Bart started Flukso in 2007. It went to several iterations and by now it’s a CE-certified device that measures electricity, gas, water, and sends the data over 868MHz to a hub for collection.
The FluksoCube is an experiment that tries to pass the wife acceptance factor: rather than a board with a uprocessor and sensor inputs, it’s something that can be enclosed in a 3D-printable enclosure and still has sensor inputs. It has a ring magnet to make it easy to hook up and holds the frame together by attaching to the cell battery – to dismount it there is a hole in the back. The enclosure was designed in OpenSCAD, which means that the design is basically programming and supports parameters and stuff. The CAD file will soon be in github.
Inside there are two boards. the top board has a PIR, ambient light sensor, temp sensor, humidity sensor, barometer and accelerometer – most of them on a single I2C bus. It has a Cortex M0+ (LPCxxx). This processor has a pinmux so the external pins are fully controllable by software to be UART or whatever interface you need. The second board is the radio with the battery.
There’s a third board for debugging (JTAG, serial, firmware upload).
The Fluksometer itself has a new radio board now which uses the jeenode protocol, so it can pair with IoT sensors. [Here I lost a piece.]
Regarding battery lifetime, the radio is the most important part: the cortex can go to sleep aggressively and is woken up by sensor interrupts, the sensors themselves don’t consume much. To make the radio efficient, it is important to not send out data too often but also to reduce the number of bits that are sent out. jeenode does a very good job at that.