On Mon, Feb 15, 2010 at 4:09 PM, Curt, WE7U <[email protected]> wrote:
> Have a spare serial port on the Atmel? A 'Y' cable coming from the > GPS is the best way to snoop. I suspect you're probably low on > ports though as you'll only have one or two. Maybe an 8-pin Atmel > or PIC to monitor the GPS line, then query it over SPI periodically? I was headed down that very road (plan was to bit-bang GPS RX, not worrying about the occasional lost sentence due to the CPU being busy), but I'm basically trying to avoid all of that. The ATmega8 series only has one UART, and that's tied to the T2's A port for the primary mission. All this GPS stuff is future code to be implemented, as I currently have too many irons in the fire anyway, but if it works this way I can go ahead and do a PCB, and add all the features in software without a PCB redesign. In addition to trying to keep it simple, I'm also trying to keep it small - something along the lines of an OT1+ case would be ideal, although that's a bit optimistic considering the number of connectors I need. I'm currently working the tradeoff between number of connectors and complexity of the cables. :| snoop looks perfect, but I wasn't sure if Scott had to make some compromises that would affect APRS monitor mode to make it happen. I don't know much about a "HASP" rig, but it appears to make a TNC+GPS on a HASP cable out of the T2 A port. snoop would need to be sticky to make that one real, though, as snoop seems to go off if I hit enter. -Jason kg4wsv
