What would be best for this application? beagleboard? raspberry pi?

I suggest looking at the STMicroelectronics STM32F4DISCOVERY and STM32F3DISCOVERY boards.  They use ARM Cortex-M4 processors which have DSP instructions and the chips have analog I/Os.  If your application fits, it's a cheap way to go.  Both are available from element14, at least in USA.

Thanks for the reply john!

Just had a quick look at f4discovery and they really are quite cheap at approx £10 here in the uk. ( that does sound correct) which would be very suitable at i have a fairly low budget. Just a quick question, would this board be capable of attaching a webcam to for the camera system to take pictures and store them say approx 1 image per second? Id like them to be saved to an sd card if that would be possible for ease of use.

Thanks again

This sounds like quite the project!

I agree with John as well but I would personally use a BeagleBone or BeagleBoard. I have been playing with one and the python makes programming very easy. It is very fast and I think you will have very good luck with it. I believe anything in a single board computer format will work just fine for you, but it is basically how much data you really need to process. To take a picture is simple and store it. A BeagleBone is a very good tool but like you stated, if you want horsepower, get the BeagleBoard! They are so easy to use and it seems like everything was made so well!

You can use something like the following setup as an example:

LI-LBCM3M1 camera from Leopard Imaging, a module specially designed to work with BeagleBoard.

The module main features are :

• CMOS Sensor MT9T111 from Aptina
• 2048 x 1536 (3M) pixels resolution
• Output Data Format: YUV ( YCbCr)
• Focal Length: f=3.78+ /-0.1 mm, F2.8+ /-5%
• Vertical View Angle : 61.40
• Focus Distance : 120cm +/-2cm
• Focus Range : 60cm to Infinity

The advantage of using this kind of cameras compared to a USB Web-cam is the speed:

The Camera module from LI is directly connected to the Camera Image Signal Processing (ISP) interface on DM3730 (Beagle Board CPU) and thus, data from camera module can be processed much  faster than an USB camera.

The other good news is that this camera is supported in the Angstrom Linux Kernel, however only in the 2.6.32 version. The camera patches can be found here.

To enable the camera support you need an U-Boot  that contains I2C lines initialisation pull-ups (I’m using u-boot version 2011.09-r4)  and include the camera name in the U-Boot environment variables (uEnv.txt) :

For the kernel (omap-psp-2.6.32) make sure that the mt9t112 driver module is enabled :

Device Drivers ->

Mutimedia support ->

Video capture adapters ->

Encoders/decoders and other helper chips ->

<M> mt9t112 support

If everything went ok you should see something like that in your kernel traces (dmesg):

mt9t112 2-003c: mt9t111 chip ID 2680

and the  /dev/video0 node should also be  available.

To get some infos about the camera:

To take the first pictures, I used MPlayer:

To record a video using Mencoder:

Then you would need code to process the pictures either on the device or when you plug the SD card into your computer at home, office, school. As far as the hydrophone and accelerometer, these are very easy to come by and plug in, but it will take some programming to back all of the data at whatever frequency you prefer.

I guess in conclusion, I would try to use the smallest device with the most horsepower for the buck, but I am not sure of your application limits. It seems that most of the available single board computers will be able to the required processing for your needs. If you wanted one picture a second then I would highly suggest spending more money on a High Capacity Fast SD card so you won't miss any pictures, and to keep the processor cooler.

I didnt expect such a detailed responsed johnsocm, but thanks alot, it has given me alot to think about.

Basically i need to weigh up the pros and cons of each route that i would be able to take, then justify the reasons why i have taken the route which i end up choosing. I have only been given a budget of approximately £100, however items such as the hydrophone will be provided due to cost!

I dont really require much processing power as like i said, ill just need to take some snaps a few per second and really just wanted some idea as to which would be the simplest and easiest way to go about it. the aim of the project is to create an underwater system capable of capturing video, measuring acoutics and particle velocity to help understand the effects that underwater piling has on fish. so when the piling starts you can see how the fish behave.

Would something like this work?

BeagleBone - £60

32GB Mini SD - £12

LI-LBCM3M1 camera - £26.40 (Is this compatiable with both the beaglebone and beagleboard?)

accceleromemter - these are generally quite cheap

hydrophone - provided

underwater housing - will be made in house

i dont have a high level of programming experience, but how hard would it be to make the hydrophone and accelerometer system connect to the board and record data?

Sorry i think i got a bit carried away with this overly long reply

What I would suggest is buy a BeagleBone and play with the examples. I feel you can do this project with just the Beaglebone and not the board. There is enough I/O's and processing power to do your design.

The Beaglebone makes programming very easy and with the example I showed above you can setup the beaglebone and camera and take a picture or movie and not even know how to program. You can just modify the program and do what you want but python makes programming very easy! And partnered with the easy to use beaglebone would be a great start!

That sound very viable,  I may order one this week as I have had some experience with python.

Sorry i think im just missing something but you just said i can do the project with just the beaglebone and not the board? did you mean the camera board?

thanks again

Hi Yasin, if you would like continue to post your design progress on this site as a BLOG then I would be happy to send you a BeagleBoneBeagleBone to use in your design.

send me a private message.

Regards,

Shawn

yasin sheikh wrote:

 

Just had a quick look at f4discovery and they really are quite cheap at approx £10 here in the uk. ( that does sound correct) which would be very suitable at i have a fairly low budget. Just a quick question, would this board be capable of attaching a webcam to for the camera system to take pictures and store them say approx 1 image per second? Id like them to be saved to an sd card if that would be possible for ease of use.

Here's my guess: I think the STM32F4DISCOVERY has the hardware interfaces needed for a USB webcam and for an SD card, though you'd have to wire up a socket.  OTOH, I don't know whether the software you'd need for those interfaces is readily available.  Bare metal programming is really easy on a Discovery board.  However, a lot of people would rather just run Linux so they can use Linux device drivers and not deal with the bare metal.  When you run Linux you generally need to accept a truckload of stuff you don't need and a general-purpose Linux won't fit in 1MB Flash plus 192KB RAM.  Now a proper Linux hacker will tell you that you can build your own kernel and fit Linux into a tiny footprint, but I get the impression that the learning curve for that is more painful (JMO/YMMV) than bare metal programming.  Like all engineering problems, you have a trade-off.

Shawn's offer of a BeagleBone is very attractive.  It's a really powerful board.  According to my read of the TI AM3359 TRM, it doesn't have a DSP per se.  I don't know how much DSP your application needs.  OTOH, you can probably use the AM3359 Programmable Real-time Unit Subsystems (PRUSS) for some DSP operations using their MAC hardware.  PRUSS looks like a lot of fun.

I have accepted Shawn’s offer of the beaglebone, I think I will take it from there as it should be capable of meeting some of the requirements needed for the project. I think I’ll start by getting to grips with the board (complete novice), before moving on to the camera system first, and upon receiving the specs for the hydrophone, try and included that within the system as well.

I don’t think i will need a lot of DSP to be honest, as long as I can record the data easily from say an accelerometer and hydrophone, and integrate that with the camera function I should be okay.

In addition to using a beaglebone I strongly suggest that you get a suitable camera that has a very fast lens. This is to ensure that your pictures do not have the fish end up as just coloured smudges on a murky backdrop. Depending upon the depth you may also need to provide suitable lighting. As for sensing the fish you will probably need a sonar just like those used for fish finders as this can measure range.

Another question to ask is whether the electronics need to be at depth. Depending upon the application the electronics aside from the camera and sensor could be floating on the surface of the water and even be solar charged.

If you want this hermetically sealed without any penetrations (i.e. holes) you could use the TI QI power solution to provide power and act as a messaging conduit.