Arduino Mega and Rainbowuino v2.0

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

I am attempting to program a Rainbowuino v2.0 with an Arduino Mega.

I have connected up the tx-tx and rx-rx and other wires as specified, but I am having no luck getting it to work.

The error I get from the Arduino IDE is as follows;

avrdude: Expected signature for ATMEGA328P is 1E 95 0F
Double check chip, or use -F to override this check.

Any ideas? This is driving me insane.

Thanks,
Daniel.

2

: Expected signature for ATMEGA328P is 1E 95 0F

Isn't arduino mega a 1280 chip? maybe you should check your board type settings in the uploader program.

Edit:

Sorry, I have misunderstood your problem.

3

I am able to program the Arduino Mega fine.

It is when I connect the Rainbowuino up to the Arduino and change the GUI board to MEGA328 that it fails to upload to the actual Rainbowuino.

I am not sure why it is failing.

4

I managed to solve the problem.

The Arduino Mega auto resets when the serial port is connected. Since this occurs whenever the PC establishes a connection, the Mega was resetting when attempting to upload the code to the Rainbowuino. This in turn causes the Mega to go into programming mode and the Rainbowuino is not seen.

To overcome this, you need to place a 47 ohm resistor between 3.3v and reset on the Arduino Mega board. This will prevent the Mega from resetting when you attempt to upload to the Rainbowuino. The upload via the Arduino GUI will now work and you will be extremely happy.

I hope this helps others.

Cheers,
Dan.