Although the PYB Nano board is small, it contains all the features of MicroPython. It is an ideal development board for beginners to learn more about MicroPython. It can be a well cost choice for you, for the price is low, but it supports most features and functions of MicroPython. The PYB Nano has accelerometer, the data of sport can be read directly.
It is convenient to extend features via I2C, SPI, UART and other interfaces. By connecting various sensors, LCD displays, OLED, GPS module and so on, you can DIY some interesting projects.