MBusPico

NEW IN VERSION 2.0: ADDED MICROPYTHON AND PYTHON SUPPORT. RASPBERRY PI IS NOW SUPPORTED. ADDED READY-TO-USE DOCKER IMAGE

This project was created mostly out of interest and the wish to read out and display my power meter data in my Loxone smart home setup. (Thus the option with the 24V power supply - see below)

Currently the only smart meter device supported is the Kaifa MA309M (Austrian power provider Netz NÖ), but could be extended to any other model. Credits for the data intepretation code goes out to firegore/esphome-dlms-meter!

The read meter data values are published via HTTP and/or UDP in JSON format:

Field	Description / Unit
timestamp	Timestamp of the reading in the format "0000-00-00T00:00:00Z"
lxTimestamp	Loxone timestamp (seconds since 1.1.2009)
meterNumber	serial number of the meter device
activePowerPlus	[W]
activePowerMinus	[W]
activeEnergyPlus	[Wh]
activeEnergyMinus	[Wh]
voltageL1	[V]
voltageL2	[V]
voltageL3	[V]
currentL1	[A]
currentL2	[A]
currentL3	[A]
powerFactor	see Wikipedia

{
"timestamp": "2022-11-20T19:03:40Z",
"lxTimestamp": 438203020,
"meterNumber": "123456789012",
"activePowerPlus": 472.00,
"activePowerMinus": 0.00,
"activeEnergyPlus": 1385960.00,
"activeEnergyMinus": 0.00,
"voltageL1": 235.00,
"voltageL2": 234.30,
"voltageL3": 235.00,
"currentL1": 1.72,
"currentL2": 0.17,
"currentL3": 0.99,
"powerFactor": 823.00
}

Hardware

• RaspberryPi Pico W(H)
• M-BUS SLAVE CLICK module
• RJ11/RJ12 cable (or an old telephone cable you may have lying around)
• [24V -> 3.3V step down regulator]
  • Example (used in 3d case v2)
  • Example
• power connector clamp (optional)

Note: the links of the above listed hardware components to Amazon are exemplary. If you want to support me you can use them to order the linked products using these links.

Software

There are two versions of MBusPico available:

There is a native Raspberry Pico application written in C using the following components:

• pico-sdk
• FreeRTOS
• mbedtls
• mongoose

And (since v2.0) there is also a Python/Micropython version available, using the following moduls:

• microdot
• PySerial
• PyCryptodome

Build (native application)

1. Download and extract latest release archive - or clone repository: git clone --recurse-submodules https://github.com/raven-worx/MBusPico.git
2. Edit build options (see below) in options.ini to configure MBusPico application to your needs
3. start building (e.g. using Docker - see below)

Linux

Simply run the build.sh script.

Make sure you have set the PICO_SDK_PATH environment variable pointing to your local pico-sdk checkout. If you do not have a checkout of the pico-sdk yet, you can instead add the option PICO_SDK_FETCH_FROM_GIT=ON in the options.ini file to automatically checkout the pico-sdk as part of the build process.

Windows

For Windows i recommend using Docker for a quick and painless build.

You can also use the already available prebuilt docker image ravenworx/pico-sdk-build:1.5.0 which contains already all required packages to build MBusPico.

docker run -v ${PWD}:/opt/mbuspico --entrypoint=/opt/mbuspico/build.sh ravenworx/mbus-pico-build:1.5.0

Alternatively you can create a (local) docker image with the file provided in the docker folder of this repository.

docker build -t my/mbuspico-build -f docker/Dockerfile

After the build of the docker image has finished (might take a few minutes) simply start the built with the my/mbuspico-build instead.

Build options

Option	Default value	required	Description
MBUSPICO_DEVICE_KEY		yes / device dependant	Key used to decrypt data read from the meter. Must be requested from the power provider.
MBUSPICO_LOG_LEVEL	LOG_ERROR	no	level of log verbosity. Possible values: LOG_NONE, LOG_ERROR, LOG_INFO, LOG_DEBUG
MBUSPICO_WIFI_ENABLED	ON	no	specifies if the device should connect to wifi network
MBUSPICO_WIFI_SSID		yes, if MBUSPICO_WIFI_ENABLED	Wifi SSID to connect to
MBUSPICO_WIFI_PWD		yes, if MBUSPICO_WIFI_ENABLED	Wifi password
MBUSPICO_WIFI_HOSTNAME	"MBusPico"	no	The hostname of the Pico W device in the network
MBUSPICO_UDP_ENABLED	OFF	no	specifies if the device should send out the read meter data via UDP
MBUSPICO_UDP_RECEIVER_HOST		yes, if MBUSPICO_UDP_ENABLED	the UDP receiver address the meter data packet should be send to
MBUSPICO_UDP_RECEIVER_PORT		yes, if MBUSPICO_UDP_ENABLED	the UDP receiver port the meter data packet should be send to
MBUSPICO_UDP_INTERVAL_S	30	no	the maximum interval [sec] the meter data should be send out via UDP
MBUSPICO_HTTP_ENABLED	ON	no	specifies if the device should launch a simple HTTP server to provide the read meter data
MBUSPICO_HTTP_SERVER_PORT	80	no	specifies the listening port for the HTTP webserver
MBUSPICO_HTTP_AUTH_USER		no	Protect access to data with authentication
MBUSPICO_HTTP_AUTH_PWD		no	Protect access to data with authentication

Transfer MBusPico onto the device

Native application

Hold the BOOTSEL button on the Raspberry Pico W while connecting it to the PC via a USB cable. Since v1.2 its also possible to call http://<ip-address>/update to restart into the bootloader (if built with HTTP option). The Pico will show up as a flash drive. Copy the mbuspico.uf2 file from the build directory to the appeared flash drive. The Pico W will automatically reboot into the just flashed firmware after copying has finished. Done.

MicroPython application

To copy MicroPython to the Raspberry Pico, hold the BOOTSEL button on the Raspberry Pico W while connecting it to the PC via a USB cable and copy the micropython.uf2 to the appeared flash drive.

Important: MBusPico requires MicroPython with built-in support for AES-CTR ciphre, which is disabled by default in the official release builds. A prebuilt MicroPython version can be found in the python archive of each MBusPico release (since v2.0 onwards), or in the python directory of this respository.

Now make sure you have adapted config.py to your needs before you copy all folders and files from python/dist to the Raspberry Pico:

For example you can use Thonny IDE to transfer files to the Raspberry Pico.

Or via command line using python3/pip3 with the following commands. On Windows make sure python3.exe can be found in the PATH. Probably the easiest is to install Python3 from the Windows Marketplace.

Install ampy CLI tool:

pip3 install adafruit-ampy

Use ampy to copy files and folders to device. <PORT> must the serial port of the connected Raspberry Pico running MicroPython. e.g. Linux: /dev/ttyS0, Windows COM5 To see a list of available serial ports you can run python3 -m serial.tools.list_ports

cd python/dist
ampy --port <PORT> put mbus
ampy --port <PORT> put provider
ampy --port <PORT> put config.py
ampy --port <PORT> put main.py

HTTP endpoints

When built with MBUSPICO_HTTP_ENABLED option enabled the following HTTP endpoints are provided.

Method	Endpoint URL	Description
GET	/	Return last read meter data in JSON format
GET	/update	Reboot device into USB bootloader for a quick and easy update of MBusPico application (only available on Raspberry Pico)
GET	/reboot	Reboot device (only available on Raspberry Pico)

Hardware wiring / assembly

Raspberry Pico W

Pico W	M-Bus Slave CLICK	RJ11	Notes
GPIO4 (PIN 6)	RX	-	UART RX of MBUS module <--> UART1 TX of Pico W
GPIO5 (PIN 7)	TX	-	UART TX of MBUS module <--> UART1 RX of Pico W
-	MBUS1	3	MBUS module to RJ11 cable line 3 or 4 (polarity doesn't matter)
-	MBUS2	4	MBUS module to RJ11 cable line 3 or 4 (polarity doesn't matter)

Power supply (24V):

Pico W	M-Bus Slave CLICK	24V -> 3.3V module	24V power source	Notes
VSYS (PIN 39)	-	VOUT		3.3V power supply for Pico W
GND (PIN 38)	-	GND		Ground
-	3V3	VOUT		3.3V power supply for MBus CLICK module
-	GND	GND		Ground
-	-	VIN	DC+/24V	24V external power supply
-	-	GND	DC-/GND	Ground

Raspberry Pi

Raspberry Pi	M-Bus Slave CLICK	RJ11	Notes
GPIO14 (PIN 8)	RX	-	UART RX of MBUS module <--> UART TX of Raspberry Pi
GPIO15 (PIN 10)	TX	-	UART TX of MBUS module <--> UART RX of Raspberry Pi
-	MBUS1	3	MBUS module to RJ11 cable line 3 or 4 (polarity doesn't matter)
-	MBUS2	4	MBUS module to RJ11 cable line 3 or 4 (polarity doesn't matter)

Power supply (24V):

Raspberry Pi	M-Bus Slave CLICK	24V -> 5V module	24V -> 3.3V module	24V power source	Notes
5V	-	VOUT+			5V power supply for Raspberry Pi
5V	-	VOUT+			5V power supply for Raspberry Pi
GND	-	VOUT-			Ground
-	-	VIN+		DC+/24V	24V external power supply
-	-	VIN-		DC-/GND	Ground
-	3V3		VOUT+		3.3V power supply for MBus CLICK module
-	GND		VOUT-		Ground
-	-		VIN+	DC+/24V	24V external power supply
-	-		VIN-	DC-/GND	Ground

Loxone integration

See loxone/README.md

3D printer files

I created a 3d printable reference design of a case for the used hardware components listed above. You can find the files in the 3d folder of this repository.

License

Licensed under GPLv3