Scroll to navigation

MQTT-PUBLISHER(1) LinuxCNC Documentation MQTT-PUBLISHER(1)

NAME

mqtt-publisher - send HAL pin data to MQTT broker periodically

SYNOPSIS

loadusr -W mqtt-publisher [options] keys=pin1[,pin2...]

DESCRIPTION

mqtt-publisher is a user space program that reads HAL values periodically and passes the values to a MQTT broker.

When specifying the MQTT settings in the INI file, this is the recommended setup:

HAL file:

loadusr -W mqtt-publisher [MQTT]DRYRUN --mqtt-broker=[MQTT]BROKER \


  --mqtt-user=[MQTT]USERNAME --mqtt-password=[MQTT]PASSWORD keys=halui.estop.is-activated

INI file:

[MQTT]
DRYRUN = --dryrun
BROKER = broker.local
USERNAME = username
PASSWORD = password

This component need the Paho python library installed to function. On debian this is available from the python3-paho-mqtt package.

OPTIONS

keys=pin1[,pin2,...]

The name of HAL pins, signals and other values to publish using MQTT. The names are also used as the JSON keys in the MQTT message publised with the broker.

--dryrun

Do not set up MQTT connection, only print message to stdout. Useful for debugging and testing.

--mqtt-broker=FQDN

The fully qualified DNS name of the MQTT broker. The default broker name is "localhost".

--mqtt-port=PORTNUMBER

The port to use of the MQTT broker. The default port is 1883.

--mqtt-user=USERNAME

The user name to use when connecting to the MQTT broker.

--mqtt-password=PASSWORD

The password to use when connecting to the MQTT broker.

--mqtt-prefix=PREFIX

The MQTT prefix/topic to use when publishing to the MQTT broker. The default prefix is "devices/linuxcnc/machine".

FUNCTIONS

mqtt-publisher

The loop reading HAL values and publishing MQTT messages.

PINS

mqtt-publisher.enable bit input

When TRUE, publish messages to MQTT broker. When FALSE, do not publish messages. Default is TRUE.

mqtt-publisher.period u32 input

The number of seconds to sleep between publishing MQTT messages to the broker. Default is 10 seconds.

mqtt-publisher.lastpublish u32 output

When the last MQTT publication was published in number of seconds since EPOC. If no publication has taken place, the value is zero.

EXAMPLES

Any set of HAL pins and signals can be published. This setup might be a useful starting point:

loadusr -W mqtt-publisher [MQTT]DRYRUN --mqtt-broker=[MQTT]BROKER


    --mqtt-user=[MQTT]USERNAME --mqtt-password=[MQTT]PASSWORD


    keys=halui.axis.a.pos-feedback,halui.axis.b.pos-feedback,


    halui.axis.c.pos-feedback,halui.axis.u.pos-feedback,


    halui.axis.v.pos-feedback,halui.axis.w.pos-feedback,


    halui.axis.x.pos-feedback,halui.axis.y.pos-feedback,


    halui.axis.z.pos-feedback,halui.estop.is-activated,


    halui.joint.0.is-homed,halui.joint.1.is-homed,halui.joint.2.is-homed,


    halui.joint.3.is-homed,halui.joint.4.is-homed,halui.joint.5.is-homed,


    halui.joint.6.is-homed,halui.joint.7.is-homed,halui.joint.8.is-homed,


    halui.machine.is-on,halui.max-velocity.value,halui.mode.is-auto,


    halui.mode.is-manual,halui.mode.is-mdi,halui.mode.is-teleop,


    halui.program.is-running'

Note, the list of keys can not include space after comma. The lines are only broken here to avoid too long lines in the documentation.

SEE ALSO

hal(3hal)

AUTHOR

Component and documentation created by Petter Reinholdtsen, as part of the LinuxCNC project.

COPYRIGHT

Copyright © 2023 Petter Reinholdtsen. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

02/10/2023 LinuxCNC