[time-nuts] TruePosition GPS Receiver
kd5byb at gmail.com
Tue May 9 20:03:57 EDT 2017
Got brave and decided to experiment...and answered my own question below...
On 5/9/2017 6:02 PM, Ben Hall wrote:
> Does this mean that pins 7 and 8 are a TTL serial RX/TX pair that
> function the same as J2...but without going thru the Sipex TTL-to-RS232
> converter? That would be a score for those of us who want to use these
> things with Arduinos.
And the answer is sort of.
What I didn't understand in the original message is that "pins 7 and 8
are 3.3V TTL level" meant that pins 7 and 8 are connected together.
Pin 7 and 8 are connected together...and are TTL serial out.
Pin 3 and 4 are connected together...and are TTL serial in.
My little TTL-to-serial adapter is wired RX to pin 7, ground to pin 5,
TX to pin 3.
There is a catch! If you've got the jumper on J2 from using a real
RS-232 port...the TTL serial input won't accept commands. You've got to
remove the jumper.
This makes me happy - those of us who want to use Arduinos now don't
need to mess with going TTL to RS232 serial...can go direct TTL to TTL.
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