KurtE:
I am sorry if this has been answered before, but my searches are not showing up any thing...I would like to connect one of the USARTS of the DUE to an SSC-32 (servo driver board), whose TTL is at 5v.
What is the preferred way to connect them. I figure the TX is fine as the SSC-32 will probably handle the lower voltage just fine. But about the RX where the SSC-32 may return data.
Limiting Resistor? if so how big
Resister Divider?
Other?
If you are planning to connect to the DB9 connector you need to handle voltages -12 to +12. TX might possible work at 3.3V, but it is pretty borderline. I would use something like MAX3223 to provide proper translation levels.