westfw:
the ATtiny13 doesn't have a hardware serial port.
That is a good point. I haven't used (or looked into) the Tiny13A- I assumed it implemented USI or software serial in the same way as hardware serial.
Having said that, because the OP said this:
chriscuddihy:
I'm trying to send M commands to an ATtiny13A that has already been programmed...
What I want to do is send the commands from the Arduino Uno to the ATtiny either via the serial monitor or in the loop.
I assumed this thread was more about sending the serial from the Uno, rather than dealing with the ATTiny13A side of things.