This project is a combination of hardware and software. The project is designed to help save water by measuring shower times and alerting the user when the shower time has been exceeded.
The hardware is based on a STM32 low power microcontroller, which monitors with the help of a Hall and a temperature sensor whether water flows through the hose of a shower. With the help of a RGB LED a signaling for the user takes place. The hardware is managed in a separate repository and can be found here: https://github.com/daestx/showertimer_hw
The software is developed with the help of the STM32cubeIDE. To start the development you just have to download the source code (complete STM32cubeIDE project) and import it into the development environment.