At 06:51 AM 4/15/2014, KPL wrote: >It was not THAT huge issue, I tried both pull up and down with a 10K >resistor, but got different reaction upon connecting of different >usb-serial, that's why i asked for better options. Currently it's left >with pull-up, which seemed more logical. A pull-up resistor is the proper way if its a TTL-level signal. If=20 you have having noise pickup issues, reduce the value of the pull-up=20 resistor. 1k is about as low as you should go, though. dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .