First "it seems to work for me" version for initial testing of MIDI buttons.

src/config.cpp

@@ -104,7 +104,7 @@ 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_nMIDIButtonCh = m_Properties.GetNumber ("MIDIButtonCh", 0);
 	m_nMIDIButtonPrev = m_Properties.GetNumber ("MIDIButtonPrev", 0);
 	m_nMIDIButtonNext = m_Properties.GetNumber ("MIDIButtonNext", 0);
 	m_nMIDIButtonBack = m_Properties.GetNumber ("MIDIButtonBack", 0);

src/mididevice.h

@@ -28,6 +28,7 @@
 #include <unordered_map>
 #include <circle/types.h>
 #include <circle/spinlock.h>
+#include "userinterface.h"
 
 class CMiniDexed;
 
@@ -43,7 +44,7 @@ public:
 	};
 
 public:
-	CMIDIDevice (CMiniDexed *pSynthesizer, CConfig *pConfig);
+	CMIDIDevice (CMiniDexed *pSynthesizer, CConfig *pConfig, CUserInterface *pUI);
 	virtual ~CMIDIDevice (void);
 
 	void SetChannel (u8 ucChannel, unsigned nTG);
@@ -59,6 +60,7 @@ protected:
 private:
 	CMiniDexed *m_pSynthesizer;
 	CConfig *m_pConfig;
+	CUserInterface *m_pUI;
 
 	u8 m_ChannelMap[CConfig::ToneGenerators];
 

src/midipin.cpp

@@ -33,12 +33,12 @@ CMIDIPin::~CMIDIPin (void)
 {
 }
 		
-unsigned CMIDIPin::read (void)
+unsigned CMIDIPin::Read (void)
 {
 	return m_nValue;
 }
 
-void CMIDIPin::write (unsigned nValue)
+void CMIDIPin::Write (unsigned nValue)
 {
 	// Takes values in the MIDI controller range 0 to 127
 	// and OFF < 64 < ON.

src/midipin.h

@@ -31,7 +31,7 @@
 #define MidiPinToCC(p) ((p)-MIDI_PINS)
 #define isMidiPin(p)   (((p)>=MIDI_PINS)?1:0)
 
-class CMIDIPin : public CGPIOPin
+class CMIDIPin
 {
 public:
 	CMIDIPin (unsigned nPinNumber);  // pinNumber = ccToMidiPin (MIDI CC number)
@@ -40,11 +40,11 @@ public:
 	// 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);
+	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);
+	void Write (unsigned nValue);
 
 private:
 	unsigned m_nPinNumber;

src/minidexed.cpp

@@ -39,8 +39,8 @@ CMiniDexed::CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
 	m_pConfig (pConfig),
 	m_UI (this, pGPIOManager, pI2CMaster, pConfig),
 	m_PerformanceConfig (pFileSystem),
-	m_PCKeyboard (this, pConfig),
-	m_SerialMIDI (this, pInterrupt, pConfig),
+	m_PCKeyboard (this, pConfig, &m_UI),
+	m_SerialMIDI (this, pInterrupt, pConfig, &m_UI),
 	m_bUseSerial (false),
 	m_pSoundDevice (0),
 	m_bChannelsSwapped (pConfig->GetChannelsSwapped ()),
@@ -98,7 +98,7 @@ CMiniDexed::CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
 
 	for (unsigned i = 0; i < CConfig::MaxUSBMIDIDevices; i++)
 	{
-		m_pMIDIKeyboard[i] = new CMIDIKeyboard (this, pConfig, i);
+		m_pMIDIKeyboard[i] = new CMIDIKeyboard (this, pConfig, &m_UI, i);
 		assert (m_pMIDIKeyboard[i]);
 	}
 

src/uibuttons.cpp

@@ -28,6 +28,7 @@ LOGMODULE ("uibuttons");
 CUIButton::CUIButton (void)
 :	m_pinNumber (0),
 	m_pin (0),
+	m_midipin (0),
 	m_lastValue (1),
 	m_timer (0),
 	m_debounceTimer (0),
@@ -46,6 +47,10 @@ CUIButton::~CUIButton (void)
 	{
 		delete m_pin;
 	}
+	if (m_midipin)
+	{
+		delete m_midipin;
+	}
 }
 
 void CUIButton::reset (void)
@@ -71,8 +76,10 @@ boolean CUIButton::Initialize (unsigned pinNumber, unsigned doubleClickTimeout,
 	{
 		if (isMidiPin(m_pinNumber))
 		{
-			m_pin = new CMIDIPin (m_pinNumber);
+			LOGDBG("MIDI Button on pin: %d (%x)", m_pinNumber, m_pinNumber);
+			m_midipin = new CMIDIPin (m_pinNumber);
 		} else {
+			LOGDBG("GPIO Button on pin: %d (%x)", m_pinNumber, m_pinNumber);
 			m_pin = new CGPIOPin (m_pinNumber, GPIOModeInputPullUp);
 		}
 	}
@@ -101,13 +108,25 @@ unsigned CUIButton::getPinNumber(void)
 	
 CUIButton::BtnTrigger CUIButton::ReadTrigger (void)
 {
-	if (!m_pin)
+	unsigned value;
+	if (isMidiPin(m_pinNumber))
 	{
-		// Always return "not pressed" if not configured
-		return BtnTriggerNone;
+		if (!m_midipin)
+		{
+			// Always return "not pressed" if not configured
+			return BtnTriggerNone;
+		}
+		value = m_midipin->Read();
+	}
+	else
+	{
+		if (!m_pin)
+		{
+			// Always return "not pressed" if not configured
+			return BtnTriggerNone;
+		}
+		value = m_pin->Read();
 	}
-
-	unsigned value = m_pin->Read();
 
 	if (m_timer < m_longPressTimeout) {
 		m_timer++;
@@ -192,14 +211,10 @@ CUIButton::BtnTrigger CUIButton::ReadTrigger (void)
 
 void CUIButton::Write (unsigned nValue) {
 	// This only makes sense for MIDI buttons.
-	unsigned pin = getPinNumber();
-	if (isMidiPin(pin))
+	if (m_midipin && isMidiPin(m_pinNumber))
 	{
-		if (m_pin)
-		{
-			// Update the "MIDI Pin"
-			m_pin->Write(nValue);
-		}
+		// Update the "MIDI Pin"
+		m_midipin->Write(nValue);
 	}
 }
 
@@ -263,11 +278,11 @@ 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_prevMidi(ccToMidiPin(prevMidi)),
+	m_nextMidi(ccToMidiPin(nextMidi)),
+	m_backMidi(ccToMidiPin(backMidi)),
+	m_selectMidi(ccToMidiPin(selectMidi)),
+	m_homeMidi(ccToMidiPin(homeMidi)),
 	m_eventHandler (0),
 	m_lastTick (0)
 {
@@ -354,9 +369,16 @@ boolean CUIButtons::Initialize (void)
 			continue;
 		}
 
-		// doubleClickTimeout and longPressTimeout are ignored for MIDI buttons at present
-		m_buttons[i].Initialize(pins[i], doubleClickTimeout, longPressTimeout);
-	}	
+		// Carry on in the list from where GPIO buttons left off
+		for (unsigned j=0; j<MAX_BUTTONS; j++) {
+			if (m_buttons[j].getPinNumber() == 0) {
+				// This is un-initialised so can be assigned
+				// doubleClickTimeout and longPressTimeout are ignored for MIDI buttons at present
+				m_buttons[j].Initialize(pins[i], doubleClickTimeout, longPressTimeout);
+				break;
+			}
+		}
+	}
 
 	// All of the buttons are now initialised, they just need to have their
 	// events assigned to them

src/uibuttons.h

@@ -78,6 +78,8 @@ private:
 	unsigned m_pinNumber;
 	// GPIO pin
 	CGPIOPin *m_pin;
+	// MIDI pin
+	CMIDIPin *m_midipin;
 	// The value of the pin at the end of the last loop
 	unsigned m_lastValue;
 	// Set to 0 on press, increment each read, use to trigger events

src/userinterface.cpp

@@ -129,7 +129,7 @@ bool CUserInterface::Initialize (void)
 	}
 
 	m_pUIButtons->RegisterEventHandler (UIButtonsEventStub, this);
-	m_nMIDIButtonCh = m_pConfig->GetMIDIButtonCh ();
+	UISetMIDICCChannel (m_pConfig->GetMIDIButtonCh ());
 
 	LOGDBG ("Button User Interface initialized");
 
@@ -332,7 +332,12 @@ void CUserInterface::UIButtonsEventStub (CUIButton::BtnEvent Event, void *pParam
 
 void CUserInterface::UIMIDICCHandler (unsigned nMidiCh, unsigned nMidiCC, unsigned nMidiData)
 {
-	if ((m_nMIDIButtonCh != nMidiCh) && (m_nMIDIButtonCh != 0))
+	if (m_nMIDIButtonCh == CMIDIDevice::Disabled)
+	{
+		// MIDI buttons are not enabled
+		return;
+	}
+	if ((m_nMIDIButtonCh != nMidiCh) && (m_nMIDIButtonCh != CMIDIDevice::OmniMode))
 	{
 		// Message not on the MIDI Button channel and MIDI buttons not in OMNI mode
 		return;
@@ -343,3 +348,20 @@ void CUserInterface::UIMIDICCHandler (unsigned nMidiCh, unsigned nMidiCC, unsign
 		m_pUIButtons->BtnMIDICCHandler (nMidiCC, nMidiData);
 	}
 }
+
+void CUserInterface::UISetMIDICCChannel (unsigned uCh)
+{
+	// Mirrors the logic in Performance Config for handling MIDI channel configuration
+	if (uCh == 0)
+	{
+		m_nMIDIButtonCh = CMIDIDevice::Disabled;
+	}
+	else if (uCh < CMIDIDevice::Channels)
+	{
+		m_nMIDIButtonCh = uCh - 1;
+	}
+	else
+	{
+		m_nMIDIButtonCh = CMIDIDevice::OmniMode;
+	}
+}

src/userinterface.h

@@ -62,6 +62,7 @@ private:
 	static void EncoderEventStub (CKY040::TEvent Event, void *pParam);
 	void UIButtonsEventHandler (CUIButton::BtnEvent Event);
 	static void UIButtonsEventStub (CUIButton::BtnEvent Event, void *pParam);
+	void UISetMIDICCChannel (unsigned uCh);
 
 private:
 	CMiniDexed *m_pMiniDexed;