4. Energy Sensors

This section is dedicated to reading energy sensors either on your central heating system or anywhere in the house.

4.1 Reading a SMART meter

By the year 2018, all Dutch homes will have a "smart" meter for electricity and heating with natural gas. The so-called P1 port on the electricity meter offers access to the electricity and gas consumption over its serial line interface. The P1 port is accessible by home owners and allows them to read power usage and natural gas usage on a permanent basis.

The P1 port is a small RJ-11 port on the electricity meter of your house. Most of the time, the Natural Gas meter is also digital (or SMART) but it is connected to the electricity meter through a small cable. This is because the utility company can access such a small computer in the meter through the electricity network (and not though the gas distribution system obviously).

SO what do you need:

1. A connecting cable from your smart meter (RJ-11) going to a distribution network in you houase (RJ-45 based) or directly connecting to ...
2. Conversion from RJ-11 or RJ-45 (see previous point) to a serial RS-232 9-point interface
3. Convertor from RS-232 to USB on the Raspberry.

Strange enough there does not seems to be a direct converter from RJ-11 to USB, and therefore an intermediate step with the 9-pin RS-232 connector is needed.

4.2 Reading the temperature of your central heating system

*** This section is identical to the temperature sensor section in the weather section in chapter 2 and 3