Accidently revisited this thread and saw thats its still alive.
mwahlgreen:
but the author (as always on a forum) never gives the thumps up for what he/she did, that actually works.
I put it in the too hard basket and delayed the project, but I am now looking to revive it.
I have done a lot of Googling since and am leaning towards a simple op-amp/transistor setup. Like the diagram below, but using an analogue pin and smoothing cap instead of the zenner to provide the input voltage.
I will prototype it in the coming days and will make up my mind then.
