Colin McGuire

HCS12C32 SCI inferface with GPS Module

Discussion created by Colin McGuire on Feb 11, 2009
Latest reply on Feb 12, 2009 by Carl Barnes

I am interfacing with a GPS module which requires a LVTTL, 4800 baud, no parity, one stop bit signal.

LVTTL level is 0-3.5V. I have two questions:

First, do I need to boost this voltage range to 0-5V to interface.

A problem I have is that when I connect the Tx of the GPS module to the SCI Rx on the C32, the output jumps from pulses between 0-3.5V to a steady 4V with the pulses with a peak to peak of about 400mV on top of this. Do I need some sort of circuitry to correct this?