I have ruined cable of my current wired sensor three times. Do not ask me why..
And really like that simple wireless aproach of pro level 3d probes.
A lot of testing, making some test schematics - you need an special ir sensor for continous ir signal. And you need some sort of ir signal generator. Yes, guys are doing it (38khz) even using arduino... Others do suggest ne555.
Tried cmos 555 - ok, but it needs some good battery cr2032 gives 10 hours life time or very reducedworking radius.
But. Stumbled of one of app note - reduced frequency is used to tailor sensivity of ir signal to find correct distance to targed. So simplest chematic of joule thieft is able to deliver 38khz signal from single battery and four parts counts. More testing coming, yet till now all is nice and stable.
