A fullstack Arduino temperature monitor

Up and Running

Arduino

Configure the firmware

Before everything else, you need to configure your arduino firmware to connect to your backend server. There is a script for that called configure.sh. This script takes 2 arguments, the first is the hostname where you deployed your backend and the second is the port. Example:

./configure.sh backend.project.com 8080

If everything is ok, you will get the output:

$./configure.sh backend.project.com 8080
[+] Configuring backend server
[+] Generating source files
[+] Done

Arduino components & wiring

The components that you will need to setup this experiment:

• Arduino Uno R3
• Ethernet shield
• DHT11 - Temperature and Humidity sensor
• Cables
  • Ethernet cable
  • Power cable for arduino
  • 3 male -> female jumpers

The wiring is very simple, just install the ethernet shield, wire the DHT11 pins to:

• VCC - 5V
• GND - Ground
• Data - Arduino digital pin 3.

Compile and upload the firmware

You can use the strm/dev-arduino docker image to build this repository, just cd into the arduino folder and run

docker run --rm -it -v "$(pwd):/src" strm/dev-arduino build

If you don't have the image locally it will be downloaded, and this will be the output of a successful compilation.

Searching for Board description file (boards.txt) ... /usr/share/arduino/hardware/arduino/boards.txt
Searching for Arduino lib version file (version.txt) ... /usr/share/arduino/lib/version.txt
Detecting Arduino software version ...  1.0.5 (2:1.0.5+dfsg2-4)
Searching for Arduino core library ... /usr/share/arduino/hardware/arduino/cores/arduino
Searching for Arduino standard libraries ... /usr/share/arduino/libraries
Searching for Arduino variants directory ... /usr/share/arduino/hardware/arduino/variants
Searching for make ... /usr/share/arduino/hardware/tools/avr/bin/make
Searching for avr-gcc ... /usr/share/arduino/hardware/tools/avr/bin/avr-gcc
Searching for avr-g++ ... /usr/share/arduino/hardware/tools/avr/bin/avr-g++
Searching for avr-ar ... /usr/share/arduino/hardware/tools/avr/bin/avr-ar
Searching for avr-objcopy ... /usr/share/arduino/hardware/tools/avr/bin/avr-objcopy
src/sketch.ino
Searching for Arduino lib version file (version.txt) ... /usr/share/arduino/lib/version.txt
Detecting Arduino software version ...  1.0.5 (2:1.0.5+dfsg2-4)
Scanning dependencies of src
Scanning dependencies of arduino
Scanning dependencies of dht
Scanning dependencies of SPI
Scanning dependencies of Ethernet
src/sketch.cpp
dht/dht.cpp
Linking libdht.a
Ethernet/Dhcp.cpp
Ethernet/EthernetServer.cpp
Ethernet/Ethernet.cpp
Ethernet/EthernetClient.cpp
Ethernet/utility/socket.cpp
Ethernet/utility/w5100.cpp
Ethernet/EthernetUdp.cpp
Ethernet/Dns.cpp
Linking libEthernet.a
SPI/SPI.cpp
Linking libSPI.a
arduino/avr-libc/realloc.c
arduino/avr-libc/malloc.c
arduino/wiring_shift.c
arduino/wiring_digital.c
arduino/wiring.c
arduino/wiring_analog.c
arduino/WInterrupts.c
arduino/wiring_pulse.c
arduino/Stream.cpp
arduino/Tone.cpp
arduino/HardwareSerial.cpp
arduino/CDC.cpp
arduino/Print.cpp
arduino/USBCore.cpp
arduino/main.cpp
arduino/WMath.cpp
arduino/new.cpp
arduino/HID.cpp
arduino/WString.cpp
arduino/IPAddress.cpp
Linking libarduino.a
Linking firmware.elf
Converting to firmware.hex

After a successful compilation, connect your arduino to the USB port and run this command, in the same folder

docker run --rm -it -v "$(pwd):/src" --device=/dev/ttyUSB0 strm/dev-arduino upload

Considering that your Arduino is mapped to your USB located at /dev/ttyUSB0. Your result will be:

Searching for stty ... /bin/stty
Searching for avrdude ... /usr/share/arduino/hardware/tools/avrdude
Searching for avrdude.conf ... /usr/share/arduino/hardware/tools/avrdude.conf
Guessing serial port ... /dev/ttyUSB0

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e950f
avrdude: reading input file ".build/uno/firmware.hex"
avrdude: writing flash (16054 bytes):

Writing | ################################################## | 100% 2.66s

avrdude: 16054 bytes of flash written
avrdude: verifying flash memory against .build/uno/firmware.hex:
avrdude: load data flash data from input file .build/uno/firmware.hex:
avrdude: input file .build/uno/firmware.hex contains 16054 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 2.14s

avrdude: verifying ...
avrdude: 16054 bytes of flash verified

avrdude: safemode: Fuses OK (E:00, H:00, L:00)

avrdude done.  Thank you.

Backend

Docker setup

You will need docker to run this project, so you can download and install it with this command

curl -fsSL https://get.docker.com/ | sh

And docker compose with

curl -L "https://github.com/docker/compose/releases/download/1.8.1/docker-compose-$(uname -s)-$(uname -m)" > /usr/local/bin/docker-compose
chmod +x /usr/local/bin/docker-compose

Start the backend

Just go to the folder where your docker-compose.yml is located and run

docker-compose up

It will start the whole stack.

Influxdb configuration

To access your Influxdb admin interface go to your backend at port 8083. You will be presented to this page

We will need to create our database to store the input data, so let's create a database named temperature. Execute this query:

CREATE DATABASE "temperature"

If everything went fine, you will be presented to this page

Grafana configuration

The very next step it to configure Grafana, where our data will be rendered.

Create datasource

Datasource creation is really simple, just run the script bellow and everything will be configured for this environment:

BACKEND='backend.project.com'
curl 'http://admin:admin@'$BACKEND':3000/api/datasources' -sq | grep sensors > /dev/null || curl 'http://admin:admin@'$BACKEND':3000/api/datasources' -X POST -H 'Content-Type: application/json;charset=UTF-8' --data-binary '{"name":"sensors","type":"influxdb","url":"http://database:8086","access":"proxy","isDefault":true,"database":"temperature"}'

Just replace the BACKEND variable with the location of your Grafana server.

Import the dashboard

The very next step is to import the dashboard, you don't need to create one, use this one. Access your Grafana interface at your backend host at the port 3000. You will be presented to this page

The default username is admin and the password too. Then go to New Dashboard.

You can import a dashboard by clicking in the left menu and going into Import

Choose the dashboard.json file and you will get an empty dashboard, that after a while, will be filled with enought data like this.

Test backend with mock data

You can send some sample data to feed your backend, here is an example using curl

BACKEND='backend.project.com'
while true; do clear; date; curl -XPOST -H "Content-Type: application/json" -d '{"type": "temperature", "value": '$(( ( RANDOM % 30 )  + 5 ))',"device": 1,  "sensor": 123 }' http://$BACKEND:8080/temperature; sleep 4;done;

Just replace the BACKEND variable with the location of your backend server. So you can troubleshoot what is happening and test the whole backend stack.

Security notice

As you can notice, all passwords are default, all services are exposed, and there is no security control, this is just a POC, but I strongly recommend that you don't deploy it in a production environment.