[aprssig] D710 Greenlight Labs GPS and AVMAP?

[Stephen H. Smith]

On 6/21/2012 11:05 AM, Bob Bruninga wrote:
> I don't need input from the AVMAP since the Greenlight is always connected.
> I just want the output data (waypoints) to show on the AVMAP.  So is it true
> that the Greenlight does have a pass-through sub minim jack?
>
> Bob
>
>


But again, whether you use a 'Y"-cable of some sort, or the Greenlight's 
pass-through, you would be wiring two  RS-232 OUTPUTS (The AVmap's NMEA output 
and the Greenlights NMEA output) IN PARALLEL.

Even if there is some option to turn off the AVmaps output NMEA stream so it's 
receive-only for data sent FROM the Kenwood, you will have the output side of 
the AVmap serial port resting at  the negative 5-8 volts of a  quiescent RS-232 
circuit (or possibly at 0 volts if it uses 0/5 "half-232" inverted TTL output), 
in parallel with the active output of the Greenlight.

Unless of course, you want to hack cables and cut the TXD line of the cable 
from the AVmap, making it permanently receive-only.   (And this assumes the 
Greenlight "passthrough" actually passes in both directions -- it may only 
provide OUTPUT to supply NMEA data to a laptop in parallel with the D710. )