Arduino based MIDI channel modifier with LCD display and rotary encoders
I use a Doepfer LMK3 (88 keys) MIDI keyboard which has great features but unfortunately changing MIDI channels is a pain in the a**. The original display and potentiometer are not comfortable to read/use in case you often have to change MIDI channel(s).
So i decided to create a MIDI-IN/MIDI-OUT Arduino (DIN-MIDI and/or USB-MIDI) with 2 rotary+push encoders and an easy to read display.
Further the layer/split features of the Edirol PCR-800 keyboard inspired me to implement an easy to use layer/split functionality as well.
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|J3 J2|
|_ _|
|•| |•|
to Arduino UNO RESET <-|•|LCD_RST |•|
to Arduino UNO A3 <-|•|LCD_CS LCD_02|•|-> to Arduino UNO D2
to Arduino UNO A2 <-|•|LCD_RS LCD_03|•|-> to Arduino UNO D3
to Arduino UNO A1 <-|•|LCD_WR LCD_04|•|-> to Arduino UNO D4
to Arduino UNO A0 <-|•|LCD_RD LCD_05|•|-> to Arduino UNO D5
|¯ LCD_06|•|-> to Arduino UNO D6
|_ LCD_07|•|-> to Arduino UNO D7
|•| ¯|
to Arduino UNO GND <-|•|GND _|
|•| LCD_D0|•|-> to Arduino UNO D8
to Arduino UNO 5V <-|•|5V LCD_01|•|-> to Arduino UNO D9
|•|3V3 SD_SS|•|
|•| SD_DI|•|
|¯ SD_D0|•|
|J4 SD_SCK|•|
| ¯|
| PINS of J1|
| AZ-Delivery |
| 2.4TFT LCD |
|________________________|
MCP23017
_____ _____
| U |
-| 8 7 |- -> to Encoder #1 DT
-| 9 6 |- -> to Encoder #1 CLK
-| 10 5 |- -> to Encoder #1 SW
-| 11 4 |- -> to Encoder #2 DT
-| 12 3 |- -> to Encoder #2 CLK
-| 13 2 |- -> to Encoder #2 SW
-| 14 1 |-
-| 15 0 |-
to Arduino UNO 5V <- -| Vdd INTA |-
to Arduino UNO GND <- -| Vss INTB |-
-| NC RST |- -> to Arduino UNO 5V
to Arduino UNO A5(SCL) <- -| SCL A2 |- -> to Arduino UNO GND
to Arduino UNO A4(SDA) <- -| SDA A1 |- -> to Arduino UNO GND
-| NC A0 |- -> to Arduino UNO GND
|___________|
After powering the device is in bypass mode. All incoming MIDI events will be sent through.
As soon as the left encoder is rotated, the display shows 3 numbers:
- Midi channel to transform to
- Octave shift
- semitone transpose
All incoming midi events will be transformed to the displayed midi channel
By pushing the encoder the rotation action loops through
- Edit midi channel
- Edit octave shift
- edit semitone transpose
As soon as the right encoder is rotated, a 2nd transform section shows up on the display. There are 2 different modes:
SPLIT-Mode: the lower and upper half of the keyboard sends to different midi channels
LAYER-Mode: by pressing an key of your keyboard, the note events gets doubled and sent to 2 different midi channels.
Of course the octave shift and semitone transpose settings gets applied in all 3 modes (single, dual-split, dual-layer)
To disable the 2nd transformation (right part of the display) simply rotate the right encoder anti clockwise to channel 0.
To go back into bypass-mode simply rotate the left encoder anti clockwise to channel 0.
By pressing one of the encoders for one second you can toggle between layer- and split-mode.
By pressing one of the encoders for 5 seconds the device will reboot.