Smartmetering with Portenta H7

Portenta H7

M-BUS MKR Shield

OpenMV IDE

Due to rising prices for oil, gas and heat as well as climate change, it is becoming more and more important to monitor energy consumption in order to keep an eye on energy costs, but also to be able to check the effectiveness of savings. Many meters for oil and gas, but also for water, are equipped with a special bus system, the <a href="https://m-bus.com/">M-BUS or meter bus,</a> for monitoring consumption values.This article describes how such meters can be read out via the M-BUS interface using a special <a href="https://www.hwhardsoft.de/english/projects/m-bus-mkr-shield/">M-BUS MKR Shield</a> connected to an Arduino Portenta H7 running MicroPython.<figure><img src=https://projects.arduinocontent.cc/15daa927-1583-4787-ab03-9c121ca0367b.jpg /><figcaption>M-BUS installation with Arduino M-BUS Shield</figcaption></figure><h3 >Install MicroPython on Portenta</h3>In addition to C++ programming via the Arduino IDE, the Arduino Portenta can also run MicroPython scripts. In order to be able to use MicroPython on the Portenta board, the OpenMV IDE must be installed on your computer and then the MicroPython interpreter must be set up on the Portenta via OpenMV.Please follow this<a href="https://docs.arduino.cc/tutorials/portenta-h7/openmv-cheat-sheet"> tutorial to install OpenMV</a> on your system.<h3 >Install the Meterbus library &amp; examples</h3>After successfully setting up OpenMV on your computer and the Portenta, a new drive will appear on your computer that stores the MicroPython scripts on the Portenta.The MicroPython code from our <a href="https://github.com/HWHardsoft/micropyMeterBus">GITHUB repository</a> is now copied to this drive, including the subdirectory.Since MicroPython does not contain any floating-point libraries, the 'mpy_decimal' directory must also be copied from the <a href="https://github.com/mpy-dev/micropython-decimal-number">micropython-decimal-number repository</a>.<figure><img src=https://projects.arduinocontent.cc/09bcedad-11e1-4b34-955b-a3c41ac2bb94.png /><figcaption>Portenta drive with files and subfolders</figcaption></figure><h3 >Running the examples</h3>Our code includes 3 example scripts. You can open these scripts via OpenMV IDE. Please ensure that the Portenta configuration lines are properly enabled/disabled in these examples:<figure><img src=https://projects.arduinocontent.cc/6c11f87c-25a9-4de4-b391-affdf4850615.png /><figcaption>disable the Pico lines and enable the Portenta lines</figcaption></figure>Don't forget to activate the terminal window below. Now you can run any of these 3 examples in OpenMV by pressing the green arrow button in the lower left corner:<figure><img src=https://projects.arduinocontent.cc/d5e1f0e4-cd86-422f-b743-24002030fbd3.jpg /><figcaption>Terminal Window output</figcaption></figure>

Smartmetering with Portenta H7

Use the Portenta H7 for smartmetering via MicroPython and Arduino MKR M-BUS shield