Thanks for the tips. I've seen posts elsewhere hinting to the data layout and once I get reliable data value I'm confident I'll be able to crack the code. Right now however I'm trying to get a sensible bit stream. I get a steady stream of random 1 and 0 meaning I'm just seeing noise. I think I have to filter this (I didn't have, so don't fit the 1k resistor on the data line, but I'll try that next) then there are 4 further filter settings in the code: min, max, min long and max short, getting the right values for these seems to be the trick. I'm going for trial and error, but that's a lengthy process. But a challenge is good right?