RGB matrix questions

g'day, i just got my Arduino mega 2560, 2 rainbowduinos and 2 8x8 RGB LED matrix's for use on the rainbowduinos, i have a couple of burning questions before i start using the matrixes:

  1. ive heard you shouldnt power the V2 version of the Rainbowduino AND the RGB matrix off the arduino board, is this correct?
  2. im looking at getting a constant powersource for the boards and the RGB matrix and i would like to know how many amps i should go for on the power supply so i do not fry anything

cheers, kin.

(i apologise if ive posted in the wrong forum section)

would like to know how many amps i should go for on the power supply so i do not fry anything

You can't fry anything by connecting up a power supply capable of supplying more current than you need.
http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html

cool, ive settled for a 2.5Amp power supply, though now ive run into another problem with my Arduino Mega 2560 and my Rainbowduino, i hooked up the Rainbowduino via RX, TX and reset, and ive uploaded a blank sketch onto my mega 2560, swapped the board type to ATmega328 and tried to upload to the rainbowduino, alot of stuff doesnt compile properly and thorw back errors but anything that does work i try to upload, it then says upload complete but gives me this error:
"avrdude stk500_getsync(): not in sync: resp=0x00"

and as a result nothing i upload to the rainbowduino works, how can i resolve this, or am i using the wrong arduino board?

Assuming the power and ground are common between your arduino and the rainbowduino have you got a boot loader in the rainbowduino. I have come across a few people who have problems uploading to it. Does the original rainbowduino sketch still work?

i do not know if i have a bootloader on the rainbowduino, however, when i turn on the rainbowduino, it displays the default pattern standard on all rainbowduinos, even when i upload to it and it says it's completed, it just stays standard pattern

the message:-
"avrdude stk500_getsync(): not in sync: resp=0x00"
means it has not communicated at all with the processor. This can be due to lack of boot loader, not resetting at the right time or no communications either no connection or wrong speed.

do all rainbowduino's been to be burnt with a bootloader from the factory? ive reset it at the right time and got to upload with the stk500_getsync error, and the communications speed is at default, i think it was 9600 in device manager

The communication speed used by the boot loader is set automatically independently of the communications speed set in the arduino API.

I don't know if the boot loader is fitted as standard on this system, I only know that a lot of people have had trouble doing what you are trying to do and I have not come across a satisfactory answer to this yet. Sorry.