[chsims1]

Thanks for the reply IanD, now I really should have been able to manage that one by myself.  For some reason, I had it in my head that the WD software downloads had all the extra drivers already included in them.

Edit: downloaded the only SHT1x library I could see, but that didn't sort the problem .... that library supplies 'SHT1x-ESP.h' not 'SHT1x.h.'