define(`TITLE', `2-Wire Lightsensor with MBus-interface (bus-powered)') define(`DATE', `2014-10-04') define(`CONTENT', ` Today it was a 2-wire (so: bus-powered) light sensor with MBus-interface: IMG_2378 Here, it is already mounted on the sill outside the window with a piece of double-faced adhesive tape, enclosed in the package of an Apple Magic Mouse. Note the piece in the lower-right corner (not the 10k resistor, next to it). This is finally the light sensor. It is regular BC177 transistor in metal case with the cap removed with a small Proxxon cutting-off machine. Works perfectly. The whole thing consumes about 500uA (the jumper in the top-middle is in the power line between the bus-transceiver and the rest of the circuit, just to measure the current). scan_006048 BTW, this is my first MSP430 project. It is much more "low-power" than the AVRs on the Arduino boards ... One note on the inhouse-wiring: The MBus-master is in the basement, the light sensor on the second floor. How to bring the MBus upstairs? Just use the already available infrastructure (Ethernet) cabling, which goes up from the patch panel in the basement into every room. Here are the sources: MBusLightSensor-2014-10-05 ')