I want to use RS232 to control this "thingy", but it is going up/down with RS485.
Then you are not using 232, RS-232 specifies hardware stuff like voltage levels, slew rates etc. It has NOTHING to so with the format of the data. RS-485 is the same, it only specs hardware stuff.
So as I understand it you want to use RS-485 to talk async serial to the "thingy".
So, my question is, what boards do I need to get Arduino to talk with RS232/TTL?
Assuming my last comment is correct, you need a TTL->RS485 converter. There may be a board that does this but there are certainly a sh1t load of chips that do. So all you really need is a chip and a resistor at each end of the wire. The chips will output 5v async serial that you feed into the Tx and Rx pins of the respective Arduinos.
Do I need a "motor board" to control DC motors?
You will need something. You can roll your own motor controller but in this case there are several Arduino sheilds that can do this.
I want to dim the LED`s, can this be done with a simple I/O board with Arduino?
You can to this by driving the LEDs from the Arduino (often via a high-current driver chip or transistors, depends on the LED and the brightness you want). Once again there are shields that do this.
I also need feedback from the servos (position)
If you are controlling the servos you should know where that are at.
and a gyro
Plenty of breakout boards for these, probably look at sparkfun.com
and if possible from the motors also
Not sure what you mean there.
So in a nutshell, you can probably find shields to do all the above functions, but you may have trouble getting them all to work together as the Arduino backplane doesn't have shield addressing and often shield X uses the same pins as shield Y.
Have a look as shieldlist.org for a good collectio of available shields.
There may be a single shield that does all this, but i doubt it. So another option is to make your own if you have the hardware experience.
Rob
