Having spent the best part of £2000 quid on this project sure whats another $400 for Mach4 and a decent USB controller??
If you think DDCSV is a bit of a minefield of poor user manuals and incomplete/undocumented code then I suggest you investigate using a MACH 4 controller and its mandatory Motion Controller and recommended break-out-boards.
There is no way that MACH 4, Motion Controller and a BoB will give you a turnkey CNC machine.
Its a nightmare of options.
Consider the system as implementeded:
The end to end functionality (i.e. G-Code to end mill movement) of your machine is controlled by two separate pieces of hardware and a PC. Two software programs are running (Mach 4 on a PC) and some FPGA code on the motion controller.
So who is responsible when a "feature" doesn't work. Reading the Forums it soon becomes clear that to fully understand MACH 4 and its controller you need to understand LUA (its macro/scripting language) and the underlying data structures (MACh4Core) that define your machine and Mach4.
Then you can implement your own M Codes!
You will need to know about things like these:
mcMotionGetAbsPosFract
mcMotionGetBacklashAbs
mcMotionGetBacklashInc
mcMotionGetIncPos
So to date I am not giving up on DDCSV!!