Hi everyone This was the other sensor project that I came across, using multiple arduino sensors to monitor humidity/temperature, collecting them with a RF receiver (though I wouldn't use xively.com to collect the data): https://computers.tutsplus.com/tutorials/building-a-wireless-sensor-network-... Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/