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Axiom32_w_velocity
// BGW axiom32 keyboard, midi USB with velocity
// http://synthbror.com
// https://github.com/brorgustav/BGW_keyboard/
// free to use
// http://synthbror.com/hacking-the-keyboard-of-m-audio-axiom-32/
#include "BGW_Keyboard.h"
#include "MIDIUSB.h"
#define debug SERIAL_PORT_MONITOR
#define ledPin LED_BUILTIN
#define num_keys 32
const byte numRows = 8; //four rows
const byte numCols = 8; //four columns
// R = Rows C = Columns VC = Columns for velocity (same keys as in columns)
// AXIOM 32 flex cable pinout: R1,R2,R3,R4,R5,R6,R7,R8,C1,VC1,VC2,C2,C3,VC3,C4,VC4
// Mapping in order to matrix adress map((keyboardnote)): R1,R2,R3,R4,R5,R6,R7,R8,C1,C2,C3,C4,VC1,VC2,VC3,VC4
byte keyboardRows[numRows] = {5, 4, 3, 2, 1, 0, 21, 20}; //ROWS of the keyboard, i used mkrzero
byte keyboardCols[numCols] = {6, 9, 10, 12, 7, 8, 11, 13}; //columns
//Hence that with the keyboardNote array and this pin declaration
// i remapped the velocity inputs and placed them as last columns
uint8_t keyboardNote[numRows][numCols] = {
{1, 9, 17, 25, 33, 41, 49, 57},
{2, 10, 18, 26, 34, 42, 50, 58},
{3, 11, 19, 27, 35, 43, 51, 59},
{4, 12, 20, 28, 36, 44, 52, 60},
{5, 13, 21, 29, 37, 45, 53, 61},
{6, 14, 22, 30, 38, 46, 54, 62},
{7, 15, 23, 31, 39, 47, 55, 63},
{8, 16, 24, 32, 40, 48, 56, 64}
};
uint8_t keyOffset = 36 - keyboardNote[0][0]; //Defines what midi note key #1 will be
unsigned long velSensitivity = 800; //This variable defines how sensitive the velocity will be
uint8_t fixedChannel = 0; //The MIDI channel the keyboard maps its notes to
unsigned long keyTimer[num_keys]; //Variable used in measuring the time between velocity column and note column on key pressed
unsigned long loopCount;///variables for testing the speed of code
unsigned long startTime;//variables for testing the speed of code
Keyboard BGW_keyboard = Keyboard( makeKeymap(keyboardNote), keyboardRows, keyboardCols, numRows, numCols);
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
pinMode(LED_BUILTIN, OUTPUT);
loopCount = 0;
startTime = millis();
BGW_keyboard.setDebounceTime(20); //debounce filters out noise on keypresses, to make sure a key has been pressed
BGW_keyboard.setHoldTime(7000); //this defines how long you need to hold down a key before it executes the "hold" state in keypad library
delay(1000);
debug.print("maximum polyphony according to keypad.h (#define LIST_MAX) = ");
debug.println(LIST_MAX);
}
void noteOn(byte channel, byte pitch, byte velocity) {
midiEventPacket_t noteOn = {0x09, 0x90 | channel, pitch, velocity};
MidiUSB.sendMIDI(noteOn);
MidiUSB.flush();
debug.print("[MIDI] NOTE ON:");debug.print(channel);debug.print("|");debug.print(pitch);debug.print("|");debug.print(velocity); debug.println("");
}
void noteOff(byte channel, byte pitch, byte velocity) {
midiEventPacket_t noteOff = {0x08, 0x80 | channel, pitch, velocity};
MidiUSB.sendMIDI(noteOff);
MidiUSB.flush();
debug.print("[MIDI] NOTE OFF:"); debug.print(channel); debug.print("|"); debug.print(pitch); debug.print("|"); debug.print(velocity); debug.println("");
}
void controlChange(byte channel, byte control, byte value) {
midiEventPacket_t event = {0x0B, 0xB0 | channel, control, value};
MidiUSB.sendMIDI(event);
MidiUSB.flush();
}
void loop() {
// put your main code here, to run repeatedly:
// loopCount++;
// if ( (millis() - startTime) > 5000 ) {
// Serial.print("Average loops per second = ");
// Serial.println(loopCount / 5);
// startTime = millis();
// loopCount = 0;
// }
if (BGW_keyboard.getKeys())
{
for (int i = 0; i < LIST_MAX; i++) // Scan the whole key list.
{
if ( BGW_keyboard.key[i].stateChanged ) // Only find keys that have changed state.
{
uint8_t tx = BGW_keyboard.key[i].kchar;
switch (BGW_keyboard.key[i].kstate) { // Report active key state : IDLE, PRESSED, HOLD, or RELEASED
case PRESSED:
{
if (tx > num_keys) //If the key is over the number of keys it is one of the velocity keys
{
keyTimer[tx - num_keys] = millis();
debug.print("[");
debug.print(tx - num_keys);
debug.print("] = ");
debug.println(keyTimer[tx - num_keys]);
}
else { //if not its a "note key"
unsigned long elapsed = millis() - keyTimer[tx];
debug.print("[");
debug.print(tx);
debug.print("] = ") ;
debug.println(elapsed);
uint8_t velocity = log(elapsed + 1) / log(velSensitivity) * 127; //map the velocity timing logarithmically
velocity = map(velocity, 0, 127, 127, 0); //invert the velocity value
velocity = constrain(velocity, 1, 127);
noteOn(fixedChannel, tx + keyOffset, velocity); // Channel 0, middle C, normal velocity
keyTimer[tx] = 0;
}
break;
}
case HOLD:
{
}
break;
case RELEASED:
{
if (tx <= num_keys) //Filter out velocity keys from sending MIDI on release
{
noteOff(fixedChannel, tx + keyOffset, 0);
}
}
break;
case IDLE:
{
}
break;
}
}
}
}
}
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