This Readme covers the steps I took to develop a simple wireless sensing system. In this instance I am using a picking up vibrations, but it could be any physical signal.
The project utilises development kit in order to prove a concept and consists of a 9 axis bno055 orientation sensor from Bosch, a Esp32 devkit2 in order to prepare the signals for MQTT and a Raspberry Pi to receive the data through a python program. An instance of InfluxDB and Grafana are running on the pi. Grafana is accessible through Nginx as reverse proxy so that the values can be monitored from the internet.
Hopefully this readme is clear if not then messaage me we can work through any issues and update the readme.
run the following commands from the terminal in your pi
apt update+upgrade
sudo apt-get update && sudo apt-get upgrade
python3 --version
wget https://www.python.org/ftp/python/3.9.5/Python-3.9.5.tgz
tar -zxvf Python-3.9.5.tgz
set this flag, it enables Profile guided optimization (PGO) and Link Time Optimization (LTO). It will slow down the build process but yield a 10-20% speed boost. cd Python-3.9.5 ./configure --enable-optimizations
sudo make altinstall
(if continuing from above then cd out of python dir)
install mosquitto and python
sudo apt-get install -y mosquitto mosquitto-clients python3-pip
install paho python library
python3 -m pip install paho-mqtt
nano into the follwoing
sudo nano /etc/mosquitto/mosquitto.conf
append these lines to the end of the file
listener 1883
listener 9001
protocol websockets
sudo systemctl status mosquitto
Stop the service
sudo systemctl stop mosquitto.service
start in verbose mode
mosquitto -v #start in verbose mode
open 2 terminals in putty or on the raspbery Pi GUI and in one terminal type
mosquitto_sub -d -v -t 'test/topic'
in the other
mosquitto_pub -t 'test/topic' -m 'Helloworld'
The message should show on the subscriber.
The ESP32 program is found in the main repository the flowchart below details the flow of the program
InfluxDB can be installed by directly querying the official repositories of this tool. First, add them to your list, by typing the following commands:
sudo curl -sL https://repos.influxdata.com/influxdb.key | sudo apt-key add -
sudo echo "deb https://repos.influxdata.com/ubuntu bionic stable" | sudo tee /etc/apt/sources.list.d/influxdb.list
sudo apt update
Once the list of repositories has been updated, proceed with the installation of InfluxDB using the command:
sudo apt install influxdb
after install enable it on startup
sudo systemctl enable --now influxdb
and check that it is running
sudo systemctl status influxdb
pip install influxdb
sudo apt-get install python-influxdb
To install the latest Grafana Enterprise edition:
sudo apt-get install -y apt-transport-https
sudo apt-get install -y software-properties-common wget
wget -q -O - https://packages.grafana.com/gpg.key | sudo apt-key add -
Add this repository
echo "deb https://packages.grafana.com/enterprise/deb stable main" | sudo tee -a /etc/apt/sources.list.d/grafana.list
After you add the repository:
sudo apt-get update
sudo apt-get install grafana-enterprise
check grafana is running
sudo systemctl status grafana-server
set the server to start at boot
sudo systemctl enable grafana-server.service
navigate to your raspbery pi IP address and port 3000 in your web brower
pi-ip:3000
eg 192.168.2.8:3000
you should see the grafana spash screeen, you can login to by using admin/admin and change from there.
go to configurations tab and then data sources
configure your DB ip addrees to http://localhost:8086 if this is the case
enter the DB infromation in this case I am using example save and test, ensure it is working.
Select add and dashbaord, new panel
setup the query for your dataset
The Python program can be found in the repo, the function that does the work is the On_message function, it
1.receives mqtt msg as byte array 2. converts to float 3.write float data point to influxDB
The remainder of the program is setting up clients for MQTT and Influx.
nginx is a powerful fast webserver and reverse proxy, I will concentrate on the points required for our purpose. This installation was on the raspberypi. I did not have to alter the firewall but it may be neccessary in your case.
sudo apt update
sudo apt install nginx
check that nginx is running
sudo systemctl status nginx
open a web browser and type your ip address. You should get the nginx welcome screen.
With that complete we need to point it to our grafana
First is to setup a default index page, it wont be used for this task, but it is a good skill to learn. We will configure the reverse proxy in the next step.
sudo mkdir -p /var/www/your_domain/html
set the permissons to the directories so that they allow the owner to read, write, and execute the files while granting only read and execute permissions to groups and others.
sudo chmod -R 755 /var/www/your_domain
create a sample index.html page using nano or vim
nano /var/www/your_domain/html/index.html
In order for nginx to to serve the webpage we need to create 2 server blocks. one to serve the main page and one to reverse proxy the subdomain to the grafana GUI.
navigate to
/etc/nginx/sites-available/your_domain
add the folllowing code with your details.
#Server block to serve main page
server {
listen 80 default_server;
listen [::]:80 default_server;
root /var/www/yourdomain.net/;
index index.html;
server_name yourdomain.net www.yourdomain.net;
location / {
try_files $uri $uri/ =404;
}
}
#Server block to serve port 3000 to the sub-domain
server {
listen 80;
server_name yoursubdomain.yourdomain.net;
location / {
proxy_set_header Host $host;
proxy_pass http://127.0.0.1:3000;
proxy_redirect off;
}
}
enable the file by creating a link from it to the sites-enabled directory
sudo ln -s /etc/nginx/sites-available/your_domain /etc/nginx/sites-enabled/
You need to delete the default file from the sites-available and sites-enabled dir
sudo rm default
finally check the configration of the nginx file
sudo nginx -t
if its all good then resrart Nginx
sudo systemctl restart nginx
navigate to the domain and check its all working.
This is mostly going to be outside the scope of this guide, you need to consult your routers documnetation. The outcome is going to be that your router receives the data from the sensor from the ESP32 on port 1883 on its external IP address and forwards it to the raspberry pi on your internal IP address on the same port number.
Get yourself over to google and buy a domain name you need to setup the records to point to the IP of your RaspberryPi setup a subdomain for the grafana dashbaord.
