about to give up on Lemmy after a couple months.

My main problems are:

  • The comments here are hit-or-miss. Every big thread deteriorates into pedantic arguments. It's seemingly a worsening trend and is on-par with the bullshit you'd see on Reddit.
  • Lack of comment moderation in larger communities. If a thread devolves into off-topic arguments or name-calling, the mods should step in.
  • The default active post sort is pretty terrible in so many ways. It's much too slow to change and you'll often see repetitive content. Smaller communities tend to have no visibility, but instead I see 5 posts from the same large community.
  • The comment sort is bad as well. If the community self-moderates through downvoting, then why are downvoted posts near the top? I think this leads to toxic threads and pointless arguments.
  • Lack of any content. I wouldn't mind a bot reposting an RSS feed or something into a community just to start discussion... But many are vehemently against that idea (leading to small communities dying completely). I'd argue the reason [email protected] hasn't died out yet is because of the l4s bot.
  • Way too many politics. I'm so tired of seeing political discussion online---but here, you're just bombarded with it, even outside of political communities. Better moderation might help keep things on topic.
  • Users tend to browse All. While this gives people an opportunity to see new content, I think this might harm smaller communities in the long run. This is similar to how threads lose quality once they reach the front page on Reddit.

Maybe I'll come back after a year and see how things are. But as of now, Lemmy provides nearly zero value to me.

[-] [email protected] 12 points 10 months ago
[-] [email protected] 1 points 10 months ago* (last edited 10 months ago)

I'm just over politics on the Internet communities. It's exhausting and becoming increasingly difficult to avoid.

It's not about being centrist or whatever: I have my side and strangers on the Internet aren't going to change that. I don't want to come to Lemmy or Reddit or whatever platform just to be bombarded by pointless political fights. I deal with that enough in the real world.

I don't believe that getting into e-fights over one's political view changes anybody's view on the world---if anything, it makes people more intolerant of one another. I don't understand why people don't use that energy towards something meaningful.

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poopsmith

joined 1 year ago