The new card gives MIDI Shield Arduino MIDI communication protocol, which is still widely used to control synthesizers, sequencers, and other musical devices. Arduino use the UART pins to send and receive MIDI events.
The MIDI Shield card provides a MIDI-IN opto-isolated port and a MIDI-OUT port. It can be mounted directly on top of an Arduino, connecting the MIDI-IN with the RX pin of the Arduino hardware and MIDI-OUT with pin TX.
Also included are two potentiometers that are connected to the analog pins 1 and 2, which can be used to control volume, tone, or anything else that you would like to change. Also included are three momentary buttons (connected to D2, D3, D4), a reset button and LEDs green and red.
The RUN / PROG switch to program the Arduino without having to remove the MIDI Shield card.
This revision of the SparkFun MIDI Shield also adds several configurable features, such as converting the MIDI output to a MIDI thru, and the option to use a software serial port for MIDI, leaving the hardware serial for programming and debugging. It also buffers the output, making it compatible with the Arduino Pro without needing to circumvent the protection resistors on the serial TX and RX lines.
Note: All components (2 MIDI connectors, 2 faders and 3 buttons) are included with the product, however, is not soldered to the board. It is because of this that the client is who should weld these components.