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FTDI Cable and ATMega328

Discussions on the software and hardware for Atmel's STK standard.

FTDI Cable and ATMega328

By TheRealChaz
-  Wed May 04, 2011 9:43 am #126534
I just got an FTDI cable, and I'm trying to use it to communicate with an ATMega328.

The TXD line on the cable is always high. It looks like it blinks a bit when I try to send data. It's as if the signal is inverted (normally high, temporarily low when sending a bit). Does this sound correct?

Thanks,

Chaz

Re: FTDI Cable and ATMega328

By rrpilot
-  Wed May 04, 2011 11:10 am #126537
TheRealChaz wrote:The TXD line on the cable is always high. It looks like it blinks a bit when I try to send data. It's as if the signal is inverted (normally high, temporarily low when sending a bit). Does this sound correct?
The serial line idles in the high state, so yes that sounds correct. A start bit is detected with a high-to-low transition. You may want to do some wikipedia reading on UART's.
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