ams-han-decoder

Decoder of binary serial stream from HAN port of power meters in Norway.

Requires MBUS slave-to-serial adapter hardware. See main script for details on working configurations.

Running

See main script for details on how to use it. Run with -h for help.

Installing dependencies

Requires JSON and URI CPAN module to work. Install dependencies using your system package manager or favorite CPAN client. If you're using a Debian-based system, it is usually enough to apt-get install libjson-perl libwww-perl.

If you're using a custom Perl environment or another installation method, you can either use cpanm --installdeps . to install the dependencies where your environment expects them, or use carton install to install them in local/ and use carton exec ams_han_decoder.pl to run the script. Or you can set the environment variable PERL5LIB to local/lib/perl5 and run the binary. See Carton for more details.

Installing as a systemd service sending data to MQTT broker

This is an example of using the decoder with built in MQTT client to send the data to a MQTT broker. With the -a prefix it´s enable Home Assistant MQTT discovery and the -i prefix ignores checksum errors. Change environment variables to suit your setup.

[Unit]
Description=AMS HAN decoder
After=network.target

[Service]
Environment=HOME=/root
Environment=AMS_OBIS_MAP=XX_YY
Environment=MQTT_SERVER=mqtt://username:password@domain:port/topic
Environment=MQTT_SIMPLE_ALLOW_INSECURE_LOGIN=True
ExecStart=/bin/sh -c '/home/pi/ams-han-decoder/ams_han_decoder.pl -i -a /dev/ttyAMA0'
# Avoid memory leak eating all memory
MemoryHigh=50M
MemoryMax=100M
Restart=always
RestartSec=3

[Install]
WantedBy=multi-user.target

Installing as a systemd service shipping JSON over MQTT with mosquitto_pub

This is an example of using the decoder together with mosquitto_pub to ship the JSON messages over MQTT to its destination.

[Unit]
Description=AMS HAN decoder

[Service]
Environment=HOME=/root
ExecStart=/usr/local/bin/ams-han-decoder -m AIDON_V0001 -k -c -p 'mosquitto_pub -l -t sensor/aidon' /dev/aidon
# Avoid memory leak eating all memory
MemoryHigh=50M
MemoryMax=100M

[Install]
WantedBy=multi-user.target

Caveats

A memory leak has been detected when you use the -p parameter. It is somewhat diminished when using the -k parameter (to keep the program running between messages). It is recommended to always use -k with -p to minimize this memory leak. If you're using systemd, as above, then the limits imposed on the service should keep it somewhat under control. If you have suggestions for how to resolve this issue, please create a ticket for it. Normal memory usage is around 9MB.