Thanks again for your latest reply.
I have now determined what I think are the correct calculations to perform with the raw numbers that come out of the sensor. Based on the Sensirion datasheets I think the sample code is for an SHT71 sensor rather than and SHT21. Modifying the calculations I can now get the same numbers as produced by the Sensirion GUI.
I afraid I do have another difficulty. I am working on a 64 bit system and want to create a 64 executable. The 'customized' library that Sensirion have given me is 32 bit.
The Code Mercenaries sample program does work to interface to our SHT21 (with the proviso that the calculations need adjusting). I suspect the library with this sample program isn't 'customized', but I could be wrong. This does look to be 32 bit though.
The dll distributed with the sample program seems to be different from the dll available from http://www.codemercs.com/337/?L=1
under the software tab. Maybe the latter is just 64 bit, re-compiled with another compiler etc.
I'll try and condense my questions:
If I was to take the Code Mercenaries dll source code and build a 64 bit library should the sample program work with it? Or is a suitable 64 bit dll available?
Are there any significant differences between the sample code's dll and the dll at http://www.codemercs.com/337/?L=1
Did Code Mercenaries create the 'customized' dll? Is the source code or a 64 bit dll available?