Arduino sketch for an a 8 x 8 MIDI sequencer based on 4 Adafruit Trellis Keypads and the Adafruit Music Maker Shield / VLSI VS1053b.
The project consists of 4 Trellis Keypads that form an 8x8 matrix for an 8 note, 8 step pattern, and 4 Potentiometers to control the various functions. More information on the hardware setup can be found here (in german).
Check out this video of the sequencer in action
The Sequencer has 4 separate channels that play at the same time, some of them have specific behaviours:
- Channel 1 - Drums: Not effected by pitch changes. Does not use CDEFGAH Note scale, but specific notes defined in the playDrumNote function
- Channel 2 - Bass
- Channel 3 - Pads: The notes are not stopped immediately in the following step, but only when another note is encountered or all notes have been removed
- Channel 4 - Lead
The channel to be shown on the matrix is selected with the first potentiometer.
The second potentiometer sets the play speed via a delay. At its max setting there is no delay. At its minimal setting there is a 512 ms delay.
The third potentiometer sets the octave to use / the pitch. This does not affect the drum channel. It goes from C2 (midi notes 36 - 48) to C6 (midi notes 108 - 120).
Instruments are selected with the fourth potentiometer. All available instruments and their corresponding values can be found on page 32 of this document. Instruments are selected in Groups. Default Assignment is as follows:
| Index | Name | Drums | Bass | Pad | Lead |
|---|---|---|---|---|---|
| 0 | Glockenspiel | Bank 2: Percussion | 38: Slap Bass 2 | 42: Viola | 10: Glockenspiel |
| 1 | Drums | Bank 2: Percussion | 118: Melodic Tom | 114: Agogo | 116: Woodblock |
| 2 | Rock | Bank 2: Percussion | 38: Slap Bass 2 | 19: Rock Organ | 29: Electric Guitar (muted) |
| 3 | Choir | 116: Woodblock | 54: Voice Oohs | 53: Choir Aahs | 86: Voice Lead |
| 4 | Church | 15: Tubular Bells | 53: Choir Aahs | 20: Church Organ | 20: Church Organ |
| 5 | Glitchy | 120: Reverse Cymbal | 121: Guitar Fret Noise | 77: Blown Bottle | 114: Agogo |
| 6 | Electronic | 119: Synth Drum | 87: Fifths Lead | 83: Calliope Lead | 7: Harpsichord |
| 7 | Electronic | 119: Synth Drum | 87: Fifths Lead | 83: Calliope Lead | 7: Harpsichord |
There are two alternative Sketches for this hardware setup. The first one runs the Game of Life on the matrix display and can be found in the 'GameOfLife' folder. The second one, which can be found in the folder 'MIDIControll', sends MIDI notes to an external source and runs the sequencer based on an external MIDI clock signal. It requires a MIDI <> Serial bridge like Hairless MIDI Serial.