This project is a great example of how to hack a kitchen scale into a tool for making drinks with an Android application. You can use the code from this project as an example of how to communicate between an Android device and an Arduino through a USB or bluetooth connection.

Some interesting ways you can extend the project are:

• Add your own drink recipes by modifying the drinks.json file and rebuilding the application. Look at the existing drinks to see the schema for documenting drink preparation steps.
• Use a higher precision analog to digital converter, like this 16-bit ADC, to measure much smaller weights from the load cell. Perhaps you can even build a smart measuring cup to simplify tasks in the kitchen like baking cookies!
• Add an audible warning to the application when nearing the target measurement for a preparation step.
• Try switching the application to use a SQLite database to store a huge number of drink recipes. Look at normalizing the grams_per_oz for each preparation step into a separate table based on each ingredient type.
• Use an Android device to add a great interface to your own Arduino project!