The floating point registers are not currently used.  I think they're a hold-over from the initial design where I intended to add some simple math opcodes to allow scaling the raw results into a float.

One of my intended use-cases was to allow for visualizing the sensor values in the scopes plugin.  That only works when the value is in the right form.

I'll try to come extend the VM to use floats in a sensible way or I'll drop them from the register file.