Talk:Microstepping with optical feedback
why are you sampling inputs during a timer interrupt when you could use interrupt-on-change or even the counter subsystem? - Triffid Hunter
Have you considered try this setup with a mouse optical sensor mounted on the carriage measuring the surface of the axis rod? the ADNS2051 sensor has quadrature pins (like most of these days optical mouse sensors) and should act just like the linear encoder. Would be interesting to compare that with the printer-hacked-linear encoder to check how much precision a mouse sensor could get!! ADNS2051 have a maximum of 800DPI, which should give a response of 31.75 microns per measurement. Later revisions can go up to 8000DPI, or 3.175 microns (which is just crazy!!) Hradec
Extending to a three phase system
This could be extended to drive three pphase brushless model aeroplane motors like we often find in quad copters.
It has 3 wires so could still use the same driver circuitry.
It has many fewer steps (poles) per revolution but this should not cause much difference.
Kalle -- Johannesburg, South Africa