Hi, Didn't make it clear but that's what I did in step (E). (E) should have read: 'Go back to code before any messing about with serial port and try pins P1.0 - P1.7, all devices detected but only POR value returned.'

Software brain has assumed it's the (my) code, or my misunderstanding of something in the bits of code grabbed from the examples and the web. Also have cross compared the code with code from other projects on the web and can't see particular differences in what is happening, most notable difference is that other projects use pins in P0 and P2, which I can't because there is external RAM on them.

I've tried another of the same type of experiment board to make sure it's not something obvious like a faulty board or processor, and checked that all P1.0 - P1.7 work at the basic level with switches and LEDs.

The fact that no matter which pin is used the devices are always correctly detected and that a sensible value (either the POR for the specific device, 0x0550/0x00AA, or proper converted temperature) is always read suggests to me that at least the interogating of the devices works, leaving the possibility that there is and issue with sending the command to the devices to cause temperature conversion.

It's been about 2 weeks of a couple of hours a day trying to get this to work, and still fully prepared for the problem being one of my own making so suggest the most basic things, unless they need an oscilloscope :)

Thanks, Luke