Here’s my journey with installing AOG on a 2012 S670.
I started by reading these forum posts
Summary: We don’t know how to integrate via can bus so we must connect to the raw sensor/valve wires and some JD tractors have a variable duty encoder & some have a quadrature encoder. My S670 has the variable duty encoder.
I'm using an AiO Prototype to connect to the JD harness via the SSU connectors. This means unplugging the SSU (underneath the cab) which causes a warning in the 2630 display's diagnostics but it does not cause any issues. Then I plugged in the [30 Series SSU adapter created](https://discourse.agopengps.com/t/adapter-for-deere-ssu-replacement/20461) by @theGtknerd (with some modifications, he's since created a dedicated S Series adapter board) to the JD SSU connectors and ran a multiconductor wire into the cab to the AiO PCB.  
The adapter board is meant to be potted using this tray/box
I created a testing harness with two SSU adapter boards. This allowed me to sit in the cab while checking signals with a multimeter. I had to reconfigure the harness a few times until I found the correct pinout for my combine because it’s a hybrid between the 30 Series & R Series.
Here are my pinout modification notes. I was even able to find the corn header row sense signals on the SSU connectors!
To summarize:
It works awesome!
ps: I thought I had cab tablet mounting pics but I can't find them right now, maybe later.