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by kkjkearney
Thu Sep 22, 2016 8:39 pm
Forum: Python
Topic: Separating USB Input
Replies: 1
Views: 497

Separating USB Input

I'm using a Raspberry Pi 3 Model B. I'm running Jessie and programming with Python. I have two USB devices that give me data input. They act like keyboards, "typing" numbers and then sending a "carriage return". Problem is, I need to discern which device is sending which information. Is there any wa...
by kkjkearney
Fri May 20, 2016 4:22 pm
Forum: Camera board
Topic: Transitioning to the new camera
Replies: 2
Views: 677

Re: Transitioning to the new camera

Boy, the change in lens aspect between V1 and V2 sure confused matters. I was hoping for more resolution in the existing FoV, but it seems I've got effectively the same resolution, or maybe even less? Not sure. I'm finding that to get the same image results with the V2 camera, I have to crop the ima...
by kkjkearney
Fri May 20, 2016 2:54 pm
Forum: Camera board
Topic: STICKY: Foundation (old) Camera Board information
Replies: 446
Views: 302055

Re: Foundation Camera Board information

Maybe un-stick this, or at least describe it as the old camera board?
by kkjkearney
Fri May 20, 2016 2:52 pm
Forum: Camera board
Topic: Transitioning to the new camera
Replies: 2
Views: 677

Transitioning to the new camera

Love the new V2 camera, many thanks for your hard work. White balance is much better, but I'm trying to figure out how to make the use of the higher resolution in my microscope application. The PiCamera documentation (https://picamera.readthedocs.io/en/release-1.10/fov.html) did a great job of expla...
by kkjkearney
Fri Mar 25, 2016 5:40 pm
Forum: Raspbian
Topic: Inserting and removing USB Memory Stick
Replies: 2
Views: 795

Re: Inserting and removing USB Memory Stick

Excellent, nice and simple. Thank you Dougie. For amateurs like me, Pcmanfm is simply the default file manager that comes with Raspbian. Can someone help with my second question... Are there simple Python commands to dismount each time a picture is saved (assuming the user is going to pull the stick...
by kkjkearney
Fri Mar 25, 2016 2:07 pm
Forum: Raspbian
Topic: Inserting and removing USB Memory Stick
Replies: 2
Views: 795

Inserting and removing USB Memory Stick

Just began using Jessie, and am happy to see simple USB memory stick functionality without complex mounting, etc. First: In my application, the user will insert a memory stick, to write a captured photo to the stick. When the stick is inserted, a dialog box pops up asking the user what to do with th...
by kkjkearney
Wed Feb 03, 2016 3:09 pm
Forum: Camera board
Topic: PiCamera rolling shutter problem
Replies: 13
Views: 2719

Re: PiCamera rolling shutter problem

Through trial and error, I arrived at an acceptable exposure_speed of about 15,000. Multiples of any value made no difference. As I mentioned, fixing the exposure_speed takes away much of the camera's ability to adjust to changes in lighting. Is there a way to define a minimum value, and allow the c...
by kkjkearney
Tue Jan 26, 2016 5:36 pm
Forum: Camera board
Topic: PiCamera rolling shutter problem
Replies: 13
Views: 2719

Re: PiCamera rolling shutter problem

OK, making progress! I queried the camera settings with a "good" and "bad" light source. With the offending LED source: shutter_speed = 0 exposure_speed = 2895 Result: preview image looks like jelly With another (badly) offending halogen source: shutter_speed = 0 exposure_speed = 1470 Result: previe...
by kkjkearney
Tue Jan 26, 2016 4:01 pm
Forum: Camera board
Topic: PiCamera rolling shutter problem
Replies: 13
Views: 2719

Re: PiCamera rolling shutter problem

I've eliminated RF interference as the cause. With the offending light source turned on, I can block (and unblock) the offending light from hitting the camera while leaving the source running. The effect occurs only when the light hits the camera. If I block the light (but leave the source running),...
by kkjkearney
Mon Jan 25, 2016 10:13 pm
Forum: Camera board
Topic: PiCamera rolling shutter problem
Replies: 13
Views: 2719

Re: PiCamera rolling shutter problem

Here's a YouTube video that better shows the effect.
http://www.youtube.com/watch?v=hzrZuNwBYCo

Thanks for your help.
by kkjkearney
Mon Jan 25, 2016 8:43 pm
Forum: Camera board
Topic: PiCamera rolling shutter problem
Replies: 13
Views: 2719

Re: PiCamera rolling shutter problem

Thanks for the quick response. I should have said, I'm in the US (60 Hz) Here are YouTube links to a few 5 second videos showing the effect: LED Back light plus dimmable Halogen top light: http://www.youtube.com/watch?v=abvGcqWmxPQ [Halogen toplight only, non-dimmable: http://www.youtube.com/watch?v...
by kkjkearney
Mon Jan 25, 2016 4:49 pm
Forum: Camera board
Topic: PiCamera rolling shutter problem
Replies: 13
Views: 2719

PiCamera rolling shutter problem

I've built a microscope system based upon the PiCamera; it works very well. Problem is, when in preview mode, the rolling shutter reacts very badly with certain light sources (dimmable halogen and non-dimmable LED). Even though the image is stationary, I get a horrible swimming "jello" effect. I und...
by kkjkearney
Wed Dec 23, 2015 7:46 pm
Forum: Camera board
Topic: PiCamera - Variation between preview and capture
Replies: 1
Views: 530

Re: PiCamera - Variation between preview and capture

Mystery solved... The image went into my array as BGR, and I used it as if it were RGB. The subject under the microscope was not strikingly different colors, so it wasn't obvious that it was simply a color swap.
by kkjkearney
Wed Dec 23, 2015 3:39 pm
Forum: Camera board
Topic: PiCamera - Variation between preview and capture
Replies: 1
Views: 530

PiCamera - Variation between preview and capture

I've created a microscope application using a Raspberry Pi 2 and a Raspberry Pi camera board. I'm programming in Python using PyGame, cv2 and picamera 1.10. Works great, with one exception. Previewing to the screen looks great, with a very responsive image, good colors and excellent reaction to chan...

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