IoT Sensor System for Fruit Stress Monitoring in Apple Grading Industrial Processes

The project aims to develop a system to monitor the stress of apples during the grading process in industrial plants. The system is composed of three main components: the Smart Apple, the IoT Gateway, and the IoT Server. The Smart Apple is a low-cost IoT device placed inside a real apple that measures the accelerations and angular velocities of the fruit and sends the data to the IoT Gateway. The IoT Gateway is a Raspberry Pi that collects the data from the Smart Apples and sends it to the IoT Server. The IoT Server is a Raspberry Pi that stores the data in a InfluxDB database and provides a web interface to visualize the data with some impact analyses. The system is designed to be scalable and easy to deploy in industrial environments.

Operational steps

Option 1 - Only Master

Run directly the script located in data-analysis/acquisition_app.py
It will start looking for Smart Apples (Arduino Nicla) with a known MAC address and start the streaming of the BLE packets
We can save the data in a local csv (by setting the save2local flag), send it to a MQTT server (by setting the send2mqtt flag) or save it directly in the InfluxDB database (by setting the send2influxdb flag). You can also decide to activate all of them at the same time
The data saved in InfluxDB can be retrieve using the master-raspberry/test/pull_influxdb.py script (be careful of the timestamp since there is no RTC module in the Raspberry Pi and therefore it would be the best to take the last few hours or minutes instead of specifying a range).

Option 2 - Slave & Master

Raspberry Pi Master
- Run the script located in master-raspberry/app/main.py
- It will start listening to the MQTT topic and when some data is received, it will push them to the InfluxDB database
Raspberry Pi Slave
- Run the script located in slave-raspberry/app/main.py
- It will start looking for Smart Apples (Arduino Nicla) with a known MAC address and start the streaming of the BLE packets
- After receiving some packets, it will write them on the MQTT topic
The data saved in InfluxDB can be retrieve using the master-raspberry/test/pull_influxdb.py script (be careful of the timestamp since there is no RTC module in the Raspberry Pi and therefore it would be the best to take the last few hours or minutes instead of specifying a range)

Raspberry Pi 4 Set-up

Common Set-up

Set-up Modem

Enable only 2.4 GHz with a 20MHz bandwidth (disable automatic switching from 20MHz to 40MHz)
Fix the wifi channel and disable the automatic switching

Installing OS

Install Raspberry Pi Imager and open it
Press CTRL+Shift+X and modify the preferences enabling the WI-FI options
If using the modem provided by the lab the credentials are:
```
ssid: UNITN-SHIELD4US-WIFI
password: 
```
Enable SSH options and give a username and password, such as:
```
user: pi
hostname: raspPi01
password: raspberry
```
Select RASPBERRY PI OS (64-BIT)
Press WRITE to flash the micro-SD

If you want to add new wifi credentials, you can create a wpa_supplicant.conf file and place it in the root of the sd, with this content:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="UNITN-SHIELD4US-WIFI"
    psk=""
    id_str="portable_router"
}

network={
    ssid="PROVA-SSID"
    psk="PASSWORD"
    id_str="prova_access_point"
}

Update BLE stack

I have found that the bluez version 5.66 works better than others, so let’s update it (my current raspberry kernel is 6.1.21-v8+, Troubleshooting — bleak 0.21.1 documentation)

# download new version
wget http://www.kernel.org/pub/linux/bluetooth/bluez-5.66.tar.xz

# extract it and go inside the folder
tar xvf bluez-5.66.tar.xz
cd bluez-5.66

# install or update necessary dependencies
sudo apt-get install libdbus-1-dev libglib2.0-dev libudev-dev libical-dev libreadline-dev

# configure, compile and install
./configure --prefix=/usr --mandir=/usr/share/man --sysconfdir=/etc --localstatedir=/var --enable-experimental
make
sudo make install

# restart the bluetooth services
sudo systemctl daemon-reload
sudo systemctl restart bluetooth

# check bluez version
bluetoothd -v
# check kernel version
uname -r

# remove tar and folder
cd ..
rm bluez-5.66 -r && rm bluez-5.66.tar.xz

Disable Wifi Power Management

Sometimes the Raspberry disconnects on its own from the network when it is in idle. To avoid this problem we can disable the wifi power management.

Disable it temporally

# check if it is on
iwconfig wlan0 | grep "Power Management"
# disable it
sudo iwconfig wlan0 power off

To disable it every time on start-up set-up a systemctl daemon

# create a file
sudo nano /etc/systemd/system/wifi-power-management.service

# content of file
[Unit]
Description=Disable power management for wifi

[Service]
ExecStart=/sbin/iwconfig wlan0 power off
Type=oneshot

[Install]
WantedBy=multi-user.target

# save the file and enable the service
sudo systemctl enable wifi-power-management.service
# if you want to start it right away
sudo systemctl start wifi-power-management.service

Dependencies Installation

update and upgrade packages

sudo apt-get update 
sudo apt-get upgrade

clone github repo and install the dependencies

# clone repo
# insert github username and password (public token) if requested
git clone https://github.com/PeriniM/SmartApple-Thesis.git

# run bash to install everything and select whether the device is a Gateway or Server
cd ./SmartApple-Thesis
sudo chmod +x setup.sh
./setup.sh

to discard local changes and fetch updated github repo
```
git fetch --all
git reset --hard origin/main
```

IoT Gateway

Using External Bluetooth Antenna

the antenna must be compatible with bluetooth 5.0 to support BLE

disable built-in interface to use the external antenna

# check built-in interface name
hciconfig

# disable it to use new one
sudo hciconfig hci0 down

Run script on boot

IoT Server

Docker Influxdb, Grafana and Mosquitto

The following commands will set-up influxdb and grafana to run on boot inside a docker container

install docker

# install docker
curl -sSL https://get.docker.com | sh
sudo usermod -aG docker pi

# reboot
sudo reboot

# install docker compose
# sudo apt-get install libffi-dev libssl-dev
# sudo apt-get install -y python python-pip
sudo pip install docker-compose

create the container

# go inside the project folder and create the containers
docker-compose up -d --build

# stop the running containers
docker-compose down

if you get errors while installing, you need to set up the DNS properly

# Open the systemd-resolved configuration file
sudo nano /etc/systemd/resolved.conf
# uncomment the DNS line and add the google ip
DNS=8.8.8.8 8.8.4.4
# restart the service
sudo systemctl restart systemd-resolved
# to verify the new DNS conf
systemd-resolve --status

to run on boot

# create a systemd service file
sudo nano /etc/systemd/system/docker-compose-app.service

# content of the file
[Unit]
Description=Docker Compose Application Service
Requires=docker.service
After=docker.service

[Service]
WorkingDirectory=/home/pi/Desktop/SmartApple-Thesis
ExecStart=/usr/local/bin/docker-compose up
ExecStop=/usr/local/bin/docker-compose down
TimeoutStartSec=0
Restart=always
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

# reload systemd to read the new service
sudo systemctl daemon-reload

# enable the service to run on boot
sudo systemctl enable docker-compose-app.service

# start, stop, status service command
sudo systemctl start docker-compose-app.service
sudo systemctl stop docker-compose-app.service
sudo systemctl status docker-compose-app.service

if you make some changes to the docker-compose.yml

# before making changes stop the service
sudo systemctl stop docker-compose-app.service
# apply changes to docker-compose file and run
docker-compose up -d
# restart systemctl service
sudo systemctl restart docker-compose-app.service
# to see if everything is good
docker-compose logs

to stop and remove all the containers

docker container stop $(docker container ls -aq)
docker container prune -f

Set datetime

If not accessed to internet to set manually the time we can use:
```
sudo date -s '2024-01-26 13:04:00’
```

Run script on boot

Extras

Enabling VNC

Connect through SSH using a terminal or Putty
```
ssh pi@raspberrypi.local
password: raspberry
```
Update the dependencies, create a folder for autoboot applications and install LXSession
```
sudo apt-get update
sudo mkdir -p /etc/xdg/autostart/
sudo apt-get install lxsession
```
Open the options interface using sudo raspi-config and set the following to enable the GUI remote control:
1. System Options > Boot / Auto Login > Desktop Autologin
2. Display Options > VNC Resolution > 1920x1080
3. Interface Options > VNC
Reboot with sudo reboot
Download VNC Viewer, create an account and use the IP address of the raspberry to connect remotely to the GUI. To discover your device IP use the following command:
```
ifconfig
--OR--
hostname -I
```

Install Node-RED

bash <(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/master/deb/update-nodejs-and-nodered)
# to start local server
node-red-pi --max-old-space-size=256

Raspberry Pi Zero W (WORKING)

Install the OS

Check if the bluetooth interface is available and enable BLE features

# install bluetooth dependencies ([here](https://github.com/noble/noble))
sudo apt-get install bluetooth bluez libbluetooth-dev libudev-dev
# check if hci is available
hcitool dev
# check if bluetooth service is active
sudo systemctl status bluetooth
# if not, active it with
sudo systemctl start bluetooth
# open bluetooth.service file and add the --experimental flag for BLE
sudo nano /lib/systemd/system/bluetooth.service
'ExecStart=/usr/local/libexec/bluetooth/bluetoothd --experimental'

# reload the configuration and restart the service
sudo systemctl daemon-reload
sudo systemctl restart bluetooth

# set bluetoothd permission (found [here](https://flows.nodered.org/node/node-red-contrib-generic-ble))
sudo usermod -G bluetooth -a pi

# start/stop BLE advertising without sudo (found [here](https://flows.nodered.org/node/node-red-contrib-ble-sense))
sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)

# reboot
sudo reboot

Install Node-RED
Install node-red-contrib-ble-sense module and dashboard

Install BLE dependencies on Raspberry Pi 3 (NOT WORKING)

To upgrade or downgrade bluez package (guide here):

# install latest bluez version (check [here](http://www.bluez.org/download/))
cd ~
wget http://www.kernel.org/pub/linux/bluetooth/bluez-5.66.tar.xz
tar xvf bluez-5.66.tar.xz && cd bluez-5.66

# install dependencies
sudo apt-get update
sudo apt-get install -y libusb-dev libdbus-1-dev libglib2.0-dev libudev-dev libical-dev libreadline-dev

# set configure method
./configure --enable-library

# compile
make

# install package
sudo make install

# reboot
sudo reboot

# make the service start from boot
sudo systemctl enable bluetooth

# open bluetooth.service file and add the --experimental flag for BLE
sudo nano /lib/systemd/system/bluetooth.service
'ExecStart=/usr/local/libexec/bluetooth/bluetoothd --experimental'

# reload the configuration and restart the service
sudo systemctl daemon-reload
sudo systemctl restart bluetooth

# reboot
sudo reboot

To enable bluetooth:

# set bluetoothd permission (found [here](https://flows.nodered.org/node/node-red-contrib-generic-ble))
sudo usermod -G bluetooth -a pi
sudo reboot

# start/stop BLE advertising without sudo (found [here](https://flows.nodered.org/node/node-red-contrib-ble-sense))
sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)

# install bluetooth dependencies
sudo apt-get install bluetooth bluez libbluetooth-dev libudev-dev

# check if bluetooth service is active
sudo systemctl status bluetooth
# if not, active it with
sudo systemctl start bluetooth

Bluez Raspberry Problem

Install bleak (in a virtual environment or globally with sudo)
When I run the python script with the bleak test it works only one time

From the second time a get this error

(env) pi@raspberrypi4:~/Desktop/Smart-Apple $ python test-ble.py
Traceback (most recent call last):
  File "/home/pi/Desktop/Smart-Apple/test-ble.py", line 42, in <module>
    asyncio.run(run(address))
  File "/usr/lib/python3.9/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete
    return future.result()
  File "/home/pi/Desktop/Smart-Apple/test-ble.py", line 36, in run
    async with BleakClient(address) as client:
  File "/home/pi/Desktop/Smart-Apple/env/lib/python3.9/site-packages/bleak/__init__.py", line 565, in __aenter__
    await self.connect()
  File "/home/pi/Desktop/Smart-Apple/env/lib/python3.9/site-packages/bleak/__init__.py", line 605, in connect
    return await self._backend.connect(**kwargs)
  File "/home/pi/Desktop/Smart-Apple/env/lib/python3.9/site-packages/bleak/backends/bluezdbus/client.py", line 249, in connect
    assert_reply(reply)
  File "/home/pi/Desktop/Smart-Apple/env/lib/python3.9/site-packages/bleak/backends/bluezdbus/utils.py", line 22, in assert_reply
    raise BleakDBusError(reply.error_name, reply.body)
bleak.exc.BleakDBusError: [org.bluez.Error.Failed] Software caused connection abort

if I create a new virtual environment and run the script it works the first time and then stops working the following times
I tried removing the /var/lib/bluetooth directory but without success
Reinstalling bleak didnt work

Solution

Installing bluepy with libglib fixes the dependencies
```
sudo apt-get install libglib2.0-dev
sudo pip install bluepy
```

PeriniM/SmartApple-Thesis

IoT Sensor System for Fruit Stress Monitoring in Apple Grading Industrial Processes

Operational steps

Option 1 - Only Master

Option 2 - Slave & Master

Raspberry Pi 4 Set-up

Common Set-up

Set-up Modem

Installing OS

Update BLE stack

Disable Wifi Power Management

Dependencies Installation

IoT Gateway

Using External Bluetooth Antenna

Run script on boot

IoT Server

Docker Influxdb, Grafana and Mosquitto

Set datetime

Run script on boot

Extras

Enabling VNC

Install Node-RED

Raspberry Pi Zero W (WORKING)

Install BLE dependencies on Raspberry Pi 3 (NOT WORKING)

Bluez Raspberry Problem

Solution