Dear Mr. Maurizio Crescini,

Check out the CMOS 4067 integrated circuit. It's features 16 analog inputs multiplex to one analog output.

I have used it in a device I built which reads 16 devices with outputs of 0 - 5 VDC. I multiplex their inputs one at a time and read it using a simple software analog to digital routine.

The results then are uploaded using a dial up arrangement to a desktop computer which then preps the data and sends it to a web site.

Regards,

Charles Bannister