Initial support for I2C HD44780 displays (#225)

Initial support for I2C HD44780 displays, closes #169
Thanks @diyelectromusic

.github/workflows/build.yml

@@ -20,11 +20,11 @@ jobs:
       run: |
            set -ex
            git submodule update --init --recursive
-    - name: Use Circle develop branch for WM8960 support until it is merged upstream
+    - name: Use Circle develop branch for WM8960 and i2c display support until it is merged upstream
       run: |
            set -ex
            cd circle-stdlib/libs/circle
-           git checkout ae22928 # develop
+           git checkout c9a4815 # develop
            cd -
     - name: Install toolchains
       run: |

src/config.cpp

@@ -79,6 +79,7 @@ void CConfig::Load (void)
 	m_nLCDPinData5 = m_Properties.GetNumber ("LCDPinData5", 23);
 	m_nLCDPinData6 = m_Properties.GetNumber ("LCDPinData6", 24);
 	m_nLCDPinData7 = m_Properties.GetNumber ("LCDPinData7", 25);
+	m_nLCDI2CAddress = m_Properties.GetNumber ("LCDI2CAddress", 0);
 
 	m_bEncoderEnabled = m_Properties.GetNumber ("EncoderEnabled", 0) != 0;
 	m_nEncoderPinClock = m_Properties.GetNumber ("EncoderPinClock", 10);
@@ -174,6 +175,11 @@ unsigned CConfig::GetLCDPinData7 (void) const
 	return m_nLCDPinData7;
 }
 
+unsigned CConfig::GetLCDI2CAddress (void) const
+{
+	return m_nLCDI2CAddress;
+}
+
 bool CConfig::GetEncoderEnabled (void) const
 {
 	return m_bEncoderEnabled;

src/config.h

@@ -86,6 +86,7 @@ public:
 	unsigned GetLCDPinData5 (void) const;
 	unsigned GetLCDPinData6 (void) const;
 	unsigned GetLCDPinData7 (void) const;
+	unsigned GetLCDI2CAddress (void) const;
 
 	// KY-040 Rotary Encoder
 	// GPIO pin numbers are chip numbers, not header positions
@@ -120,6 +121,7 @@ private:
 	unsigned m_nLCDPinData5;
 	unsigned m_nLCDPinData6;
 	unsigned m_nLCDPinData7;
+	unsigned m_nLCDI2CAddress;
 
 	bool m_bEncoderEnabled;
 	unsigned m_nEncoderPinClock;

src/minidexed.cpp

@@ -37,7 +37,7 @@ CMiniDexed::CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
 	CMultiCoreSupport (CMemorySystem::Get ()),
 #endif
 	m_pConfig (pConfig),
-	m_UI (this, pGPIOManager, pConfig),
+	m_UI (this, pGPIOManager, pI2CMaster, pConfig),
 	m_PerformanceConfig (pFileSystem),
 	m_PCKeyboard (this, pConfig),
 	m_SerialMIDI (this, pInterrupt, pConfig),

src/minidexed.ini

@@ -25,6 +25,7 @@ LCDPinData4=22
 LCDPinData5=23
 LCDPinData6=24
 LCDPinData7=25
+LCDI2CAddress=0x00
 
 # KY-040 Rotary Encoder
 EncoderEnabled=1

src/userinterface.cpp

@@ -27,9 +27,10 @@
 
 LOGMODULE ("ui");
 
-CUserInterface::CUserInterface (CMiniDexed *pMiniDexed, CGPIOManager *pGPIOManager, CConfig *pConfig)
+CUserInterface::CUserInterface (CMiniDexed *pMiniDexed, CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, CConfig *pConfig)
 :	m_pMiniDexed (pMiniDexed),
 	m_pGPIOManager (pGPIOManager),
+	m_pI2CMaster (pI2CMaster),
 	m_pConfig (pConfig),
 	m_pLCD (0),
 	m_pLCDBuffered (0),
@@ -51,6 +52,9 @@ bool CUserInterface::Initialize (void)
 	assert (m_pConfig);
 
 	if (m_pConfig->GetLCDEnabled ())
+	{
+		unsigned i2caddr = m_pConfig->GetLCDI2CAddress ();
+		if (i2caddr == 0)
 		{
 			m_pLCD = new CHD44780Device (CConfig::LCDColumns, CConfig::LCDRows,
 							 m_pConfig->GetLCDPinData4 (),
@@ -60,6 +64,12 @@ bool CUserInterface::Initialize (void)
 							 m_pConfig->GetLCDPinEnable (),
 							 m_pConfig->GetLCDPinRegisterSelect (),
 							 m_pConfig->GetLCDPinReadWrite ());
+		}
+		else
+		{
+			m_pLCD = new CHD44780Device (m_pI2CMaster, i2caddr,
+							CConfig::LCDColumns, CConfig::LCDRows);
+		}
 		assert (m_pLCD);
 
 		if (!m_pLCD->Initialize ())

src/userinterface.h

@@ -26,13 +26,14 @@
 #include <display/hd44780device.h>
 #include <circle/gpiomanager.h>
 #include <circle/writebuffer.h>
+#include <circle/i2cmaster.h>
 
 class CMiniDexed;
 
 class CUserInterface
 {
 public:
-	CUserInterface (CMiniDexed *pMiniDexed, CGPIOManager *pGPIOManager, CConfig *pConfig);
+	CUserInterface (CMiniDexed *pMiniDexed, CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, CConfig *pConfig);
 	~CUserInterface (void);
 
 	bool Initialize (void);
@@ -58,6 +59,7 @@ private:
 private:
 	CMiniDexed *m_pMiniDexed;
 	CGPIOManager *m_pGPIOManager;
+	CI2CMaster *m_pI2CMaster;
 	CConfig *m_pConfig;
 
 	CHD44780Device *m_pLCD;