Zihatec Launches the M-Bus FeatherWing, Offers a Meter Reading Demo Sketch

German electronics specialist Zihatec has launched the M-Bus FeatherWing, designed to give Feather-format microcontroller boards the ability to monitor data from smart meters — and coming with sample source code for reading electricity meters.

"With this FeatherWing you can expand the well-known Feather microcontroller boards from Adafruit, Sparkfun etc. with functions for smart metering," the company writes of its creation. "The M-BUS FeatherWing can be plugged onto a Feather microcontroller board to read consumption meters with a so-called P1 customer interface (e.g. electricity meters in Austria). You can also use the FeatherWing to create your own meters for the M-BUS (e.g. to provide self-recorded data for an M-BUS [host])."

The compact add-on board, designed to maintain the overall footprint of a Feather-format microcontroller development board, is built around the Texas Instruments TSS721 M-Bus transceiver, and includes an isolated interface with screw terminals to one end. The device can work in two ways: it can read data from a compatible M-Bus meter, tracking everything from electricity and gas usage to water flow rates; and it can act as a meter of its own, feeding data into a separate M-Bus monitoring host.

To get users started, Zihatec has published a sample Arduino sketch which turns a Feather and the M-Bus FeatherWing into a reader for DLMS COSEM-based electricity meters, pulling in data including voltage levels, power factor correction (PFC) value, and active energy usage — though it will require, its creator notes, a decryption key from the meter's supplier in order to access the data.

The M-Bus FeatherWing is now available on the Zihatec website, priced at €24.99 (around $26); the sample source code is on GitHub under the reciprocal GNU Lesser General Public License 2.1.