Overview

Here are links to the different board designs together with a short summary.

Board 1

The project's original board design. It

is based on the ESP8266 chip.
is powered by USB.
uses a very simple voltage divider to demodulate the M-bus signal.
has shematic and pcb design only available as finished pdf/png files.

Status

Prototypes have been made and some people have started using them(?).

Board 2

This board design is a newer alternative to the original. It

is an Arduino shield.
uses the industry standard TSS721 chip to interface the M-bus.
is optically isolated.
has shematic and pcb design available in editable KiCad source files.

Status

Unfinished, just started.

Board 3

This board is a M-bus master simulator to be able to develop and test the other boards without being dependent on having and using a real AMS unit.

Status

Implementation done.

Getting started building or modifying

Tools

Kicad

Install the KiCad program to edit the schematic or PCB. KiCad documentation and forums:

Simulator

If you want to simulate parts of the circuit you also need a simulator. This is highly recommended! This saves a lot of troubleshooting and makes you find solutions you otherwise would not have found.

Electronic circuit simulation using computers have a long history. Many of them have origins directly or indirectly related to the classic SPICE simulator (e.g. Ngspice). At the core they work similar to source code compilers - you give it a text file describing the circuit and it produces a textual simulation result. Some of the simulators are intended to be used just in text mode while other have a graphical frontend where you are able to draw the circuit like in a schematic editor:

QUCS - Quite Universal Circuit Simulator.
QUCS-S - A qucs version using ngspice as simulation backend. This one has been used for the simulations for board 3.
eSim.
Other alternatives.

Git

While it is possible to download the content from this repository as a compresset zip file, you want to use git to fetch the content. For Linux install depending on distribution with

apt-get install git   # debian, ubuntu, etc
dnf install git       # fedora
yum install git       # rhel, centos

For windows the most convenient option is to install git for windows.

To download the source of this repository run:

git clone https://github.com/roarfred/AmsToMqttBridge
cd AmsToMqttBridge
git submodule init
git submodule update --recursive