Initial commit for MIDI user interface button support.

Status: first successful build.

src/Makefile

@@ -9,7 +9,7 @@ CMSIS_DIR = ../CMSIS_5/CMSIS
 OBJS = main.o kernel.o minidexed.o config.o userinterface.o uimenu.o \
        mididevice.o midikeyboard.o serialmididevice.o pckeyboard.o \
        sysexfileloader.o performanceconfig.o perftimer.o \
-       effect_compressor.o effect_platervbstereo.o uibuttons.o
+       effect_compressor.o effect_platervbstereo.o uibuttons.o midipin.o
 
 OPTIMIZE = -O3
 

src/config.cpp

@@ -104,6 +104,13 @@ void CConfig::Load (void)
 	m_nDoubleClickTimeout = m_Properties.GetNumber ("DoubleClickTimeout", 400);
 	m_nLongPressTimeout = m_Properties.GetNumber ("LongPressTimeout", 600);
 
+	m_nMIDIButtonCh = m_Properties.GetNumber ("MIDIButtonCh", 255);
+	m_nMIDIButtonPrev = m_Properties.GetNumber ("MIDIButtonPrev", 0);
+	m_nMIDIButtonNext = m_Properties.GetNumber ("MIDIButtonNext", 0);
+	m_nMIDIButtonBack = m_Properties.GetNumber ("MIDIButtonBack", 0);
+	m_nMIDIButtonSelect = m_Properties.GetNumber ("MIDIButtonSelect", 0);
+	m_nMIDIButtonHome = m_Properties.GetNumber ("MIDIButtonHome", 0);
+
 	m_bEncoderEnabled = m_Properties.GetNumber ("EncoderEnabled", 0) != 0;
 	m_nEncoderPinClock = m_Properties.GetNumber ("EncoderPinClock", 10);
 	m_nEncoderPinData = m_Properties.GetNumber ("EncoderPinData", 9);
@@ -293,6 +300,36 @@ unsigned CConfig::GetLongPressTimeout (void) const
 	return m_nLongPressTimeout;
 }
 
+unsigned CConfig::GetMIDIButtonCh (void) const
+{
+	return m_nMIDIButtonCh;
+}
+
+unsigned CConfig::GetMIDIButtonPrev (void) const
+{
+	return m_nMIDIButtonPrev;
+}
+
+unsigned CConfig::GetMIDIButtonNext (void) const
+{
+	return m_nMIDIButtonNext;
+}
+
+unsigned CConfig::GetMIDIButtonBack (void) const
+{
+	return m_nMIDIButtonBack;
+}
+
+unsigned CConfig::GetMIDIButtonSelect (void) const
+{
+	return m_nMIDIButtonSelect;
+}
+
+unsigned CConfig::GetMIDIButtonHome (void) const
+{
+	return m_nMIDIButtonHome;
+}
+
 bool CConfig::GetEncoderEnabled (void) const
 {
 	return m_bEncoderEnabled;

src/config.h

@@ -117,6 +117,14 @@ public:
 	unsigned GetDoubleClickTimeout (void) const;
 	unsigned GetLongPressTimeout (void) const;
 
+	// MIDI Button Navigation
+	unsigned GetMIDIButtonCh   (void) const;
+	unsigned GetMIDIButtonPrev (void) const;
+	unsigned GetMIDIButtonNext (void) const;
+	unsigned GetMIDIButtonBack (void) const;
+	unsigned GetMIDIButtonSelect (void) const;
+	unsigned GetMIDIButtonHome (void) const;
+	
 	// KY-040 Rotary Encoder
 	// GPIO pin numbers are chip numbers, not header positions
 	bool GetEncoderEnabled (void) const;
@@ -177,6 +185,13 @@ private:
 	unsigned m_nDoubleClickTimeout;
 	unsigned m_nLongPressTimeout;
 
+	unsigned m_nMIDIButtonCh;
+	unsigned m_nMIDIButtonPrev;
+	unsigned m_nMIDIButtonNext;
+	unsigned m_nMIDIButtonBack;
+	unsigned m_nMIDIButtonSelect;
+	unsigned m_nMIDIButtonHome;
+
 	bool m_bEncoderEnabled;
 	unsigned m_nEncoderPinClock;
 	unsigned m_nEncoderPinData;

src/mididevice.cpp

@@ -27,6 +27,7 @@
 #include "config.h"
 #include <stdio.h>
 #include <assert.h>
+#include "userinterface.h"
 
 LOGMODULE ("mididevice");
 
@@ -181,6 +182,19 @@ void CMIDIDevice::MIDIMessageHandler (const u8 *pMessage, size_t nLength, unsign
 	}
 	else
 	{
+		// Perform any MiniDexed level MIDI handling before specific Tone Generators
+		switch (ucType)
+		{
+		case MIDI_CONTROL_CHANGE:
+			if (nLength < 3)
+			{
+				break;
+			}
+			CUserInterface::UIMIDICCHandler (ucChannel, pMessage[1], pMessage[2]);
+			break;
+		}
+
+		// Process MIDI for each Tone Generator
 		for (unsigned nTG = 0; nTG < CConfig::ToneGenerators; nTG++)
 		{
 			if (ucStatus == MIDI_SYSTEM_EXCLUSIVE_BEGIN)

src/midipin.cpp

@@ -0,0 +1,55 @@
+//
+// midipin.cpp
+//
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+#include "midipin.h"
+#include <circle/logger.h>
+#include <assert.h>
+
+LOGMODULE ("midipin");
+
+CMIDIPin::CMIDIPin (unsigned nPinNumber)
+:	m_nPinNumber (nPinNumber),
+	m_nValue (HIGH)
+{
+}
+
+CMIDIPin::~CMIDIPin (void)
+{
+}
+		
+unsigned CMIDIPin::read (void)
+{
+	return m_nValue;
+}
+
+void CMIDIPin::write (unsigned nValue)
+{
+	// Takes values in the MIDI controller range 0 to 127
+	// and OFF < 64 < ON.
+	// Simulates a PULLUP IO pin, so "true" is LOW (0)
+	if (nValue >= 64) {
+		// "on"
+		m_nValue = LOW;
+	} else {
+		// "off"
+		m_nValue = HIGH;
+	}
+	return;
+}
+

src/midipin.h

@@ -0,0 +1,54 @@
+//
+// midipin.h
+//
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+#ifndef _midipin_h
+#define _midipin_h
+
+#include <circle/gpiopin.h>
+#include <circle/types.h>
+
+// MIDI CC numbers go 0 to 127.
+// Normal GPIO pins are below 100.
+// So use a "pin number" of 128 + MIDI CC message for a "MIDI Pin"
+#define MIDI_PINS 128
+#define ccToMidiPin(c) ((c)+MIDI_PINS)
+#define MidiPinToCC(p) ((p)-MIDI_PINS)
+#define isMidiPin(p)   (((p)>=MIDI_PINS)?1:0)
+
+class CMIDIPin : public CGPIOPin
+{
+public:
+	CMIDIPin (unsigned nPinNumber);  // pinNumber = ccToMidiPin (MIDI CC number)
+	~CMIDIPin (void);
+
+	// Will return MP_HIGH or MP_LOW.
+	// Should be treated as a PULLED UP IO pin
+	// i.e. treated as "active low" (LOW) when pressed.
+	unsigned read (void);
+	
+	// MIDI CC values >=64 will set the MIDI pin to LOW ("on")
+	// MIDI CC values <= 63 will set the MIDI pin to HIGH ("off")
+	void write (unsigned nValue);
+
+private:
+	unsigned m_nPinNumber;
+	unsigned m_nValue;
+};
+
+#endif

src/minidexed.ini

@@ -57,6 +57,17 @@ ButtonPinShortcut=11
 DoubleClickTimeout=400
 LongPressTimeout=400
 
+# MIDI Button Navigation
+#  Specify MIDI CC to act as a button
+#  NB: Off < 64 < ON
+# CC channel: 0=OMNI; 1-16 MIDI Ch; >16 OFF
+MIDIButtonCh=255
+MIDIButtonPrev=85
+MIDIButtonNext=86
+MIDIButtonHome=87
+MIDIButtonSelect=89
+MIDIButtonBack=90
+
 # KY-040 Rotary Encoder
 EncoderEnabled=1
 EncoderPinClock=10

src/uibuttons.cpp

@@ -4,9 +4,6 @@
 // MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
 // Copyright (C) 2022  The MiniDexed Team
 //
-// Original author of this class:
-//	R. Stange <rsta2@o2online.de>
-//
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
@@ -72,7 +69,12 @@ boolean CUIButton::Initialize (unsigned pinNumber, unsigned doubleClickTimeout,
 
 	if (m_pinNumber != 0)
 	{
-		m_pin = new CGPIOPin (m_pinNumber, GPIOModeInputPullUp);
+		if (isMidiPin(m_pinNumber))
+		{
+			m_pin = new CMIDIPin (m_pinNumber);
+		} else {
+			m_pin = new CGPIOPin (m_pinNumber, GPIOModeInputPullUp);
+		}
 	}
 	return TRUE;
 }
@@ -233,7 +235,8 @@ CUIButtons::CUIButtons (
 			unsigned backPin, const char *backAction,
 			unsigned selectPin, const char *selectAction,
 			unsigned homePin, const char *homeAction,
-			unsigned doubleClickTimeout, unsigned longPressTimeout
+			unsigned doubleClickTimeout, unsigned longPressTimeout,
+			unsigned prevMidi, unsigned nextMidi, unsigned backMidi, unsigned selectMidi, unsigned homeMidi
 )
 :	m_doubleClickTimeout(doubleClickTimeout),
 	m_longPressTimeout(longPressTimeout),
@@ -247,6 +250,11 @@ CUIButtons::CUIButtons (
 	m_selectAction(CUIButton::triggerTypeFromString(selectAction)),
 	m_homePin(homePin),
 	m_homeAction(CUIButton::triggerTypeFromString(homeAction)),
+	m_prevMidi(prevMidi),
+	m_nextMidi(nextMidi),
+	m_backMidi(backMidi),
+	m_selectMidi(selectMidi),
+	m_homeMidi(homeMidi),
 	m_eventHandler (0),
 	m_lastTick (0)
 {
@@ -274,15 +282,27 @@ boolean CUIButtons::Initialize (void)
 		longPressTimeout = doubleClickTimeout;
 	}
 
-	// Each button can be assigned up to 3 actions: click, doubleclick and
-	// longpress. We may not initialise all of the buttons
+	// Each normal button can be assigned up to 3 actions: click, doubleclick and
+	// longpress. We may not initialise all of the buttons.
+	// MIDI buttons only support a single click.
 	unsigned pins[MAX_BUTTONS] = {
-		m_prevPin, m_nextPin, m_backPin, m_selectPin, m_homePin
+		m_prevPin, m_nextPin, m_backPin, m_selectPin, m_homePin,
+		m_prevMidi, m_nextMidi, m_backMidi, m_selectMidi, m_homeMidi
 	};
 	CUIButton::BtnTrigger triggers[MAX_BUTTONS] = {
-		m_prevAction, m_nextAction, m_backAction, m_selectAction, m_homeAction
+		// Normal buttons
+		m_prevAction, m_nextAction, m_backAction, m_selectAction, m_homeAction,
+		// MIDI Buttons only support a single click (at present)
+		CUIButton::BtnTriggerClick, CUIButton::BtnTriggerClick, CUIButton::BtnTriggerClick, CUIButton::BtnTriggerClick, CUIButton::BtnTriggerClick
 	};
 	CUIButton::BtnEvent events[MAX_BUTTONS] = {
+		// Normal buttons
+		CUIButton::BtnEventPrev,
+		CUIButton::BtnEventNext,
+		CUIButton::BtnEventBack,
+		CUIButton::BtnEventSelect,
+		CUIButton::BtnEventHome,
+		// MIDI buttons
 		CUIButton::BtnEventPrev,
 		CUIButton::BtnEventNext,
 		CUIButton::BtnEventBack,
@@ -290,7 +310,8 @@ boolean CUIButtons::Initialize (void)
 		CUIButton::BtnEventHome
 	};
 
-	for (unsigned i=0; i<MAX_BUTTONS; i++) {
+	// Setup normal GPIO buttons first
+	for (unsigned i=0; i<MAX_GPIO_BUTTONS; i++) {
 		// if this pin is 0 it means it's disabled - so continue
 		if (pins[i] == 0) {
 			continue;
@@ -311,6 +332,18 @@ boolean CUIButtons::Initialize (void)
 			}
 		}
 	}
+	
+	// Now setup the MIDI buttons.
+	// Note: the configuration is simpler as the only trigger supported is a single, short press
+	for (unsigned i=MAX_GPIO_BUTTONS; i<MAX_BUTTONS; i++) {
+		// if this pin is 0 it means it's disabled - so continue
+		if (pins[i] == 0) {
+			continue;
+		}
+
+		// doubleClickTimeout and longPressTimeout are ignored for MIDI buttons at present
+		m_buttons[i].Initialize(pins[i], doubleClickTimeout, longPressTimeout);
+	}	
 
 	// All of the buttons are now initialised, they just need to have their
 	// events assigned to them

src/uibuttons.h

@@ -4,9 +4,6 @@
 // MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
 // Copyright (C) 2022  The MiniDexed Team
 //
-// Original author of this class:
-//	R. Stange <rsta2@o2online.de>
-//
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
@@ -25,11 +22,14 @@
 
 #include <circle/gpiopin.h>
 #include <circle/types.h>
+#include "midipin.h"
 #include "config.h"
 
 #define BUTTONS_UPDATE_NUM_TICKS 100
 #define DEBOUNCE_TIME 100
-#define MAX_BUTTONS 5
+#define MAX_GPIO_BUTTONS 5
+#define MAX_MIDI_BUTTONS 5
+#define MAX_BUTTONS (MAX_GPIO_BUTTONS+MAX_MIDI_BUTTONS)
 
 class CUIButtons;
 
@@ -110,7 +110,8 @@ public:
 			unsigned backPin, const char *backAction,
 			unsigned selectPin, const char *selectAction,
 			unsigned homePin, const char *homeAction,
-			unsigned doubleClickTimeout, unsigned longPressTimeout
+			unsigned doubleClickTimeout, unsigned longPressTimeout,
+			unsigned prevMidi, unsigned nextMidi, unsigned backMidi, unsigned selectMidi, unsigned homeMidi
 	);
 	~CUIButtons (void);
 	
@@ -123,7 +124,7 @@ public:
 	void ResetButton (unsigned pinNumber);
 	
 private:
-	// Array of 5 buttons
+	// Array of normal GPIO buttons and "MIDI buttons"
 	CUIButton m_buttons[MAX_BUTTONS];
 	
 	// Timeout for double click in tenths of a millisecond
@@ -142,6 +143,13 @@ private:
 	CUIButton::BtnTrigger m_selectAction;
 	unsigned m_homePin;
 	CUIButton::BtnTrigger m_homeAction;
+	
+	// MIDI button configuration
+	unsigned m_prevMidi;
+	unsigned m_nextMidi;
+	unsigned m_backMidi;
+	unsigned m_selectMidi;
+	unsigned m_homeMidi;
 
 	BtnEventHandler *m_eventHandler;
 	void *m_eventParam;

src/userinterface.cpp

@@ -27,6 +27,8 @@
 
 LOGMODULE ("ui");
 
+unsigned CUserInterface::nMIDIButtonCh = 255;
+
 CUserInterface::CUserInterface (CMiniDexed *pMiniDexed, CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, CConfig *pConfig)
 :	m_pMiniDexed (pMiniDexed),
 	m_pGPIOManager (pGPIOManager),
@@ -114,7 +116,13 @@ bool CUserInterface::Initialize (void)
 									m_pConfig->GetButtonPinHome (),
 									m_pConfig->GetButtonActionHome (),
 									m_pConfig->GetDoubleClickTimeout (),
-									m_pConfig->GetLongPressTimeout () );
+									m_pConfig->GetLongPressTimeout (),
+									m_pConfig->GetMIDIButtonNext (),
+									m_pConfig->GetMIDIButtonPrev (),
+									m_pConfig->GetMIDIButtonBack (),
+									m_pConfig->GetMIDIButtonSelect (),
+									m_pConfig->GetMIDIButtonHome ()
+								  );
 	assert (m_pUIButtons);
 
 	if (!m_pUIButtons->Initialize ())
@@ -123,6 +131,7 @@ bool CUserInterface::Initialize (void)
 	}
 
 	m_pUIButtons->RegisterEventHandler (UIButtonsEventStub, this);
+	nMIDIButtonCh = m_pConfig->GetMIDIButtonCh ();
 
 	LOGDBG ("Button User Interface initialized");
 
@@ -322,3 +331,12 @@ void CUserInterface::UIButtonsEventStub (CUIButton::BtnEvent Event, void *pParam
 
 	pThis->UIButtonsEventHandler (Event);
 }
+
+void CUserInterface::UIMIDICCHandler (unsigned nMidiCh, unsigned nMidiCC, unsigned nMidiData)
+{
+	if ((nMIDIButtonCh != nMidiCh) && (nMIDIButtonCh != 0))
+	{
+		// Message not on the MIDI Button channel and MIDI buttons not in OMNI mode
+		return;
+	}
+}

src/userinterface.h

@@ -52,6 +52,9 @@ public:
 	void DisplayWrite (const char *pMenu, const char *pParam, const char *pValue,
 			   bool bArrowDown, bool bArrowUp);
 
+	// To be called from the MIDI device on reception of a MIDI CC message
+	static void UIMIDICCHandler (unsigned nMidiCh, unsigned nMidiCC, unsigned nMidiData);
+
 private:
 	void LCDWrite (const char *pString);		// Print to optional HD44780 display
 
@@ -73,6 +76,8 @@ private:
 	
 	CUIButtons *m_pUIButtons;
 
+	static unsigned nMIDIButtonCh;
+
 	CKY040 *m_pRotaryEncoder;
 	bool m_bSwitchPressed;