Issues with TTL-RS232 converters used with Altair-Duino 680

[Joseph Travis]

I'm curious if anyone else has experience any issues using the TTL-RS232 converters that are used with the Altair-Duino 680?

When connected directly to my laptop or using a real terminal, I get spurious characters that appear to be coming from the 680.  Oddly, when I place a DB-25 LED signal monitor inline the problem goes away.

Thanks,

Joe

[Chris Davis]

I've never seen that and I've used a whole lot of these.

Just as a test, power it with 5v instead of 3.3v and see if that changes the behavior.  (The logic lines will still be 3.3v, so you won't damage the Arduino Due.)