Now with MIDI arpeggiator!

The v2.1 boards are in and soldered! The new v2.1a firmware is up on github!

Clearing out all v2.0 boards to make room for the new v2.1 boards! The v2.0 boards are exactly the same as the v2.1 boards, with some minor changes to the PCB routing. Send an email to billsmaldon@gmail.com for a $10 off discount code on the remaining v2.0 boards. Please only ask for this code if ordering a v2.0 board!

UPDATE:

NEW v2.1a firmware for 2024!

What's new in the v2.1a firmware:

1) Turn cc while arpeggio ON

While an arpeggio is playing, turning a continuous controller caused stuck Note On messages. This has been fixed.

2) Un-block the code

When in the menu, pressing a key or turning a continuous controller was "blocked", meaning that the keyboard or potentiometers do nothing until the menu item currently being selected was set by clicking the encoder. Now, anywhere in the menu selection key presses and potentiometer turns will work.

3) Change keyboard mode while a key is held

If a key is held and the KEYBOARD MODE is changed, it waits for the key release and then changes the KEYBOARD MODE.

4) Digit brightness

Now the 7 segment digital display has a consistent brightness and is updated at 100 Hz. The only exception is when ARPEGGIO is ON. There is some display flicker while an arpeggio is playing due to the increased CPU load on the microcontroller. Releasing the arpeggio eliminates any flicker in the display.

5) Noisy potentiometers

Potentiometers sometimes sent random control changes when no continuous controller was being turned. This has been fixed.

2023:

With the new v2.1 boards there is also a new firmware update. This new firmware is up on the project github, and flashed into all new boards for sale as of now. Flashed PIC microcontrollers will be available soon for sale for any prior customers (will be contacted by email).

1) Firmware can be compiled for any PCB version

The latest firmware versions are v1.0a/v2.0a. The firmware can now be compiled for any board version. There should be 2 versions of the machine code (.HEX) on the project github, for v1.0 or v2.0 & v2.1 boards.

2) 7 segment display flicker fixed

Low display brightness and visible flicker have been fixed and the display is refreshed at 100 Hz.

3) Potentiometer latency can be adjusted and saved to EEPROM.

If there is too much latency to the potentiometers, the potentiometer “alpha” (which selects how smooth/responsive the potentiometer input is) can be adjusted.

4) Rotary encoder polarity can be changed and saved to EEPROM

The polarity of the rotary encoder used to navigate the user interface (to the right of the LCD) can vary by supplier. If you are turning your encoder clockwise, and the LCD is stuck at “KEYBOARD MODE:”, you might have an encoder with different polarity. See the manual for instructions on how to change this setting.

5) Pentatonic Major and Pentatonic Minor scales have been added

The Pentatonic Major and Pentatonic Minor scales have been added to the KEYBOARD MODE menu.

6) Quick transpose allows you to instantly change keys

A new way of transposing the keyboard has been added to the firmware. Holding the “modifier” button (S28) and pressing any key on the keyboard will instantly transpose by the key that is pressed

7) MIDI Arpeggiator (this is the main focus of the updated firmware)

Here I will briefly describe the features of the new MIDI arpeggiator firmware update.

The MIDI arpeggiator is a 48 PPQN arpeggiator with an internal clock.

It has a tempo range of 25-250 BPM and a maximum octave range of 4.

Available arpeggio types are UP, DOWN, UP/DOWN, DOWN/UP, SHUFFLE (random non-repeating), RANDOM and AS PRESSED.

It has a note length varying from 1/4 note to 1/32 note, with dotted and triplet note types for every note length.

There is a LATCH setting to hold notes after they are released.

Full and detailed instructions are in the manual.

MIDI Controller Specifications:

• 2 octave polyphonic keyboard
• 8 drum buttons (programmable to transmit a MIDI CC or Note Number)
• 7 high quality Bourns conductive plastic potentiometers
• 7 slide potentiometers (Bourns PTA series)
• on-board thumbstick for pitch bend, modulation or assignable to any midi control change number
• 2 external ports for a full sized joystick or any other type of resistive (voltage divider) input
• octave up/down buttons
• modifier button to transpose by semitone when pressing octave up/down
• LCD with rotary encoder to navigate the user interface
• 4 digit seven segment display for the continuous controller values, octave +/- or transpose by semitone
• An actual 5 pin DIN connector to plug into synths or VSTs on PC with a USB to MIDI adapter
• powered by an inexpensive switch mode adapter
• "Advanced keyboard modes" which are basically a lot of music theory programmed into the microcontroller's firmware that make playing in a key, automatically generating chords, scales and modes easy

Specifications (V2.0/V2.1 PCB):

• MIDI over USB (works in Windows, MacOS, Linux)
• USB power (no 5V adapter needed)

Why did you make it?

While learning music theory and researching a few different DAWs, I decided I needed to get a MIDI controller.

I took a look at some basic 2-4 octave controllers on the local music store's website. Seemed useful enough, until the challenge of making my own overwhelmed the convenience of buying and unboxing a store-bought one.

I made a one octave controller on a breadboard and started developing a firmware. I realized I could program into the firmware a lot of the chord/scale/key signature stuff I was learning.

Switching over to EasyEDA, now I was able to design a larger card than was possible on the free version of Eagle. The CAD and firmware are complete!

The "Advanced Keyboard Modes" automatically generate keys, scales, modes and chords including diatonic triads and seventh chords.