Multi Connectivity: Half-Duplex

This project is part of the proof of concept Multi Connectivity. The purpose of this project is to validate new DAB+ messages. With the contained data an acknowledgement needs to be send back with the use of multiple wireless connections. For more information read the thesis (500770588-Afstudeerrapport-final.docx) on the OneDrive.

This application interfaces with dab-receiver, cap-dab-server and cfns-webapp. See the diagram below.

Features

Following features are provided

• Read provided devices and settings from devices.csv
• Observe folder for identifying new DAB+ message
• Read content of DAB+ message
• Sending acknowledgement by AIS, LoRaWAN and LTE, WiFi
• Supported interfaces: UART, I2C, Socket and SPI
• Share information from DAB+ messages on request using an interface
• Select the best technology to acknowledge DAB+ messages

Requirements

Libraries

• Watchdog
• aisutils
• argparse
• csv

Hardware

• Raspberry Pi 4B
• True Heading AIS Class A Base Station
• Sodaq One Rev3
• Pycom FiPy

Setups

In order for the system being able to acknowledge DAB+ messages using the supported hardware and technologies you need to set them up first. The following section will guide you setting up the different technologies for the different hardware.

Wifi Setup

1. Follow the setup for the server in the repository: Wifi6_confirmation_server.
2. Follow the setup for WiFi in the repository: cfns-hd-fipy.
3. Make sure that devices.csv contains the following at the first line:

name,branch,model,interface_type,address,setting,technology,priority

3. If you want to only use WiFi remove everything from the file except for the first line. After that add the following to the file directly below the first line:

FiPy,Pycom,FiPy,2,192.168.178.11,8000,Wifi,1

4. If you want to add WiFi to the list of technologies the system can use. Add the line shown above directly below the other files. Also make sure that the other devices/technologies are supported and described properly.
5. In this example the IP-adres of the server running on the FiPy is: 192.168.178.11 and port 8000. Check this with the socket information you use. This information can be found in the file Server.py in the repository: cfns-hd-fipy.
6. If nothing went wrong you have succesfully set up WiFi on the FiPy.

LoRaWAN (FiPy) Setup

1. Follow the setup for LoRaWAN in the repository: cfns-hd-fipy.
2. Make sure that devices.csv contains the following at the first line:

name,branch,model,interface_type,address,setting,technology,priority

3. If you want to only use LoRaWAN remove everything from the file except for the first line. After that add the following to the file directly below the first line:

FiPy,Pycom,FiPy,2,192.168.178.11,8000,LoRa,2

4. If you want to add LoRaWAN to the list of technologies the system can use. Add the line shown above directly below the other files. Also make sure that the other devices/technologies are supported and described properly.
5. In this example the IP-adres of the server running on the FiPy is: 192.168.178.11 and port 8000. Check this with the socket information you use. This information can be found in the file Server.py in the repository: cfns-hd-fipy.
6. If nothing went wrong you have succesfully set up LoRaWAN on the FiPy.

LoRaWAN (Sodaq One) Setup

1. Follow the setup for LoRaWAN in the repository: cfns-hd-so.
2. Make sure that devices.csv contains the following at the first line:

name,branch,model,interface_type,address,setting,technology,priority

3. If you want to only use LoRaWAN remove everything from the file except for the first line. After that add the following to the file directly below the first line:

LoRaWANTransponder,SODAQ,Sodaq One,1, 4,,LoRa,3

4. If you want to add LTE to the list of technologies the system can use. Add the line shown above directly below the other files. Also make sure that the other devices/technologies are supported and described properly. It is correct that there are two comma's between 4 and LoRa.
5. In this example the I2C address is 4 change this to the I2C address the Sodaq One uses in your setup.
6. To change the I2C address change line 179 of Half-Duplex_SodaqOne.ino which can be found in the repository: cfns-hd-so and in devices.csv at step 3 of this guide.

LTE (CAT-M1) Setup

1. Follow the setup for LTE in the repository: cfns-hd-fipy.
2. Make sure that devices.csv contains the following at the first line:

name,branch,model,interface_type,address,setting,technology,priority

3. If you want to only use LoRaWAN remove everything from the file except for the first line. After that add the following to the file directly below the first line:

FiPy,Pycom,FiPy,2,192.168.178.11,8000,LTE,4

4. If you want to add LTE to the list of technologies the system can use. Add the line shown above directly below the other files. Also make sure that the other devices/technologies are supported and described properly.
5. In this example the IP-adres of the server running on the FiPy is: 192.168.178.11 and port 8000. Check this with the socket information you use. This information can be found in the file Server.py in the repository: cfns-hd-fipy.
6. If nothing went wrong you have succesfully set up LTE on the FiPy.

AIS Setup

1. Connect The True Heading AIS Base Station to the Raspberry Pi by USB.
2. Make sure that devices.csv contains the following at the first line:

name,branch,model,interface_type,address,setting,technology,priority

3. If you want to only use AIS remove everything from the file except for the first line. After that add the following to the file directly below the first line:

AIS Base Station,True Heading,Carbon Pro,0,/dev/ttyACM0,38400,AIS,0

4. If you want to add AIS to the list of technologies the system can use. Add the line shown above directly below the other files. Also make sure that the other devices/technologies are supported and described properly.
5. Furthermore make sure that /dev/ttyACM0 is being used by the FiPy for the AIS device.
6. To check this unplug the Base Station from the Raspberry Pi and run the following command on the Raspberry Pi:

ls /dev/tty*

7. Plug the Base Station back in and rerun the command. Then see which /dev/tty was added and that is the USB port the Base Station uses.
8. Use that /dev/tty in devices.csv.
9. You have succesfully setup AIS.

DAB+ File Format

When a DAB+ message is received it will be stored as a .txt file in the folder correct. To simulate a message coming in a file can be made and put in that folder. The file needs to contain the following in order:

• DAB id.
• Message type.
• Category.
• X coordinate
• Y coordinate
• other data

The DAB id must be a positive integer and it is used to distinguish the different message from each other. The message type must also be an integer but it must be between 1 and 4 with both those numbers included to have a function. Some technologies support different types of acknowledgment. To figure out what message type to use see the files for the corresponding device/technology. Then you must specify the category for the different options see Category.py. If the the category is location you must specify an X and Y coordinate otherwise you can leave these lines empty. The rest of the lines can you be used for other data such as the CAP message if the category is CAP.

Acknowledging a DAB+ message

1. First, follow the setup of the technologies you want to the system to use for acknowledging DAB+ message (see [Setups](## Setups). You can add technologies later even when the system is running as long as you follow the corresponding setup(s).
2. Run main.py with the following command on the Raspberry Pi:

python3 main.py ./devices.csv ./correct

3. Either send a DAB+ message to the Raspberry Pi or simulate a message coming in. To simulate a DAB+ message coming in add a .txt file in correct according to the format specified in [DAB+ File Format](## DAB+ File Format).
4. Watchdog observer detects a new DAB+ message and reads the content.
5. The system starts the acknowledgment process by choosing the best technology available at that moment.
6. The system will send the acknowledgment information the device that will acknowledge the DAB+ message using the chosen technology.
7. The chosen hardware will send the acknowlegdment
8. If the technology is not AIS the device will let the system onboard know the acknowledgment is succeeded or not.
9. Finally the system will update the status of the file.

Requesting data from the system using the interface

In order for the interface to the onboard systems in this section specified as the interface to work the minimal requirement is for the system to be running. The interface will only start if the rest of the system is started as well.

Testing if client and interface work

This section explains you how to test if the interface and the client are functioning properly.

1. Turn on the system by running the following command on the Raspberry Pi in this case devices.csv can contain only the required first line:

python3 main.py ./devices.csv ./correct

2. Open client_template.py and make sure the socket information specified in the client.connect statement contains the socket information that corresponds to the socket information of the interface runs on.
3. Check if the client and the interface are on the same network.
4. Make sure the message looks as followed:

message = json.dumps({"request_type": "test"}).encode()

5. If everything checks out, run the client_template.py script. Either on the Raspberry Pi itself or another device on the same network that has python installed.
6. The client will request the test data from the interface of the system and display it on the screen. If the result looks the same as in the method build_information_dict of class TestRequest in Request.py

How to request data

To request other types of data then the test data follow the process specified above. Only instead of using the message shown in step 4 use the following message to get all the data that you have not requested:

message = json.dumps({"request_type": "latest"}).encode()

To request the data of a specific category use the following message:

message = json.dumps({"request_type": "by_category","category": "other"}).encode()

The valid options are specified in Category.py and can be specified in the place of other.

Finally to request the test data you can use the message described in step 4 of [Testing if client and interface work](### Testing if client and interface work).

Credit

Credit to Kurt Schwehr and Google for AISutils.