I’m not Synthetos, so I can only provide advanced speculation based on hanging around here a lot. If you wander about Synthetos on gitHub, you will see some code for the Fin as well as as sub-project called Motate, which provides structured hardware modularity for various internals.
I’ll observe, with perhaps 80+% certainty, the Fin experiment was just that, a prototype. In addition to continued refinement and bug fixing for tinyG FW on the V7 and V8 ATXmega192 device; significant effort is being focused on porting tinyGfw forward to the more powerful ARM based uCs such as the SAM3X
My assumption, based on your interest in this topic, is that you want to build a tinyG based 3D printer or similar machine. You are not alone, several folks are actively developing controllers based on the tinyG2 framework. None are available yet, that I have seen. They wrap the tinyG motion control core with the additional hardware required for typical printer functions.
If you want to develop your own Application layer on top of established hardware (such as the V7 Fin), you might find that existing Shields combined with the Arduino DUE platform, which runs tinyG2 and has good FW build support, is a good understanding tool.
I have been working on merging a Ultimaker II Shield, mature and widely available at very reasonable cost, to the DUE Platform for CNC applications. But it does have some added control for the 3D application as well. Developed to run originally on an Arduino Mega, the Ultimaker shield is pin Compatible with the DUE, but one needs to be careful of the logic interface difference (5V vs 3.3V). I am still at it, but looks to be doable. There are other shields out there as well.
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