btw, Pro 1 and Pro2 will be communicating over RS-232 via a MAX232 RS-232 Level converter.
So, with that said, it shouldn't matter either way.
You could deal with that using two resistors or a TXB0102 chip.
It has two VCC pins, VCCA and VCCB, connect VCCB to 5v and VCCA to 3v3 then run your signals through the data pins.The data sheet is quite clear I think.______Rob
Pullup or Pulldown Resistors on I/O LinesThe TXB0102 is designed to drive capacitive loads of up to 70 pF. The output drivers of the TXB0102 have lowdc drive strength. If pullup or pulldown resistors are connected externally to the data I/Os, their values must bekept higher than 50 k? to ensure that they do not contend with the output drivers of the TXB0102.For the same reason, the TXB0102 should not be used in applications such as I2C or 1-Wire where anopen-drain driver is connected on the bidirectional data I/O. For these applications, use a device from the TITXS01xx series of level translators.
And the OE pin should be tied to Vcca, correct?