I´m currently working in a project that consist of making a dashboard using c# as backend language. The matter to be resolved is how can I create dynimic plots in real time with c#. The other matter is how do I communicate c# with the sensors, until now I have found that exists a protocol called MQTT. I have to use ASP.NET
I have searched that exists a nuget package (MQTTnet) that allows the communication between the broker and c# using the MQTT protocol.
My answer will be as much general as your question is, but since you are asking about a system that allows to visualize gathered sensor data through a real-time dashboard (deployed as a web app) I suggest you to take a look at ASP.NET Core SignalR with Blazor Server Side. This allows you to build a web application in which a client can receive real-time updates using the SignalR protocol. You can use libraries such as Blazor-ApexCharts in order to render charts on the front-end.
You can use MQTTnet in order to subscribe to your MQTT broker and receive sensor data. Then you can push data regularly to the clients, which will update their charts everytime new data is received.
Hope this helps.