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by mjtrac
Sun Jun 16, 2013 2:18 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: confused by gpio to uln2803
Replies: 8
Views: 7800

Re: confused by gpio to uln2803

Thank you! But now I'm even further confused. If you google raspberry pi uln2803, you'll find an adafruit lesson on using the uln2803 with the pi's gpio to control a stepper motor, as well as ULN2803 boards being specifically sold on ebay for use with the pi. (Later: for anyone checking here, my pro...
by mjtrac
Sun Jun 16, 2013 7:17 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: confused by gpio to uln2803
Replies: 8
Views: 7800

confused by gpio to uln2803

Please bear with me, as will become obvious I am the opposite of an electronics whiz. I'm trying to control a small 12v motor from the pi, using power from a computer power supply while running the pi off a USB wall wart. The motor spins when connected to 12v and ground from the computer power suppl...
by mjtrac
Sat Jun 08, 2013 12:39 am
Forum: Camera board
Topic: Raspistill timelapse. Images get progressively darker
Replies: 117
Views: 32086

Re: Raspistill timelapse. Images get progressively darker

In -ex verylong, I get an identical shot with -t set to 5000 as with -t set to 0. It does not crash with either command line, and the command can be repeated. I won't waste your time with examples.
by mjtrac
Thu Jun 06, 2013 9:27 pm
Forum: Camera board
Topic: Raspistill timelapse. Images get progressively darker
Replies: 117
Views: 32086

Re: Raspistill timelapse. Images get progressively darker

One other thing that could conceivably be relevant is that my pi is one of the earlier model b's with the smaller ram. Doubt that's it, but worth mentioning.
by mjtrac
Thu Jun 06, 2013 9:16 pm
Forum: Camera board
Topic: Raspistill timelapse. Images get progressively darker
Replies: 117
Views: 32086

Re: Raspistill timelapse. Images get progressively darker

I don't think I'm imagining the quality improvement with "-ex verylong" so I am somewhat befuddled. OK, fully befuddled. What befuddles me is that it doesn’t crash for you. verylong used to hang the camera requiring a reboot to get it unstuck. Does it work now? How long does it make the exposure ti...
by mjtrac
Thu Jun 06, 2013 9:08 pm
Forum: Camera board
Topic: Raspistill timelapse. Images get progressively darker
Replies: 117
Views: 32086

Re: Raspistill timelapse. Images get progressively darker

I think I’ve seen that commented out in the code with the ocmment that it is not working. Thanks. Here is the complete list of commands from the RaspiStill.c file at https://github.com/raspberrypi/userland/blob/master/host_applications/linux/apps/raspicam/RaspiStill.c (Added: more commands are in R...
by mjtrac
Thu Jun 06, 2013 8:19 pm
Forum: Camera board
Topic: Raspistill timelapse. Images get progressively darker
Replies: 117
Views: 32086

Re: Raspistill timelapse. Images get progressively darker

Actually, I do see a quality difference with -ex verylong.
verylong.png
-ex verylong
verylong.png (1.89 KiB) Viewed 5763 times
iso1000.png
-ISO 1000
iso1000.png (1.27 KiB) Viewed 5763 times
iso16000.png
-ISO 16000
iso16000.png (1.61 KiB) Viewed 5763 times

(The image is a nose from a snapshot, photographed from about 60 cm away, and seen on a diagonal.)
by mjtrac
Thu Jun 06, 2013 8:14 pm
Forum: Camera board
Topic: Raspistill timelapse. Images get progressively darker
Replies: 117
Views: 32086

Re: Raspistill timelapse. Images get progressively darker

Um, this may be related to the topic at hand. I've tried running raspistill on a static image with arguments -ISO 1000 through 16000 and get exactly the same image each time. I don't really have much of a clue as to what the ISO setting is or should be; I'm wondering if anyone can explain appropriat...
by mjtrac
Mon May 20, 2013 9:50 pm
Forum: Camera board
Topic: some camera spec questions
Replies: 4
Views: 1914

Re: some camera spec questions

Now that I have a camera in hand, I figured I would post a definitive-ish answer to the question I posed. From about 24" away, the camera's field of view is largely but not completely filled with an 8.5 x 11 piece of paper. Even in middling lighting, magazine text (Harper's, maybe 11 or 12 point?) i...
by mjtrac
Sun May 19, 2013 4:39 pm
Forum: Camera board
Topic: netcat on ubuntu
Replies: 1
Views: 1039

netcat on ubuntu

For what it's worth, I ran into problems trying to send a stream from the pi to an Ubuntu Linux machine until I realized that the version of netcat needed, if you are following the provided instructions, is not nc, but /bin/nc.traditional -- it can be installed with sudo apt-get install netcat-tradi...
by mjtrac
Sun May 19, 2013 4:00 am
Forum: Camera board
Topic: Frame rate issue after file transfer
Replies: 2
Views: 1218

Frame rate issue after file transfer

I've got my camera (yay! thanks!) and it works like a charm. When I recorded a ten second test video to filename "video.h264" it played back like a charm on the pi using omxplayer. However, when I transferred the recording to an Ubuntu laptop and try playing it back using avplay, it rushes by at a h...
by mjtrac
Thu May 02, 2013 4:58 pm
Forum: Camera board
Topic: STICKY: Foundation (old) Camera Board information
Replies: 443
Views: 279046

Re: Foundation Camera Board information

I'm very grateful for all the work everyone involved has been putting into the pi and especially the camera board. I agree that no promise was made of April. About a week ago, I got email from Element 14 inviting me to express interest in the camera board, indicating they'd let those of us who expre...
by mjtrac
Thu Apr 11, 2013 7:17 pm
Forum: Camera board
Topic: OpenGL Convolution on the GPU
Replies: 0
Views: 1467

OpenGL Convolution on the GPU

Hi, I'm hoping this is a reasonable place to post my possibly dumb, certainly obscure questions. I'd like to do edge detection on either camera input or non-camera images. First, can the open source drivers for the GPU handle OpenGL's 1D and 2D convolution operations? If so, does anyone know if the ...
by mjtrac
Wed Feb 06, 2013 5:06 pm
Forum: Camera board
Topic: STICKY: Foundation (old) Camera Board information
Replies: 443
Views: 279046

Re: Foundation Camera Board information

When used in snapshot mode, do you get the full 5 MP?

Is there a refresh delay, or can you theoretically take snapshots at multiple frames per second (ignoring any need to store or transmit them)?

Thanks.
by mjtrac
Wed Aug 22, 2012 4:58 pm
Forum: Camera board
Topic: some camera spec questions
Replies: 4
Views: 1914

Re: some camera spec questions

[quote] Geometry and vignette can be compensated for in software if that's an issue for your application. Python/PIL/Numpy can make short work of that with a little careful testing. Sure, maybe there may be some work to do to make this ideal for your application, but it's not rocket science either. ...
by mjtrac
Wed Aug 22, 2012 3:43 pm
Forum: Camera board
Topic: some camera spec questions
Replies: 4
Views: 1914

some camera spec questions

My hope is that the camera module, mounted to a skeletal cube along with some LEDs, will be usable as a way of quickly "scanning" 8.5 x 11 or similarly-sized documents. With that in mind, does anyone have information about any of the following? Thanks in advance. First, can the camera and lens fill ...
by mjtrac
Thu Aug 02, 2012 4:25 pm
Forum: General discussion
Topic: Dealing with the Memory Limit
Replies: 1
Views: 678

Dealing with the Memory Limit

Dumb question, I'm afraid, but I suppose somebody has to ask it? The 512 MB of addressability offered by the Pi is a mere 800 times what was considered the most that would ever be needed on a PC about thirty years ago. So it makes things a bit tight. I'm wondering what software engineering changes m...
by mjtrac
Fri Jun 15, 2012 9:40 pm
Forum: Camera board
Topic: Timeline?
Replies: 3
Views: 3513

Re: Timeline?

Thanks, Gert and Liz, for the reply as well as for everything else!

My Pi comes in late June. Can't wait.
by mjtrac
Tue Jun 12, 2012 3:20 pm
Forum: Camera board
Topic: Timeline?
Replies: 3
Views: 3513

Timeline?

I'm just wondering if anyone in the know would care to give an estimate of when the CSI module might be sent to a production outfit and/or become commercially available? As in, late this year, first quarter of next year, etc...

Thanks.
by mjtrac
Tue Feb 07, 2012 4:56 pm
Forum: Other projects
Topic: Create simple vector library
Replies: 22
Views: 7012

Re: Create simple vector library

<t>JamesH said: <br/> <br/> <br/> I was wondering whether to go synchronous or asynchronous. Async allows the Arm to get on with something else, but makes the whole thing a lot more awkward to implement with callbacks etc, and you have to be a lot more careful with protecting data from simultaneous ...

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