Serial link between Arduinos

Hi --

is there a simple tutorial and software examples somewhere on how to link up two boards using a serial connection between them?

I need to send a value from one to the other, very simple.

Cheers Sascha

hi

if you poke around the forum you will find lots of posts on this. I know that several people have done it, using various techniques: RS232, RS-422 etc. For example there is an exhibition in Montreal right now by someone that uses 40 Modern Device "Barebones" Arduino-compatibles networked together, but they haven't postd how they did it yet.

Use Google to search the forum, as the forum search only goes back a few weeks for some reason.

One problem you will encounter is that during boot up the serial port(s) are used by the Arduino to check with the IDE.

D

Easiest way is to connect the TX to the RX and vice versa. Nothing else is needed. Just use the standard Serial stuff.

Easiest way is to connect the TX to the RX and vice versa.
Nothing else is needed. Just use the standard Serial stuff.

How does the power work? Do I connect one through USB and the other through a power adaptor? Or do they both run off a shared connection (if not, do they have to have a common ground?).

Which data type is best for exchanging values from 0 to 255, DEC?

Cheers,
Sascha

Easiest way is to connect the TX to the RX and vice versa. Nothing else is needed.

... except a ground.

-j

How does the power work? Do I connect one through USB and the other through a power adaptor? Or do they both run off a shared connection (if not, do they have to have a common ground?).

Which data type is best for exchanging values from 0 to 255, DEC?

You can make them share power by connecting 5v and GND together.

Use BYTE to send the values. DEC is for humans only. :)

One problem you will encounter is that during boot up the serial port(s) are used by the Arduino to check with the IDE.

D

Hmmm. How do you get around this?

...

One problem you will encounter is that during boot up the serial port(s) are used by the Arduino to check with the IDE.

D

Hmmm. How do you get around this?

Wait, here is an idea. You could have one Arduino power on the second Arduino using a TIP120 transistor.

So, first Arduino boots, doesn't see the IDE, starts the second Arduino. The first Arduino resolutely ignores any activity on the serial port until the second Arduino boots.

Also, once the code is sorted out, you could use AVRStudio to transfer the software without the bootloader.