TempSensor

Hardware Requirement

• Rpi Zero W
• Temperature sensor DS18B20

Building

Usage.

$ tempsensor <settings.ini>

Build.

• mkdir build
• cd build
• cmake ..
• cd ..
• make -C build
• sudo ./build/tempsensor

Build gtests.

• mkdir build
• cd build
• cmake .. -Dunittest=ON
• cd ..
• make -C build
• ./build/runUnitTests

Dependecy.

• libsqlite3-dev
• libmosquitto-dev
• libmosquittopp-dev

settings.ini

# This files contains all settings temperaturesensor,
# edit to fit your needs.
[SensorSettings]
sensor=28-0417a2f482ff
[SQLite]
db_file=./testdata/temperature.db
[Mqtt]
ID=foo1
server=m24.cloudmqtt.com
port=15786
username=test
password=test

[Topic1]
topic=playground
#interval given in minutes
interval=1

[Topic2]
topic=playground_history
#interval given in minutes
interval=1

Frontend

A simple webpage with a basic js mqtt client. Displaying current temperature and the temperature for the last 24h. Edit to fit your needs.

Hardware

Setup DS18B20

Your DS18B20 should be connected to pin 7 (BCM4), gnd, and 3v.

Edit /boot/config.txt

# Enable gpio for DS18BS20
dtoverlay=w1-gpio,pinout=4,pullup=on

Edit /etc/modules

# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.
w1-gpio pullup=1
w1-therm strong_pullup=1

check for /sys/bus/w1/devices/28-xxxxxxxxxx

Autostart with systemd

To autostart the sensor at boot (or restart if it crash) use systemd.

$ mkdir ~/bin
$ cp <src_path>/build/tempsensor ~/bin/
$ cp <src_path>/systemd/start_sensor.sh ~/bin/
$ sudo cp <src_path>/systemd/tempsensor.service /etc/systemd/system/tempsensor.service
$ sudo systemctl enable tempsensor.service
$ sudo systemctl start tempsensor.service

Licens (Zero Clause BSD)

    Copyright (C) 2019, Fredrik Persson <[email protected]>

    Permission to use, copy, modify, and/or distribute this software
    for any purpose with or without fee is hereby granted.

    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
    AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
    INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
    LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
    OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
    OF THIS SOFTWARE.