SparkFun Forums

[mzoran]

I'm connecting a PIC chip to a lacross weatherstation that has a RS232 port. I know the serial in and serial out pins need to be passed though a RS232 level converter. The serial commincation requires that the DTR line be asserted at the start of the communication and deasserted at the end. Should I pass the DTR line though the level converter as well, or does that line use TTL levels?

[Philba]

yes, you should pass dtr through the level shifter. the max232 has 4 of them so it shouldn't be a problem.

you might get by with ttl levels but why take the chance?