Running Arduinos in Parallel

Hello again!

I was wondering if anyone has managed to get multiple arduinos running off the same serial port? My idea is to use a single USB to serial cable to broadcast the same data to 16 arduinos. I'm guessing I'd need some sort of buffer or line driver to make the signal stretch that far...

Any thoughts?



Might be a lot easier to send the data to 1 Arduino and link the remaining 15 to that one over I2C.

You could do a serial broadcast, so long as the arduino's never bark back anything (it would be like dialing a number and having everyone in the city pick up and say Hello...)

I agree with Mike though - having one do a Serial->I2C conversion is probably a better way to go.

The feasibility of I2C depends, in large part, on how far apart the Arduinos are going to be from one another: the I2C bus is not designed for long runs over cables. Plus, since this is going to be part of your 256-motor project, it could turn out to be an electrically-noisy environment.

My inclination would be to put an RS-422 or RS-485 transceiver on the motor interface board you're going to be building: it's cheap, simple, designed for multi-dropping, and very noise-immune. And could well pay for itself in reduced debugging time.

If you use something like a 75176, you can easily add the ability to talk back over the same twisted pair if you want it later.