update main uClock README.md to reflect the changes on 303 step sequencer engine.

README.md

@@ -22,6 +22,60 @@ Here a few examples on the usage of Clock library for MIDI devices, keep in mind
 
 If you dont want to build a MIDI interface and you are going to use your arduino only with your PC, you can use a Serial-to-Midi bridge and connects your arduino via USB cable to your conputer to use it as a MIDI tool [like this one](http://projectgus.github.io/hairless-midiserial/).
 
+### A Simple MIDI Sync Box sketch example
+Here is a example on how to create a simple MIDI Sync Box
+
+```c++
+#include <uClock.h>
+
+// MIDI clock, start and stop byte definitions - based on MIDI 1.0 Standards.
+#define MIDI_CLOCK 0xF8
+#define MIDI_START 0xFA
+#define MIDI_STOP  0xFC
+
+// The callback function wich will be called by Clock each Pulse of 96PPQN clock resolution.
+void ClockOut96PPQN(uint32_t * tick) {
+  // Send MIDI_CLOCK to external gears
+  Serial.write(MIDI_CLOCK);
+}
+
+// The callback function wich will be called when clock starts by using Clock.start() method.
+void onClockStart() {
+  Serial.write(MIDI_START);
+}
+
+// The callback function wich will be called when clock stops by using Clock.stop() method.
+void onClockStop() {
+  Serial.write(MIDI_STOP);
+}
+
+void setup() {
+
+  // Initialize serial communication at 31250 bits per second, the default MIDI serial speed communication:
+  Serial.begin(31250);
+
+  // Inits the clock
+  uClock.init();
+  // Set the callback function for the clock output to send MIDI Sync message.
+  uClock.setClock96PPQNOutput(ClockOut96PPQN);
+  // Set the callback function for MIDI Start and Stop messages.
+  uClock.setOnClockStartOutput(onClockStart);  
+  uClock.setOnClockStopOutput(onClockStop);
+  // Set the clock BPM to 126 BPM
+  uClock.setTempo(126);
+
+  // Starts the clock, tick-tac-tick-tac...
+  uClock.start();
+
+}
+
+// Do it whatever to interface with Clock.stop(), Clock.start(), Clock.setTempo() and integrate your environment...
+void loop() {
+
+}
+```
+
+
 ### Acid Step Sequencer
 
 A clone of Roland TB303 step sequencer main engine, here is a example with no user interface for interaction. If you're looking for a user interactable TB303 sequencer engine clone with user interface please take a look here https://github.com/midilab/uClock/tree/development/examples/AcidStepSequencer.
@@ -34,11 +88,14 @@ A clone of Roland TB303 step sequencer main engine, here is a example with no us
 
 // Sequencer config
 #define STEP_MAX_SIZE      16
+#define SEQUENCER_MIN_BPM  50
+#define SEQUENCER_MAX_BPM  177
 #define NOTE_LENGTH        4 // min: 1 max: 5 DO NOT EDIT BEYOND!!!
 #define NOTE_VELOCITY      90
 #define ACCENT_VELOCITY    127
+#define NOTE_STACK_SIZE    3 // 1 for no glide note, other 2 for overlap glide notes
 
-// MIDI modes
+// MIDI config
 #define MIDI_CHANNEL      0 // 0 = channel 1
 
 // Sequencer data
@@ -58,10 +115,10 @@ typedef struct
   int8_t length;
 } STACK_NOTE_DATA;
 
-STACK_NOTE_DATA _note_stack[2];
+STACK_NOTE_DATA _note_stack[NOTE_STACK_SIZE];
 
 bool _playing = false;
-uint16_t _step = 0;
+uint16_t _step, _step_edit = 0;
 uint16_t _step_length = STEP_MAX_SIZE;
 
 // MIDI clock, start, stop, note on and note off byte definitions - based on MIDI 1.0 Standards.
@@ -84,33 +141,37 @@ void sendMidiMessage(uint8_t command, uint8_t byte1, uint8_t byte2)
 // Each call represents exactly one step here.
 void ClockOut16PPQN(uint32_t * tick) 
 {
-  uint16_t step;
+  uint16_t step, length;
-  bool glide_ahead;
   
   // get actual step.
   _step = *tick % _step_length;
   
   // send note on only if this step are not in rest mode
   if ( _sequencer[_step].rest == false ) {
+    // send note on
     sendMidiMessage(NOTE_ON, _sequencer[_step].note, _sequencer[_step].accent ? ACCENT_VELOCITY : NOTE_VELOCITY);
-    // do we have a glide ahead us?
+    
+    // check for glide event ahead of _step
     step = _step;
     for ( uint16_t i = 1; i < _step_length; i++  ) {
       ++step;
       step = step % _step_length;
       if ( _sequencer[step].glide == true && _sequencer[step].rest == false ) {
-        _note_stack[1].note = _sequencer[_step].note;
+        length = NOTE_LENGTH + (i * 6);
-        _note_stack[1].length = NOTE_LENGTH + (i * 6);
-        glide_ahead = true;
         break;
       } else if ( _sequencer[step].rest == false ) {
-        glide_ahead = false;
+        length = NOTE_LENGTH;
         break;
       }
     }
-    if ( glide_ahead == false ) {
+
-      _note_stack[0].note = _sequencer[_step].note;
+    // find a free note stack to fit in
-      _note_stack[0].length = NOTE_LENGTH;
+    for ( uint8_t i = 0; i < NOTE_STACK_SIZE; i++ ) {
+      if ( _note_stack[i].length == -1 ) {
+        _note_stack[i].note = _sequencer[_step].note;
+        _note_stack[i].length = length;
+        return;
+      }
     }
   }  
 }
@@ -122,20 +183,13 @@ void ClockOut96PPQN(uint32_t * tick)
   Serial.write(MIDI_CLOCK);
 
   // handle note on stack
-  // [1] is notes to be glided, its in hold on mode until we reach the glided step
+  for ( uint8_t i = 0; i < NOTE_STACK_SIZE; i++ ) {
-  if ( _note_stack[1].length != -1 ) {
+    if ( _note_stack[i].length != -1 ) {
-    --_note_stack[1].length;
+      --_note_stack[i].length;
-    if ( _note_stack[1].length == 0 ) {
+      if ( _note_stack[i].length == 0 ) {
-      sendMidiMessage(NOTE_OFF, _note_stack[1].note, 0);
+        sendMidiMessage(NOTE_OFF, _note_stack[i].note, 0);
-      _note_stack[1].length = -1;
+        _note_stack[i].length = -1;
-    }
       }
-  // [0] is the actual step note stack
-  if ( _note_stack[0].length != -1 ) {
-    --_note_stack[0].length;
-    if ( _note_stack[0].length == 0 ) {
-      sendMidiMessage(NOTE_OFF, _note_stack[0].note, 0);
-      _note_stack[0].length = -1;
     }  
   }
 }
@@ -144,14 +198,18 @@ void ClockOut96PPQN(uint32_t * tick)
 void onClockStart() 
 {
   Serial.write(MIDI_START);
+  _playing = true;
 }
 
 // The callback function wich will be called when clock stops by using Clock.stop() method.
 void onClockStop() 
 {
   Serial.write(MIDI_STOP);
-  sendMidiMessage(NOTE_OFF, _note_stack[1].note, 0);
+  for ( uint8_t i = 0; i < NOTE_STACK_SIZE; i++ ) {
-  sendMidiMessage(NOTE_OFF, _note_stack[0].note, 0);
+    sendMidiMessage(NOTE_OFF, _note_stack[i].note, 0);
+    _note_stack[i].length = -1;
+  }
+  _playing = false;
 }
 
 void setup() 
@@ -184,71 +242,25 @@ void setup()
     _sequencer[i].rest = false;
   }
 
-  // starts the sequencer
+  // initing note stack data
-  uClock.start();
+  for ( uint8_t i = 0; i < NOTE_STACK_SIZE; i++ ) {
+    _note_stack[i].note = 0;
+    _note_stack[i].length = -1;
+  }
 
   // pins, buttons, leds and pots config
   //configureYourUserInterface();
+  
+  // start sequencer
+  uClock.start();
 }
 
 // User interaction goes here
 void loop() 
 {
+  // Controls your 303 engine interacting with user here...
   //processYourButtons();
   //processYourLeds();
   //processYourPots();
 }
 ```
-
-### A Simple MIDI Sync Box sketch example
-Here is a example on how to create a simple MIDI Sync Box
-
-```c++
-#include <uClock.h>
-
-// MIDI clock, start and stop byte definitions - based on MIDI 1.0 Standards.
-#define MIDI_CLOCK 0xF8
-#define MIDI_START 0xFA
-#define MIDI_STOP  0xFC
-
-// The callback function wich will be called by Clock each Pulse of 96PPQN clock resolution.
-void ClockOut96PPQN(uint32_t * tick) {
-  // Send MIDI_CLOCK to external gears
-  Serial.write(MIDI_CLOCK);
-}
-
-// The callback function wich will be called when clock starts by using Clock.start() method.
-void onClockStart() {
-  Serial.write(MIDI_START);
-}
-
-// The callback function wich will be called when clock stops by using Clock.stop() method.
-void onClockStop() {
-  Serial.write(MIDI_STOP);
-}
-
-void setup() {
-
-  // Initialize serial communication at 31250 bits per second, the default MIDI serial speed communication:
-  Serial.begin(31250);
-
-  // Inits the clock
-  uClock.init();
-  // Set the callback function for the clock output to send MIDI Sync message.
-  uClock.setClock96PPQNOutput(ClockOut96PPQN);
-  // Set the callback function for MIDI Start and Stop messages.
-  uClock.setOnClockStartOutput(onClockStart);  
-  uClock.setOnClockStopOutput(onClockStop);
-  // Set the clock BPM to 126 BPM
-  uClock.setTempo(126);
-
-  // Starts the clock, tick-tac-tick-tac...
-  uClock.start();
-
-}
-
-// Do it whatever to interface with Clock.stop(), Clock.start(), Clock.setTempo() and integrate your environment...
-void loop() {
-
-}
-```