A couple years ago I bought a bunch of cheap Chinese digital calipers with the notion of using them to build my own DRO (Digital Readout) for a mill or lathe, or getting one from ShumaTech which now seems quite defunct. A couple weeks ago I stumbled upon a newer project using an Android device as a DRO, with a simple Arduino hardware interface to some magnetic scales. The developer has since added support for the Texas Instruments MSP430 Launchpad board, and is in the process of adding support for the cheap Chinese scales and calipers. I’ll do a full write-up when I build the system. (I’ll be installing it on the lathe, since the mill will be converted to CNC in the near future.)
He was supposed to release an updated version of the firmware that supports the Chinese calipers the weekend this was originally posted, but it’s been two weeks now, and nothing. So I think I’m going to have to get back to writing my firmware now that I have my sample voltage shifter chips from TI.