Wire up your microcontroller to power and ground according to its circuit diagram. To the circuit you’ll now add the MIDI circuit. For this you’ll need the 2N2222 transistor.

To the circuit you’ll now add the MIDI circuit. For this you’ll need the 2N2222 transistor. Hold the transistor by the legs with the tab facing you, the pinout for the transistor is: C, B, E ...