An experimental board is a set of boards used for experimenting with various devices. There are many study aids that make it suitable for users of all levels. There is also a set of spare parts to try.
15-PROGRAM NodeMCU BEGINNER EXPERIMENT BOARD
15-PROGRAM ARDUINO NANO ELEMENTARY EXPERIMENT BOARD
16-PROGRAM ARDUINO NANO BEGINNER EXPERIMENT BOARD
UNO INTERMEDIATE STARTER KIT
UNO ELEMENTARY STARTER KIT
UNO BEGINNER STARTER KIT