After the first Python-Arduino project, you learned the process of prototyping various sensors, developing user interfaces, and plotting sensor data. The concepts that you learned in the previous chapters can be utilized to create a wide variety of Arduino-based hardware projects. The inception of a good application concept always begins with a real-world necessity and ends up as a practical project if it is executed properly. In this chapter, we will demonstrate this project-building process with an example of a portable sensor unit. As you can estimate from the chapter title, we will be building a simple and portable DIY thermostat that can be deployed without a desktop computer or a laptop.

To begin with, we will describe the proposed thermostat with specific goals and processes to achieve them. Once the strategy to achieve these goals has been laid down, you will be introduced to the two successive programming stages to develop...