Raspberry Pi & Arduino - Serial connection

Erasmus+ SmartHouse Project

This repository was created for Eramsmus+ project. It will let you create Raspberry Pi Flask web server from which through USB (serial) you can control/recieve and send data to the Arduino and display them on the web page in real-time. This is main functional part of the project and there are several possibilities how to expand it.

Annotation

This code was created by Czech group as part for Erasmus+ project. The goal of the project was constructing a functional model of Smart house, which can be built in every country in Europe. Therefore, we had to have in mind every weather condition which can appear. We collaborated with 5 other countries - Poland, France, Spain and Germany. Each country which participated had assigned work in the project. I have chosen this project because it is one of the most interesting projects which I have participated on in our school and as a Erasmus+ project it will have an impact on an current situation and answer real problems. We the Czech IT group, developed “smart” part of the project, which controls the whole house, for example controlling and stabilizing temperature and humidity, light control and garden watering system. My part in this project was to create and configure core computer and connect sensors to it, therefore it could gather actual information and display them on the webpage (which was made by my co-worker Adam Skokan) in real time. Additionally, I added access point (Wi-Fi), which can be connected to a user and control the house without a cable. Patrick Tsidina, who is my co-worker, is programming sensors and their automation. My contribution to the project can be divided into four parts, which are completely documented on GitHub repository, which I created for this purpose. The majority of work in the first part of the project was about gathering information and choosing the best possible solution for the task. There were multiple possibilities for approaching the right solution. After many attempts to get the best result and researching multiple frameworks, for example Blynk and Home Assistant, I decided to fully develop my own application in python with help of Flash framework and Jijja2 templating system. In a second part, I connected the core computer to the Arduino and created demo website, with two buttons for led diode control (lights demo) and value, which is generated for demo purpose on Arduino as temperature value, from the Arduino computer. I also chose and ordered computers for the project. In third part I extended website with input for numbers, which let the user set their favourite temperature. After the form is submitted, the request is sent to the Arduino and Arduino will sent it back and it as actual user set temperature value. This was created to demonstrate serial transfer. I also added database and JSON API for storing and accessing data, so Adam can use them in a graph. In the fourth part, I spent the majority of time consulting and discussing Adam’s and Patrick’s parts, but I also fully installed my software on all 5 computers and wrote the documentation and installation guide. In conclusion I sincerely believe that my part of the project is well accomplished. Everything is documented on GitHub as I mentioned before, and my work can be easily demonstrated there. The Erasmus+ project was created under the European Union. I hope that some relevant answers will come out of our solution and If not, it can be helpful just for regular users of GitHub who can use it as Home management system.

Installation

Raspberry Pi

Downloading on SD card

Download Etcher and install it on your computer.
Download Raspbian Stretch Lite from the official Raspberry Pi.
Plug your SD card into computer.
Open Etcher and select from your hard drive the Raspberry Pi .img or .zip file you wish to write to the SD card.
Select the SD card you wish to write your image to.
Review your selections and click 'Flash!' to begin writing data to the SD card.
Plug your SD card into Raspberry Pi connect HDMI, keyboard and power cable.

First boot

Login with these credentials - Login is "pi" and password is "raspberry". (Password cannot be seen)
Configure raspberry with command sudo raspi-config.
Go to Advanced options and Expand filesystem and
Go to Change user password for changing default password and confirm with OK. Write your password 2 times and confirm with OK.
Go to Network settings and Hostname for changing hostname. Acknowledge the conventions and confirm by pressing OK. Write your hostname and confirm again.
Setup Wi-Fi or connect Ethernet cable. (I haven't programmed that path yet)
Click on Finish on the bottom.
Update Raspberry Pi with command sudo apt-get update && upgrade. Type YIf needed.
Reboot Raspberry Pi using command sudo reboot -t 0

Installation of packages

Install necessary packages with command sudo apt install apache2 libapache2-mod-wsgi python-setuptools python-serial python-flask. Type Y If needed.

SSH

Enable SSH with command sudo systemctl enable ssh and sudo systemctl start ssh. You should be able to connect through console from your computer connected to the same network. You can connect on iOS through console with SSH command and on Windows through PuTTy. You can find your IP in your router settings.

Samba

Install necessary packages with command sudo apt-get install samba samba-common-bin. Type Y If needed.
Configure samba by opening sudo nano /etc/samba/smb.conf and set up properties. (optional).
Add samba user and setup password for it - sudo smbpasswd -a pi. (pi is the password)
Restart the Samba utility - sudo service smbd restart.

Core files

Clone this repository git clone https://github.com/TheLupp/EraRaspArd28.git.
Create web server folder sudo mkdir /var/www/server.
Copy files from cloned repository into server folder - sudo cp -a EraRaspArd28-master/. /var/www/server/.
Delete previous Apache config - sudo a2dissite 000-default.

Configure Apache with new config bellow over here sudo nano /etc/apache2/sites-available/.

    WSGIDaemonProcess server user=pi group=www-data threads=5
    WSGIScriptAlias / /var/www/server/server.wsgi

    
      WSGIProcessGroup server
      WSGIApplicationGroup %{GLOBAL}
      Order allow,deny
      Allow from all
      #Require all granted

Enable mod_wsgi module - sudo a2enmod wsgi.
Reload Apache - sudo systemctl restart apache2.

Access point

Install necessary packages with command sudo apt-get -y install hostapd dnsmasq. Type Y If needed.
Edit the dhcpcd file - sudo nano /etc/dhcpcd.conf and add denyinterfaces wlan0 at the bottom and save.

Edit interfaces file - sudo nano /etc/network/interfaces and add at bottom this:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet static
    address 192.168.28.1
    netmask 255.255.255.0
    network 192.168.28.0
    broadcast 192.168.28.255

Configure hostpd sudo nano /etc/hostapd/hostapd.conf.

interface=wlan0
driver=nl80211
ssid=SmartHouse28
hw_mode=g
channel=6
ieee80211n=1
wmm_enabled=1
ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40]
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_passphrase=erasmus28
rsn_pairwise=CCMP

Configure path to hostpd sudo nano /etc/default/hostapd. Find the line #DAEMON_CONF="" and replace it with: DAEMON_CONF="/etc/hostapd/hostapd.conf".
Configure Dnsmasq for automatically assigning IP addresses

Backup current dnsmasq - sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.bak Edit sudo nano /etc/dnsmasq.conf and add into blank file this:
```
interface=wlan0 
listen-address=192.168.28.1
bind-interfaces 
server=8.8.8.8
domain-needed
bogus-priv
dhcp-range=192.168.28.100,192.168.28.200,24h
```
Reboot the Raspberry PI - sudo reboot.

NAT

Edit the sysctl file - sudo nano /etc/sysctl.conf and look for the line #net.ipv4.ip_forward=1, and uncomment it by deleting the #.

Bunch of commands - blah blah blah

sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE  
sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT
sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"

Edit the rc.local file - sudo nano /etc/rc.local Just above the exit 0 line (which ends the script), add the following: iptables-restore < /etc/iptables.ipv4.nat and sudo reboot.

Arduino

Download Arduino IDE and install it on your computer.
Upload arduino-ir.ino to your board.
Connect Arduino to Raspberry through Serial/USB cable.

YOU ARE READY!

ERRORS

Internal Server Error

In order to successfully start Flask server on Raspberry Pi you need to connect with USB/Serial Arduino.

Solution 1. - Delete *.pyc (with c!) - sudo rm *.pyc & Delete database.jsou - sudo rm database.json and reboot.
Solution 2. - If you are not using original Arduino go to pyduino.py (sudo nano pyduino.py) and change connection from /dev/ttyACM0 to /dev/ttyAMA0 and save + reboot.

URLs

Raspberry Pi Official Image of Raspbian Stretch Lite - Here
Official Arduino software - Here

Lupphes/EraRaspArd28