uVOC

Java client to pull sensor data from an attached uThing::VOC sensor and publish it to an MQTT broker

Basic function

Every time the uVOC sends sensor data it is published to the MQTT broker.

The truth is in the code ;-)

Polling

This code is expected to run forever. The main loop is defined like this:

Running from commandline

Download the JAR with the dependencies. Create a file named UVOC.properties near to the JAR with the following content:

MQTT.Password=<<password>>
MQTT.Server=tcp\://<<IP>>\:<<port>>
MQTT.Topic=dl2sba.de/sensorData/%d/%d
MQTT.User=dl2sba
MQTT.nodeId=9800
MQTT.qos=1
MQTT.sensor.IAQ.id=5
MQTT.sensor.gasResistance.id=4
MQTT.sensor.humidity.id=1
MQTT.sensor.iaqAccuracy.id=6
MQTT.sensor.pressure.id=3
MQTT.sensor.temp.id=0
Runner.endWithLF=true
Runner.sleep=1
UVOC.ComPort=<<the serial port>>
UVOC.datarate=4
UVOC.json=j

Create a file named UVOC.log4j2.xml near to the JAR with the following content:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<Configuration status="info" monitorInterval="30">
	<Appenders>
		<Console name="Console" target="SYSTEM_OUT">
			<PatternLayout
				pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{1} %M - %msg%n" />
		</Console>
	</Appenders>
	<Loggers>
		<Root level="info">
			<AppenderRef ref="Console" />
		</Root>
	</Loggers>
</Configuration>

Launch the JAR with java -Dlog4j.configurationFile=UVOC.log4j2.xml -DUVOC.properties=UVOC.properties-jar uVOC-1.6-jar-with-dependencies.jar

Running using systemd

Tested on an Raspberry Pi 3 with "Linux UVOC 4.19.97-v7+ #1294 SMP Thu Jan 30 13:15:58 GMT 2020 armv7l GNU/Linux" based on this post.

Copy the following files to the desired [location]:

• UVOC.properties
• UVOC.log4j2.xml
• uVOC-1.6-jar-with-dependencies.jar

Easiest way is to copy them into the users home directory.

Create file /etc/systemd/UVOC.service with the following content:

[Unit]
Description=UVOC Service

[Service]
#  User must be member of dialout group to have access to serial port
User=[desired user to run as]

# The configuration file application.properties should be here:
WorkingDirectory=[location]
ExecStart=/usr/bin/java -Dlog4j.configurationFile=UVOC.log4j2.xml -DUVOC.properties=UVOC.properties -jar uVOC-1.6-jar-with-dependencies.jar
SuccessExitStatus=143
TimeoutStopSec=10
Restart=on-failure
RestartSec=30

[Install]
WantedBy=multi-user.target

After creating this file reload the systemd config with sudo systemctl daemon-reload.

Starting the daemon manually sudo systemctl start UVOC.

Stopping the daemon manually sudo systemctl stop UVOC.

Query the status of the daemon sudo systemctl status UVOC.

credits

This work is based on the published information from Ohmtech.io / uThing::VOC See also https://github.com/ohmtech-io/uThingVOC