ST7002 as control for PyPilot?

[burgoynebc@netscape.net]

I have opted for a SeaTalk1 instrument for the very simple reason that NMEA2000 or SeaTalkNG instruments are much more expensive and there are not much sold at all 2nd-hand. 
I am also not interested in expanding the system with more equipment, I just want to control my PyPilot with the ST7002 instrument.

I have made some more progress in the project: I can now read (in 8-bit, but it works and is stable) all button press commands from the SeaTalk-bus and can write the commands for the virtual course computer so that the ST7002 displays the correct data. I need to do some more fine-tuning in that (send commands using timers to lower the SeaTalk bus load, and write some conversion functions for course, heading and rudder angle). 
and after that I will start in including this code in the ‘motor.ino’ code so that it all runs on a single Arduino Mega.

There are two motor.ino sketches - Sean dePagner's original bit banging and an update available on hackaday - I think this one is an improvement. 
on autopilot controls watch out for 0 deg = 360 deg, and chaos created if cts and cog are in 3rd and 1st quadrant - you need math in sketch to correct for both. There is also a complicated math equation avail that does both that I found but have not understood.
I'm checking my install on new boat for how/if seatalk or 0183 networking is used. For Hdrive output from mega I am using IBT-2 modules 
If you want some more insight into openplotter best to make contact on my burgoynebc@netscape.net email
Richard
SV Kelaerin