[aprssig] aprstracker-0.11 configuration issue on linux

[Joe Kirby]

> My guess is that it is HW related. Just like most of the PIC based
> trackers, the serial data-out of the PIC in Foxtrak is directly
> connected to the serial data-in of the PC. The PIC operates with 0-5V
> signal levels while the RS-232 serial port of the PC probably expects at
> least -3V (minus) instead of 0V.
> 
> Most serial ports are very forgiving and accept the 0V as a defined
> level. But some don't in which case you should try another PC, or put a
> level converter in between.

That makes a lot of sense. I couldn't use a "direct" programmer with
this serial port.

While connected via minicom, I noticed the tracker would occasionally
become unresponsive after sent a '!' and then typed something else. I
added a usleep(1000000) between the leave_programming() and write() of
the enter_programming function. That seemed to clear the problem up at
the cost of making things slow to start. If I get a chance, I will
shorten that value and see when I start having issues again.

Thanks for your reply.

73 de K1RBY