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by jbeale
Fri Oct 13, 2017 5:49 pm
Forum: Java
Topic: ALSA - AudioSystem.isLineSupported FAILS with USB MIC
Replies: 2
Views: 194

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: 208

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: 16
Views: 13907

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: 346

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: 346

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: 599

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: 599

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: 710

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: 710

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: 16
Views: 13907

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: 972

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: 972

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: 972

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: Cases
Topic: Aluminum enclosure for Raspberry Pi
Replies: 41
Views: 15472

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
by jbeale
Sun May 28, 2017 11:30 pm
Forum: Camera board
Topic: RPi Cam Web Interface
Replies: 4321
Views: 818924

Re: RPi Cam Web Interface

I've done a lot of R-Pi camera projects and building your own dashcam might be a fun project but if you don't have a considerable number of hours available, you're probably better off getting a "real" dashcam. See also: https://dashcamtalk.com/ Personally I like this one: https://dashcamtalk.com/mob...
by jbeale
Tue May 23, 2017 5:55 am
Forum: Camera board
Topic: Trying to get 5Mp .bmp
Replies: 14
Views: 2306

Re: Trying to get 5Mp .bmp

I'd be curious to know what the actual I2C commands you send were. I tried one set which did not work, at least no signal appeared on FREX when I tested it. I don't remember now how I did it, but I think I managed to send the command from the RPi itself. Maybe I misremembered though.
by jbeale
Mon May 22, 2017 9:14 pm
Forum: Camera board
Topic: Trying to get 5Mp .bmp
Replies: 14
Views: 2306

Re: Trying to get 5Mp .bmp

Got working FREX and global shutter release fine both via i2C and FREX exposed cameras. I use external light source, synchronized with frames and can obtain shorter than 0.1 ms exposure time. https://drive.google.com/open?id=0B_L3I0hxknI6MTlrMUxERzUtUms Very interesting! Are you using the OV5647 se...
by jbeale
Sat May 20, 2017 2:32 pm
Forum: General discussion
Topic: Raspbian with Read-only Root
Replies: 94
Views: 23091

Re: Raspbian with Read-only Root

Trying to follow the instructions in the top post, but hit a snag here: # cd /usr/share/initramfs-tools/scripts # cp local overlay # cp -rp local-premount overlay-premount # cp -rp local-bottom overlay-bottom The last line fails because /usr/share/initramfs-tools/scripts/local-bottom does not exist ...
by jbeale
Fri May 19, 2017 5:41 pm
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1146
Views: 143762

Re: PiKrellCam: motion vector detect + OSD web interface

I've now had several systems fail due to SD card corruption, in some cases perhaps just flash wearout. In my usage, I suspect the SD card is the weakest link in the RPi by orders of magnitude (unless it gets wet, in which case connectors can corrode). I think the safest approach is to use a read-onl...
by jbeale
Fri May 19, 2017 5:26 pm
Forum: Camera board
Topic: full-circle M12 fisheye lens for 1/4 inch sensor?
Replies: 18
Views: 3112

Re: full-circle M12 fisheye lens for 1/4 inch sensor?

In a word, no. Those image sensor size categories (1/4, 1/3 etc) are not standardized, they are only approximate bins or size ranges, and each manufacturer, even each separate product has its own dimensions. There are also often 4:3 and 16:9 aspect ratio sensors, again with the same label but of cou...
by jbeale
Fri May 19, 2017 3:57 pm
Forum: General discussion
Topic: Raspbian with Read-only Root
Replies: 94
Views: 23091

Re: Raspbian with Read-only Root

Excellent work. For my first few years of RPi I did not experience SD card corruption, and I did not understand why people complained about it. This past year, having done quite a few deployments using applications doing a lot of file I/O over time, I've had four different SD cards become corrupt, s...
by jbeale
Thu May 18, 2017 8:07 pm
Forum: Camera board
Topic: PiKrellCam: motion vector detect + OSD web interface
Replies: 1146
Views: 143762

Re: PiKrellCam: motion vector detect + OSD web interface

No idea about your specific situation but I can tell you, after about a year of heavy use, one of my PiKrellCam units started having "blackouts" somewhere in the middle of a clip, either a freeze-frame or just a gap typically about 5 seconds long. This was infrequent, maybe 2% of all clips but it ha...
by jbeale
Tue May 16, 2017 8:17 pm
Forum: Camera board
Topic: full-circle M12 fisheye lens for 1/4 inch sensor?
Replies: 18
Views: 3112

Re: full-circle M12 fisheye lens for 1/4 inch sensor?

I'm not aware of any good-quality, true 180-degree FOV camera, either as an optional lens for the R-Pi camera or as a standalone USB camera. You can try searching for example "180 degree USB" in google and see what you get. Amazon does list some USB cameras claiming 180 degrees. The product listings...
by jbeale
Mon May 15, 2017 5:40 pm
Forum: Camera board
Topic: Selecting the right camera module for NIR
Replies: 8
Views: 936

Re: Selecting the right camera module for NIR

I don't know what you've done to get those images but the first image (top one) looks like a false-color or palette-mapped image. When the intensity channel of the displayed image does not match the intensity of the actual detected image (as, for example with false-color palette-mapped images) the p...
by jbeale
Thu May 11, 2017 3:56 pm
Forum: Camera board
Topic: RAW output information
Replies: 234
Views: 59523

Re: RAW output information

On the Raspberry Pi, the camera sensor is always used in RAW mode, so the raw image data is always transferred to the RPi. It is the ISP system onboard the RPi SoC (in the GPU) that does the image processing and creates the JPEG still or H.264 video data. The relative slowness of processing RAW data...

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