How to read from sqlite3 database to create mobile dashboard?

To meet the requirement where a Windows application writes sensor data into a SQLite database and an Android tablet needs to be notified of new data and display it graphically, there are several possible approaches.

Since SQLite is serverless, it is not well-suited for parallel access from multiple devices (such as Windows and Android). A centralized database system (like MySQL or PostgreSQL) would be a better option, as these are designed to handle concurrent access from different devices. If it is possible to modify the legacy program that writes sensor data into the SQLite database, this would be the best and most sustainable long-term solution.

If the legacy program does not use transactions, SQLite is not ideal for parallel access, since it only allows one write operation at a time. However, if all access were to occur within transactions, concurrent read access could happen without conflicts, with only one write operation allowed at a time.

If the legacy program cannot be modified and does not already use transactions, migrating to another database system could be challenging. An alternative would be to monitor the SQLite database file. Once a change is detected, another program could place a shared lock (which SQLite supports by default), allowing multiple programs to read simultaneously while blocking write operations. The reaction of the legacy program to a locked SQLite database depends on its implementation. If the lock does not last too long, this could be a workable solution.

The program that monitors the database could notify the Android tablet when data changes and send the necessary data. This could be done directly or by buffering the data via a web server. A possible implementation could be done relatively easily using Python.