Go to advanced search

by jbeale
Mon Oct 30, 2017 2:05 pm
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

what causes camera to not take picture sometimes?

I just set up a different system and power supply from the Pi I just posted about. Installed pikrellcam from git yesterday, so it is current code. This one has an external motion sensor connected to a GPIO and I have my own process watching the GPIO and sending a command into the Pikrellcam FIFO "ec...
by jbeale
Mon Oct 30, 2017 5:22 am
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

Re: PiKrellCam: motion vector detect + OSD web interface

Ah, you make a good point about the power supply. I didn't think of that this time, but it's good to check- as I recall this one was pretty cheap and I've had others go bad before.
by jbeale
Sun Oct 29, 2017 5:27 pm
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

Re: PiKrellCam: motion vector detect + OSD web interface

After about a year of working OK, one of my pikrellcam units gets a frozen camera image every 1 or 2 days. The RPi itself is still running OK and I can browse earlier captures, but the live camera is frozen and nothing new can be recorded. Rebooting gets it going again. I assume there is some interm...
by jbeale
Thu Oct 26, 2017 8:49 pm
Forum: Camera board
Topic: OpenCV feature tracking example
Replies: 21
Views: 22236

Re: OpenCV feature tracking example

Thanks for that update and I'm glad it's working for you! I have been doing other things meanwhile, but now I'm curious to revisit this code.
by jbeale
Thu Oct 26, 2017 3:29 am
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

Re: PiKrellCam: motion vector detect + OSD web interface

Thank you, yes that was it! Now it is working again, I am very relieved. I have another system with a failing SD card, now I can upgrade it to the new version.

thanks again,
John
by jbeale
Thu Oct 26, 2017 12:05 am
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

Re: PiKrellCam: motion vector detect + OSD web interface

I see that the nginx config file /etc/nginx/sites-available/pikrellcam includes the line fastcgi_pass unix:/var/run/php5-fpm.sock even though this is now using PHP7. I don't know what this means; on the off-chance, I changed this line to "fastcgi_pass unix:/var/run/php/php7-fpm.sock" but that didn't...
by jbeale
Wed Oct 25, 2017 9:49 pm
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

Re: PiKrellCam: motion vector detect + OSD web interface

Many thanks for that lightning-quick fix! I tried a fresh install of the full desktop Raspbian Stretch on a RPi-2, and then the git pikrellcam stage. I was able to install without seeing any errors. I rebooted and I see pikrellcam is running with about 5% of CPU, so that much may be OK. However when...
by jbeale
Wed Oct 25, 2017 3:27 am
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1427
Views: 287266

Re: PiKrellCam: motion vector detect + OSD web interface

I cannot install pikrellcam on current Raspbian Stretch Lite system from https://www.raspberrypi.org/downloads/raspbian/, as you see below. Looks like php5 is not available? Do I have to use php7? Any recommendations? [email protected]:~/pikrellcam $ uname -a Linux rp4 4.9.41+ #1023 Tue Aug 8 15:47:12 BST 2017...
by jbeale
Mon Oct 23, 2017 8:04 pm
Forum: Camera board
Topic: OpenCV feature tracking example
Replies: 21
Views: 22236

Re: OpenCV feature tracking example

This post is two years old and I haven't touched it since then. I assume you are using this code: https://github.com/jbeale1/OpenCV/blob/master/motion3.py I do recall getting video output recorded but please note this was on a windows PC, not a R-Pi. The AVI video container format is associated with...
by jbeale
Wed Oct 18, 2017 8:59 pm
Forum: Graphics programming
Topic: OpenCL on the VideoCore IV!
Replies: 82
Views: 52536

Re: OpenCL on the VideoCore IV!

Thanks for that informative reply. I assume the difference between the 4 GFlops in practice and 24 GFlops in theory, has to do with memory bandwidth?
by jbeale
Wed Oct 18, 2017 4:26 pm
Forum: Graphics programming
Topic: OpenCL on the VideoCore IV!
Replies: 82
Views: 52536

Re: OpenCL on the VideoCore IV!

This sounds very impressive but I'm not sure I understand the implications. Are there any examples of this in action? Does this mean we might be able to get better performance on compute-intensive tasks, like image recognition? Right now there are neural-network "deep learning" based object-detectio...
by jbeale
Fri Oct 13, 2017 5:49 pm
Forum: Java
Topic: ALSA - AudioSystem.isLineSupported FAILS with USB MIC
Replies: 2
Views: 1563

Re: ALSA - AudioSystem.isLineSupported FAILS with USB MIC

Sorry I can't assist, I have never tried developing in Java on any platform. The only things I've done on RPi like this is recording audio from a USB webcam with 'arecord' and also separately with 'ffmpeg' as described here: https://lb.raspberrypi.org/forums/viewtopic.php?t=153520#p1006200 If you ca...
by jbeale
Wed Sep 13, 2017 2:07 am
Forum: Camera board
Topic: Zoom/Replacemant lense
Replies: 1
Views: 660

Re: Zoom/Replacemant lense

First off, there are no zoom lenses native to the RPi camera. You will have to retrofit a M12 mount (or buy one of the RPI-Version 1 compatible cameras from 3rd parties that already have the M12 mount). Second, there are quite a few M12 mount zoom lenses, nearly all intended for the 1/3-inch format ...
by jbeale
Fri Sep 08, 2017 4:13 pm
Forum: Camera board
Topic: Understanding the Pi Camera with a M12 lens/mount
Replies: 21
Views: 36418

Re: Understanding the Pi Camera with a M12 lens/mount

I'm not aware of any that I would call "sharp". Here's a RPi-compatible lens that's pretty close to 180 degrees: https://www.raspberrypi.org/forums/viewtopic.php?t=158545&p=1164934#p1039847 It is definitely not sharp across the field, but still usable for some things, and it's about as good as I've ...
by jbeale
Wed Sep 06, 2017 9:39 pm
Forum: Graphics, sound and multimedia
Topic: USB audio adapter / soundcard with stereo INPUT?
Replies: 2
Views: 3650

Re: USB audio adapter / soundcard with stereo INPUT?

Thanks, good to hear that one is working well.
by jbeale
Wed Sep 06, 2017 5:53 pm
Forum: Graphics, sound and multimedia
Topic: USB audio adapter / soundcard with stereo INPUT?
Replies: 2
Views: 3650

USB audio adapter / soundcard with stereo INPUT?

There are many small USB audio adapters sold with stereo output jack for headphones and mono mic input. Are there any small cheap USB soundcard devices like that with stereo line INPUT ? I'm having a hard time finding any. Search is difficult because all of them claim "stereo" but that apparently is...
by jbeale
Tue Sep 05, 2017 5:38 pm
Forum: Graphics, sound and multimedia
Topic: good quality USB audio mic input ?
Replies: 4
Views: 3801

Re: good quality USB audio mic input ?

Thanks for that link. Indeed, that saying is often true. I mentioned the PS3 Eye as a striking counterexample, because it has good audio quality for $7 shipped: https://www.amazon.com/Sony-PlayStation-Eye-Camera-Bulk-Packaging/dp/B0072I2240 I was curious if anyone knew of a similar deal on something...
by jbeale
Tue Sep 05, 2017 2:24 pm
Forum: Graphics, sound and multimedia
Topic: good quality USB audio mic input ?
Replies: 4
Views: 3801

good quality USB audio mic input ?

Does there exist an inexpensive USB audio interface that works on the R-Pi with a good quality mic-level input? I have a no-name usb-audio dongle from ebay, super cheap at $5 but has a rather noisy and distorted input. I've seen >$100 add-on board solutions using I2S which are I assume good. Is ther...
by jbeale
Tue Sep 05, 2017 2:22 am
Forum: Beginners
Topic: Raspberry Pi wired 150ft connection
Replies: 20
Views: 2738

Re: Raspberry Pi wired 150ft connection

Hmm, I suggested PoE but I hadn't thought about the safety aspect. This does happen, google "swimmer electrocuted" https://www.cbsnews.com/news/parents-warn-about-electric-shock-drowning-after-15-year-old-girls-tragic-death/ https://www.usatoday.com/story/news/nation-now/2017/06/21/girl-11-electrocu...
by jbeale
Fri Sep 01, 2017 3:50 pm
Forum: Beginners
Topic: Raspberry Pi wired 150ft connection
Replies: 20
Views: 2738

Re: Raspberry Pi wired 150ft connection

Standard 802.3af POE (power over ethernet) can deliver 13 watts (+48V at 0.3 A), and 802.3at, or POE Plus delivers 25 watts. If this is a very small and slow sub that might be enough. For more power you'd want batteries onboard. However, AFAIK standard ethernet cable is not designed for use underwat...
by jbeale
Mon Aug 28, 2017 12:03 am
Forum: Camera board
Topic: Understanding the Pi Camera with a M12 lens/mount
Replies: 21
Views: 36418

Re: Understanding the Pi Camera with a M12 lens/mount

If you retrofit your pi camera with a M12 lens mount, then yes a M12 lens should work on it. I have done this and it works. Don't expect the same image quality as with the stock pi lens though. If you need longer lenses you can do much better for slightly more money with an IP security camera. These...
by jbeale
Tue Aug 08, 2017 11:22 am
Forum: General discussion
Topic: why is my ethernet cable magnetic?
Replies: 10
Views: 2084

Re: why is my ethernet cable magnetic?

Except if you are using PoE over a longish run to also power a device...
by jbeale
Sun Jul 16, 2017 3:19 am
Forum: General discussion
Topic: why is my ethernet cable magnetic?
Replies: 10
Views: 2084

Re: why is my ethernet cable magnetic?

Yes, although I thought the good cables were solid copper, and the cheap stuff would be copper-clad aluminum. Steel wire had not occurred to me.
by jbeale
Sun Jul 16, 2017 2:26 am
Forum: General discussion
Topic: why is my ethernet cable magnetic?
Replies: 10
Views: 2084

why is my ethernet cable magnetic?

Was playing around with a magnet today and to my surprise, I can pick up one of my ethernet patch cables with the magnet. Copper, aluminum, and plastic don't do that, so it must contain steel wire? Is this common? None of my other cables do this. The magnetic cable is light grey or tan in color and ...
by jbeale
Wed May 31, 2017 4:02 pm
Forum: Other projects
Topic: Aluminum enclosure for Raspberry Pi
Replies: 42
Views: 34773

Re: Aluminum enclosure for Raspberry Pi

dirthurts wrote:I would be more interested if only the top was aluminum, and the rest plastic. It would be more affordable, and if you finned it out more it should perform just as well.
That's been done here, although it doesn't look as cool: viewtopic.php?f=40&t=169107

Go to advanced search