his design is a 26-way MIDI/USB drum pad system with the velocity byte fixed for 10 input drum switches and a 16-way velocity sensitive circuit, providing a full (0-127) velocity range using piezo sensors. The drums are pre-selected to the MIDI outputs 35-50 for the piezos and 51-60 for the switches. The MIDI drum selections are available for General MIDI drums.

26-Way MIDI DRUMS schemetic

It provides MIDI data which has to be sent to a drum/synthesiser or sound module. The velocity byte is dependent on how hard the piezo transducer is hit.  The drum choices, and the MIDI transmit channel are assigned in the  program. However, normally the drum sounds are assigned to MIDI channel 10.

The 26-Way drum inputs to MIDI Output unit utilizes:

  • An Arduino Mega board including a suitable pre-programmed Atmega microcontroller,
  • A 2.1mm power socket, and associated LED,
  • 16 inputs are velocity sensitive, providing a full (0-127) velocity range,
  • 10 inputs for momentary action switches, giving a fixed velocity output,
  • A MIDI 5-pin DIN output socket,
  • Each input (1-26) is pre-selectable on programming to a particular MIDI drum selection ,


The 26-Way drum inputs to MIDI Output unit requires:

  • A 9v battery or equivalent DC power source,
  • The circuit consists of the MIDI drum interface.
  • Suitable external 16 piezo-electric transducers,
  • 32 off 1M Ohm resistors
  • 16 off IN4148 diodes,
  • 16 off 100 nF capacitors,
  • Suitable 10 push-to-make switches

Circuit Schematic:

circuit schematic of the MIDI drum interface shows the Input/Output connections. The circuit schematic for the Arduino MEGA is also available.

NOTE: Any unused analog inputs should be connected to ground (GND) otherwise they will pick up noise and produce spurious outputs.


The MIDI OUT connection uses 5-Pin 180 degree DIN sockets. Note that the MIDI Out socket is polarised and the correct pins should be used. The MIDI output is set to MIDI Channel 10, which is the standard MIDI drum channel. This unit can work in standard MIDI mode, at a MIDI Baud rate of 31250.


For more detail: 26-Way MIDI DRUMS

About The Author

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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