*5.3.4 Wireless communication and data flow*

The final section of experimentation is designed to show students that for any data to be useful it must be provided to an end user who cares about it and it must be presented properly. The system of choice for communication is MQTT 5. This allows for the simplest possible method of publishing the resulting data from the microcontroller for external use (**Figure 17**).

**Figure 17.** *Machine health monitoring data flow.*

An InfluxDB can be used as the receiving database. It is important to display the data to the user and it is also important to store that data. If the data is stored it can later be used for developing machine learning based decisions. The historical data can also be used for long term vibration analysis which is the most important element in preventative maintenance.

This experiment can be extended to have students send the raw sampling data over Wi-Fi. What students will quickly realize (depending on their lab setup) is that

**Figure 18.** *Machine health monitoring station hardware setup.*

it is much more "power expensive" to send raw data over Wi-Fi as compared to processing the data and sending the compressed details.
