Choosing the right MCU for my project

Hello,
I want to start a new project for my camera remote control, but i don't know what mcu to choose.
I'm also thinking that this mcu has to be easy to program and offer aces to a forum
In the Block Diagram picture the sensors will be connected to the TR1 by wire.
TR1 will transform the analog signal (0-5V) in digital and send it to the central unit,
TR1 will also control the sensors power (On/Off).

The central unit will receive signals from TR1, process these signals and then send the
signal to the TR2 (the wireless interface between cental unit and camera). The central
unit can also receive data via TR2 (thumbnails, camera parameters) and display on a OLED
screen.

In wired mode the sensors will be connected directly to the central unit (analog data)
and via USB with the camera.

Now i'm thinking to a combined mode:

  1. Central unit <-> sensors wireless + Central unit <-> camera via USB;
  2. Central unit <-> sensors analog connection + Central unit <-> wireless;

So the central unit MCU must handle data transmition, data processing and
screen control.

I would say you need a Mega because of the multiple serial ports.
However make sure the USB requirement is nailed down, the Arduino can not easily be a USB master.

Will Mega 2560 or ATmega1280 at 16MHz will handle thumbnails transfer from camera to lcd in lets say 2 seconds?

Whoa, how are you going to transfer image data. That is a whole different ball game.
What exactly are these T1 and T2 devices?

Are the images compressed? Do you know the format?
How are they getting out from your camera? Is that the USB bit?
How are they getting into the LCD? Is the LCD connected to the arduino? If so what is the interface?

TS1 and TS2 are transmit/receive data wireless modules, they will enable the link between sensors, central unit and camera.

I don't know yet. JPG
Through USB using PTP protocol
They are transferred via wireless or usb into central unit thant can be an arduino or similar board with more power and the interface will be SPI or ...something else

The LCD can be something like this MI0283QT Adapter v2 (incl. 2.8" LCD + Touchpanel) - Watterott electro
and the board can be http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,892,894&Prod=CHIPKIT-MAX32

I don't know yet. JPG

You can't decode JPEG with an arduino, there is not enough processing power or memory space.
As I said the arduino can't handle USB transfers from a camera.

interface will be SPI or ...something else

Until you tie down the specification there is not much point in looking for an implementation. However it does look like what you want to do is outside the comfort zone of an arduino.

Hello Mike,
Last night, using Canon SDK i did some testing using a small vb program and the camera is lagging too much on usb,
it is way faster on remote control port (remote triggering by sensors is will produce only junk images).
So, I'm guessing that image transfer and usb connection is out of discussion,
all that remains is the wireless mode and maybe a bigger screen.

All i have to do is add wifi to this project http://grozeaion.com/electronics/high-speed-photography/125-gvi-dslr-rc-with-touch-shield-slide.html