How an inexpensive, pocket size, battery powered altimeter can help provide a lot of fund, as well as pilot currency. Its based on the Arduino Uno R3, a 2.8 inch ILI9341-based TFT LCD touch screen shield designed to plug directly into the header pins of the Arduino Uno, and the BMP 280 Bosch sensor (5V compatible version only) as sold by various suppliers, such as Adafruit. The Arduino software to drive it is available under the Creative Commons License, free of charge, at GitHub, at https://github.com/kenburrell/PracticeAltimeter