RS485 Interface Extension

摘要

The central heating meter described elsewhere in this issue is a clever device that can help you keep on top of your fuel bills by measuring the number of kilowatt-hours actually delivered by the heating system. As described in the article, it does this using just four temperature sensors attached to the central heating pipework. The signal from the sensors is conditioned by an analogue circuit and then digitised using an A/D converter in a microcontroller; PC-based software then does the necessary calculations and provides a display of the instantaneous system heat output .