[TriEmbed] Camera Advice

Tue Apr 29 21:52:28 CDT 2014

Ted, some of your issues are more related to photography than embedded computing.

The picture you sent is a perfect example of a backlit subject.

You are going to have to overexpose the sky and trees in order to get the bird properly exposed.

You are taking the picture through window glass at an angle, which gives you reflections.

You need to be happy with the images before you try to figure out how to automate their capture.

If I were doing this, I would be using my Nikon DSLR camera with a longer lens looking straight out through the window (or I might move it outside).

To trigger my camera, I would use an Arduino and an IR LED to simulate the remote trigger capabilities of the Nikon (just google: arduino nikon remote). 

There is a package called “motion” for Linux that will turn a webcam into a security camera, recording only when something changes in the scene.

This might give you nice clips of each visitor to the feeder.  I am sure that there are multiple packages that do similar things.

---> Paul

From: TriEmbed [mailto:triembed-bounces at triembed.org] On Behalf Of Carl Nobile
Sent: Tuesday, April 29, 2014 10:16 AM
To: Ted Pudlik; TriEmbed
Subject: Re: [TriEmbed] Camera Advice

Ted,

I took a look at that link you sent. It looks very interesting, but It will only make your situation more complicated if you want to use a microcontroller I would think. If you stick to a computer based system, which it looks like you will need to, it may off load some of the things you need to do onto pre-built functionality making your life a bit easier.

Carl

On Tue, Apr 29, 2014 at 9:59 AM, Ted Pudlik <tpudlik at gmail.com> wrote:

Hello,

It's too bad things are so complicated---thank you for clarifying it, though!  Another TriEmbedder suggested I use a Canon camera with CHDK ( <http://chdk.wikia.com/wiki/CHDK_in_Brief> http://chdk.wikia.com/wiki/CHDK_in_Brief) as an alternative to a microcontroller-based solution, as it gives access to functionality like motion detection and does all the "heavy lifting" of running the camera for you.  I'll definitely look into it some more.

Best wishes,

Ted

On Mon, Apr 28, 2014 at 2:31 PM, Carl Nobile <carl.nobile at gmail.com> wrote:

Hi Ted,

Cameras are complex devices and will almost certainly need a compatible driver for the camera. This is why they are always used with a full blow OS.

The only way that I know of to use a camera with a microcontroller is to process the raw data stream yourself. This is essentially writing your own driver and will most likely need more memory than what a microcontroller can offer. You may be able to see what you are dealing with by attaching the camera to the USB connector on your computer and look at the raw data coming from the USB. This is not generally doable without a scope and some skill with how USB ports work however.

Sorry, but as I said above cameras are complex devices and there is no easy way to deal with them.

Carl

On Mon, Apr 28, 2014 at 1:32 AM, Ted Pudlik <tpudlik at gmail.com> wrote:

Hello,

I'm working on a system for my bird feeder that would detect birds, take photos of them and put these photos up online.  I assembled a working prototype using a Raspberry Pi (with a WiFi dongle), a passive IR sensor and a Logitech webcam, but it suffers from two drawbacks:

1.	The power consumption of the Pi is too large to permit long-term operation on battery or solar power, restricting installation options.
2.	The image quality leaves a lot to be desired.  (Here's an example picture <https://www.dropbox.com/s/bdqquj6um0vluyg/Carolina_Chickadee.jpg> .)

To solve issue 1 while keeping WiFi connectivity easy, I'm looking into replacing the Pi with an electric imp <https://electricimp.com/> .  I'm not sure what to do about the camera, though.  Adafruit sells a camera accessible via serial port <https://www.adafruit.com/products/397>  that can be made to work with the imp <http://forums.electricimp.com/discussion/comment/5824#Comment_5824> , but capturing quality stills is not its strength.  The excellent built-in iPhone cameras can be bought surprisingly cheaply on eBay <http://www.ebay.com/itm/Replacement-Rear-Facing-Camera-for-iphone5s-/281316823054?pt=US_Other_Cell_Phone_Accessories&hash=item417fca100e> , but I'm not sure how to get them to talk to anything other than an iPhone.  Another possibility might be buying and cannibalizing a cheap digital camera <http://www.amazon.com/Kodak-Easyshare-Digital-Camera-Silver/dp/B003VTZE1M/ref=sr_1_2?ie=UTF8&qid=1398662318&sr=8-2&keywords=digital+camera> , but again I don't know if the modules inside could be interfaced with a standard microcontroller.

What would you recommend?  What's the best way to get a reasonably priced camera that takes high quality stills and can be easily controlled through a standard bus?

Thank you for your help!

Ted

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