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by cpunk
Mon Jul 24, 2017 10:00 am
Forum: Camera board
Topic: Kernel/scheduler affecting "raspivid" behaviour?
Replies: 2
Views: 965

Kernel/scheduler affecting "raspivid" behaviour?

I have a somewhat strange observation. I originally developed my aerial robot application (still nowhere near flying) on a Pi 3 with the 4.9.35 kernel. Then, after discovering that Pi4J had problems with that kernel, I downgraded to 4.4.45. I have two processes reporting FPS (frames per second) in m...
by cpunk
Mon Jul 24, 2017 9:48 am
Forum: General discussion
Topic: Pi Zero W availability
Replies: 110
Views: 19556

Re: Pi Zero W availability

I'm also keeping my eyes open with regard to Pi 0 W availability, and I would like to second the opinion that it's *not* the best teaching device. There are multiple reasons for that: - Lack of multiple USB ports. - There are far fewer miniHDMI displays around. - No Ethernet connector. - No speaker/...
by cpunk
Thu Jul 20, 2017 8:41 pm
Forum: Camera board
Topic: Object and Feature Recognition
Replies: 2
Views: 991

Re: Object and Feature Recognition

OpenCV is neat, and I've worked with it, though not on a Pi, but a generic Debian system with and Atom CPU. To say the least, it was slow... and it's no secret that vision needs high-end processors, which Atom is definitely not... and neither is Raspberry Pi's tiny CPU (although 4 cores is nice). Th...
by cpunk
Thu Jul 20, 2017 7:30 pm
Forum: AIY Projects
Topic: audio doesnt work at all
Replies: 15
Views: 13876

Re: audio doesnt work at all

I'm sorry, I can't figure this out... despite retracing all the steps that I did today, as much as I can remember... I cannot get from the working state to the broken state, so I can't pinpoint what broke it. I just have one memory card image that's working and another that's broken, and no idea how...
by cpunk
Thu Jul 20, 2017 6:26 pm
Forum: AIY Projects
Topic: audio doesnt work at all
Replies: 15
Views: 13876

Re: audio doesnt work at all

It does not seem to be a modules problem either... when I issue "lsmod", then among others, both on the working and broken system, I have: snd_bcm2835 24427 0 snd_pcm 98501 1 snd_bcm2835 snd_timer 23968 1 snd_pcm snd 70032 3 snd_timer,snd_bcm2835,snd_pcm
by cpunk
Thu Jul 20, 2017 5:59 pm
Forum: AIY Projects
Topic: audio doesnt work at all
Replies: 15
Views: 13876

Re: audio doesnt work at all

I have another system with the 4.9.35 kernel where audio works, so it's not the kernel... I'm running out of ideas.
by cpunk
Thu Jul 20, 2017 5:03 pm
Forum: AIY Projects
Topic: audio doesnt work at all
Replies: 15
Views: 13876

Re: audio doesnt work at all

I'm currently suspecting that it's due to the same change (kernel reporting different chipset version string) that broke pi4j. But that's just a guess. I'm currently cloning a known-good configuration to compare the working and broken one... (which modules loaded, which modules are blacklisted, etc).
by cpunk
Thu Jul 20, 2017 3:21 pm
Forum: AIY Projects
Topic: audio doesnt work at all
Replies: 15
Views: 13876

Re: audio doesnt work at all

Update: I have now tried reinstalling the "raspberrypi-kernel" and "raspberrypi-bootloader" packages, and for me, that doesn't help (error messages are the same as before). I suspect this happened due to the upgrade to the new kernel, but I can't point to anything specific yet. Will post if I figure...
by cpunk
Thu Jul 20, 2017 3:11 pm
Forum: AIY Projects
Topic: audio doesnt work at all
Replies: 15
Views: 13876

Re: audio doesnt work at all

My situation started matching yours recently (in fact, today). Previously my system worked, but after I ran "apt-get update; apt-get dist-upgrade" today, to bring everything up to date, and the downgraded kernel (due to some pi4j issues), I no longer get audio, and "alsamixer" and "aplay" as well as...
by cpunk
Thu Jul 20, 2017 1:54 pm
Forum: Troubleshooting
Topic: "Unable to determine hardware version"
Replies: 31
Views: 40647

Re: "Unable to determine hardware version"

Also experienced this today. My platform was as follows: uname -a Linux raspberrypi 4.9.35-v7+ #1014 SMP Fri Jun 30 14:47:43 BST 2017 armv7l GNU/Linux Results: - For me, updating to the latest *precompiled* pi4j snapshot does not help. Maybe their binary snapshots are out of date as of today (2017-0...
by cpunk
Tue Jul 18, 2017 5:35 am
Forum: Camera board
Topic: Camera is very fragile! Lenses coming off
Replies: 5
Views: 1207

Re: Camera is very fragile! Lenses coming off

Ouch. Sad to hear of the damage. I carry a single version 1.3 camera, attached using a 15 cm flat cable to a Pi 3 (which is in turn connected with screws to the cheapest 5" touch screen from China) in the side pocket of my backpack. Basically, the camera is dangling loose within the confines of the ...
by cpunk
Mon Jul 17, 2017 8:49 pm
Forum: Camera board
Topic: raspivid motion vectors
Replies: 7
Views: 1900

Re: raspivid motion vectors

Just tested... given my conditions, messing with brightness and contrast is vastly preferable to setting a shutter speed. Shutter speed causes lamps to flicker despite the anti-flicker option being set, presumably because it overrides that... brightness and contrast occur as post-processing and don'...
by cpunk
Mon Jul 17, 2017 8:22 pm
Forum: Camera board
Topic: Help to find image sensor
Replies: 3
Views: 839

Re: Help to find image sensor

Maybe a scanning camera actuated by a stepper motor? :D
by cpunk
Mon Jul 17, 2017 8:17 pm
Forum: Camera board
Topic: raspivid motion vectors
Replies: 7
Views: 1900

Re: raspivid motion vectors

Yes, saturation problems I've already seen. :) What is curious to me, is that despite them, I get higher quality motion estimation, even if the image quality is nowhere near cheerful. :) For example, I'm currently looking at a grayed-out frame with contrast and brightness totally out there... and it...
by cpunk
Sat Jul 15, 2017 10:22 pm
Forum: Camera board
Topic: RESOLVED: Macro-block buffering
Replies: 26
Views: 4822

Re: RESOLVED: Macro-block buffering

Thanks for the info. :) ...and now that I think of it, only by also testing outdoors, can I find out if switching off automatic exposure was a practical thing to do. I'll try to get there (dangling the drone from a fishing pole or something, no flying yet) in a week or two. :)
by cpunk
Sat Jul 15, 2017 2:59 pm
Forum: Camera board
Topic: RESOLVED: Macro-block buffering
Replies: 26
Views: 4822

Re: RESOLVED: Macro-block buffering

Out of curiosity, what are you using for the "-ex" option, Hove? I only today found out that "-ex auto" causes (again via changes in brightness) motion vectors to be generated which do not represent real motion (just like lamp flicker does). After setting it to "off" instead of "auto" (and establish...
by cpunk
Sat Jul 15, 2017 2:37 pm
Forum: Camera board
Topic: QR Code Scanner compatible for RPi 3
Replies: 21
Views: 26391

Re: QR Code Scanner compatible for RPi 3

I personally cannot recreate it... zbar-tools installs correctly here.
by cpunk
Sat Jul 15, 2017 1:45 pm
Forum: Camera board
Topic: raspivid motion vectors
Replies: 7
Views: 1900

Re: raspivid motion vectors

Sorry for double-posting, but I'll also mention this in the thread that Hove started, to ask if he's already using this (since drone-flying people would likely be especially interested in getting undesired noise out of motion vectors)... ...but here's what I found: automatic exposure produces noisy ...
by cpunk
Thu Jul 13, 2017 10:03 pm
Forum: Camera board
Topic: QR Code Scanner compatible for RPi 3
Replies: 21
Views: 26391

Re: QR Code Scanner compatible for RPi 3

I have used the zbar library in an Android environment (from Java), and I would also recommend it, but sadly I don't have samples. I haven't done any barcode work with a Pi until now. But one thing: don't use a too big frame size, otherwise zbar will slow to a crawl. Most barcodes can be decoded nic...
by cpunk
Thu Jul 13, 2017 9:51 pm
Forum: Camera board
Topic: Hummingbird stills
Replies: 7
Views: 1611

Re: Hummingbird stills

Hummingbirds have very fast-beating wings. :) So yes, software might be able to discern a hummingbird from other birds... ...with a fairly good rate of false positives and false negatives... meaning, it would likely not detect swans or eagles, and neither would it detect fruit flies or bees, but it ...
by cpunk
Thu Jul 13, 2017 9:41 pm
Forum: Camera board
Topic: raspivid motion vectors
Replies: 7
Views: 1900

Re: raspivid motion vectors

Interesting... I have not tried with total darkness, although I am also building an application which consumes motion vectors. I can test the situation you describe tomorrow. I don't know how the encoder is supposed to behave (or if we can influence how it does), but I can at least comment on how it...
by cpunk
Mon Jul 10, 2017 8:35 am
Forum: Camera board
Topic: Camera Cable Length = 15m possible?
Replies: 13
Views: 2885

Re: Camera Cable Length = 15m possible?

Yep, they are simplified boards... but unfortunately, Pi 0 and Pi 0W don't have Ethernet... so it's more like:

camera - Pi 3 - ethernet cable - Pi 3 - display

(this does increase the minimum size of the ROV considerably, which seems unavoidable in this case)
by cpunk
Sun Jul 09, 2017 4:37 pm
Forum: Camera board
Topic: RESOLVED: Macro-block buffering
Replies: 26
Views: 4822

Re: RESOLVED: Macro-block buffering

Took some time (new tools) but pull request created. :) I found a seemingly better place for the structure I had duplicated before, but whether it was the right place, no idea. :)
by cpunk
Sun Jul 09, 2017 2:36 pm
Forum: Camera board
Topic: RESOLVED: Macro-block buffering
Replies: 26
Views: 4822

Re: RESOLVED: Macro-block buffering

Thanks, will do. :) As for the duplication of command line parsing, I'll see how other apps are doing it. For some reason, on first attempt, I couldn't understand it properly.
by cpunk
Sun Jul 09, 2017 2:03 pm
Forum: Camera board
Topic: RESOLVED: Macro-block buffering
Replies: 26
Views: 4822

Re: RESOLVED: Macro-block buffering

Thank you for yet another useful tip! :) I now have code to contribute (besides the ! argument for dumping vectors to "stderr" -- which is indeed bad style, yet incredibly useful to me personally... I understand if nobody wants it into distribution code, though I can offer to add protective code to ...

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