Added support for font chip on TFT display

11 files changed, 381 insertions, 22 deletions

diff --git a/src/Config/Pins.h b/src/Config/Pins.h
index 3ef1c5e7..e2500106 100644
--- a/src/Config/Pins.h
+++ b/src/Config/Pins.h
@@ -72,6 +72,10 @@
 # define SUPPORT_ILI9488_LCD	0
 #endif
 
+#ifndef USE_FONT_CHIP
+# define USE_FONT_CHIP		0
+#endif
+
 #define SUPPORT_DIRECT_LCD		(SUPPORT_12864_LCD || SUPPORT_ILI9488_LCD)
 #define SUPPORT_ROTARY_ENCODER	SUPPORT_12864_LCD
 #define SUPPORT_RESISTIVE_TOUCH	SUPPORT_ILI9488_LCD
diff --git a/src/Config/Pins_FMDC.h b/src/Config/Pins_FMDC.h
index 8e3baa69..40895d7a 100644
--- a/src/Config/Pins_FMDC.h
+++ b/src/Config/Pins_FMDC.h
@@ -52,6 +52,7 @@ constexpr uint32_t IAP_IMAGE_START = 0x20028000;
 #define SUPPORT_WORKPLACE_COORDINATES	1			// set nonzero to support G10 L2 and G53..59
 #define SUPPORT_12864_LCD		0					// set nonzero to support 12864 LCD and rotary encoder
 #define SUPPORT_ILI9488_LCD		1
+#define USE_FONT_CHIP			1
 #define SUPPORT_ACCELEROMETERS	1
 #define SUPPORT_OBJECT_MODEL	1
 #define SUPPORT_FTP				0
@@ -242,9 +243,11 @@ constexpr Pin LcdResetPin = PortCPin(6);
 #if defined(FMDC_V03)
 constexpr Pin LcdFlashCsPin = PortAPin(20);
 constexpr Pin LcdBacklightPin = PortBPin(16);
+constexpr Pin LcdFontCsPin = PortBPin(20);
 #elif defined(FMDC_V02)
 constexpr Pin LcdFlashCsPin = PortBPin(10);
 constexpr Pin LcdBacklightPin = PortBPin(12);
+constexpr Pin LcdFontCsPin = PortBPin(15);
 #endif
 
 constexpr Pin LcdFlashWpPin = PortAPin(2);
@@ -403,7 +406,7 @@ constexpr PinDescription PinTable[] =
 #elif defined(FMDC_V02)
 	{ TcOutput::none,	TccOutput::none,	AdcInput::none,		SercomIo::none,		SercomIo::none,		Nx,	PinCapability::none,	nullptr				},	// PB18 SDHC DAT0
 	{ TcOutput::none,	TccOutput::none,	AdcInput::none,		SercomIo::none,		SercomIo::none,		Nx,	PinCapability::none,	nullptr				},	// PB19 SDHC DAT1
-	{ TcOutput::none,	TccOutput::none,	AdcInput::none,		SercomIo::none,		SercomIo::none,		Nx,	PinCapability::none,	nullptr				},	// PB20 SDHC DAT2
+	{ TcOutput::none,	TccOutput::none,	AdcInput::none,		SercomIo::none,		SercomIo::none,		Nx,	PinCapability::none,	"ate.lcd.fontcs"	},	// PB20 SDHC DAT2
 	{ TcOutput::none,	TccOutput::none,	AdcInput::none,		SercomIo::none,		SercomIo::none,		Nx,	PinCapability::none,	nullptr				},	// PB21 SDHC DAT3
 #endif
 	{ TcOutput::none,	TccOutput::none,	AdcInput::none,		SercomIo::none,		SercomIo::none,		Nx,	PinCapability::none,	nullptr				},	// PB22 crystal XIN1
diff --git a/src/Display/Display.cpp b/src/Display/Display.cpp
index a114921a..1cf2c256 100644
--- a/src/Display/Display.cpp
+++ b/src/Display/Display.cpp
@@ -34,12 +34,17 @@ constexpr size_t LargeFontNumber = 1;
 #endif
 
 #if SUPPORT_ILI9488_LCD
+# if USE_FONT_CHIP
+constexpr size_t SmallFontNumber = 0;
+constexpr size_t LargeFontNumber = 1;
+# else
 // The FMDC prototypes don't have enough flash memory for more than one font
 //extern const LcdFont font19x21;
 extern const LcdFont font28x32;
 const LcdFont * const tftFonts[] = { /*&font19x21 ,*/ &font28x32 };
 constexpr size_t SmallFontNumber = 0;
 constexpr size_t LargeFontNumber = 0;
+# endif
 #endif
 
 constexpr uint32_t NormalRefreshMillis = 250;
@@ -254,7 +259,14 @@ GCodeResult Display::Configure(GCodeBuffer& gb, const StringRef& reply) THROWS(G
 			SetPinFunction(LcdSpiMosiPin, LcdSpiPinFunction);
 			SetPinFunction(LcdSpiMisoPin, LcdSpiPinFunction);
 			SetPinFunction(LcdSpiSclkPin, LcdSpiPinFunction);
-			InitDisplay(gb, new LcdILI9488(tftFonts, ARRAY_SIZE(tftFonts), LcdSercomNumber), LcdSpiCsPin, NoPin, false);
+			pinMode(LcdFlashCsPin, OUTPUT_HIGH);							// in case the flash chip is fitted, deselect it
+			InitDisplay(gb,
+# if USE_FONT_CHIP
+							new LcdILI9488(LcdFontCsPin, LcdSercomNumber),
+# else
+							new LcdILI9488(tftFonts, ARRAY_SIZE(tftFonts), LcdSercomNumber),
+# endif
+								LcdSpiCsPin, NoPin, false);
 			touchController = new ResistiveTouch(RtpSpiCsPin, RtpPenPin);
 			touchController->Init(lcd->GetNumCols(), lcd->GetNumRows(), DisplayOrientation::ReverseY);
 			break;
diff --git a/src/Display/Lcd/Fonts/ER3301_1.cpp b/src/Display/Lcd/Fonts/ER3301_1.cpp
new file mode 100644
index 00000000..d3296294
--- /dev/null
+++ b/src/Display/Lcd/Fonts/ER3301_1.cpp
@@ -0,0 +1,199 @@
+/*
+ * ER3301_1.cpp
+ *
+ *  Created on: 27 May 2022
+ *      Author: David
+ *
+ *  Support for ER3303-1 font chip included on some variants of the ER-TFTM035-6 display
+ */
+
+#include "ER3301_1.h"
+
+#if USE_FONT_CHIP
+
+#include <Hardware/Spi/SharedSpiDevice.h>
+
+// This font chip contains several fonts. We are only interested in the 12-dot and 16 dot high Unicode Latin/Greek Cyrillic and Arabic fonts.
+// We number those as fonts 0 and 1. Fonts 2 and 3 are the same ones expanded to double size.
+
+struct FontTableEntry
+{
+	uint16_t startCharacter;
+	uint16_t endCharacter;
+	uint32_t startAddress;
+};
+
+struct FontDescriptor
+{
+	const FontTableEntry *tableStart;
+	const FontTableEntry *tableEnd;
+	uint16_t height;
+	uint16_t spaceWidth;
+	unsigned int bytesPerCharacter;
+};
+
+static constexpr FontTableEntry Font12[] =
+{
+	{ 0x0020, 0x007F, 0x19AD22 },						// Latin
+	{ 0x00A0, 0x017F, 0x19AD22 + 96 * 26},				// Latin
+	{ 0x0384, 0x03CE, 0x19AD22 + 350 * 26 },			// Greek
+	{ 0x0400, 0x045F, 0x19AD22 + 425 * 26 },			// Cyrillic
+	{ 0x0490, 0x04A3, 0x19AD22 + (425 + 96) * 26 },		// Cyrillic
+	{ 0x04AE, 0x04B3, 0x19AD22 + (425 + 117) * 26 },	// Cyrillic
+	{ 0x04B8, 0x04BB, 0x19AD22 + (425 + 122) * 26 },	// Cyrillic
+	{ 0x04D8, 0x04D9, 0x19AD22 + (425 + 126) * 26 },	// Cyrillic
+	{ 0x04E8, 0x04E9, 0x19AD22 + (425 + 128) * 26 },	// Cyrillic
+	{ 0x0600, 0x06F9, 0x1AA0E6 }						// Arabic
+};
+
+static constexpr FontTableEntry Font16[] =
+{
+	{ 0x0020, 0x007F, 0x19E580 },						// Latin
+	{ 0x00A0, 0x017F, 0x19E580 + 96 * 34},				// Latin
+	{ 0x0384, 0x03CE, 0x19E580 + 350 * 34 },			// Greek
+	{ 0x0400, 0x045F, 0x19E580 + 425 * 34 },			// Cyrillic
+	{ 0x0490, 0x04A3, 0x19E580 + (425 + 96) * 34 },		// Cyrillic
+	{ 0x04AE, 0x04B3, 0x19E580 + (425 + 117) * 34 },	// Cyrillic
+	{ 0x04B8, 0x04BB, 0x19E580 + (425 + 122) * 34 },	// Cyrillic
+	{ 0x04D8, 0x04D9, 0x19E580 + (425 + 126) * 34 },	// Cyrillic
+	{ 0x04E8, 0x04E9, 0x19E580 + (425 + 128) * 34 },	// Cyrillic
+	{ 0x0600, 0x06F9, 0x1A2F36 }						// Arabic
+};
+
+static constexpr FontDescriptor Fonts[] =
+{
+	{ Font12, Font12 + ARRAY_SIZE(Font12), 12, 1, 26 },
+	{ Font16, Font16 + ARRAY_SIZE(Font16), 16, 1, 34 },
+};
+
+constexpr bool FontSizeOK(const FontDescriptor *descriptor, size_t numFonts) noexcept
+{
+	return descriptor->bytesPerCharacter <= ER3301_1::MaxBytesPerCharacter && (numFonts == 1 || FontSizeOK(descriptor + 1, numFonts - 1));
+}
+
+static_assert(FontSizeOK(Fonts, ARRAY_SIZE(Fonts)));
+
+// Search for a character in the font table, returning its address of found, 0 if not found
+static uint32_t LookupCharacter(uint16_t codePoint, const FontDescriptor& font) noexcept
+{
+	const FontTableEntry *table = font.tableStart;
+	do
+	{
+		if (codePoint <= table->endCharacter)
+		{
+			if (codePoint >= table->startCharacter)
+			{
+				return table->startAddress + ((codePoint - table->startCharacter) * font.bytesPerCharacter);
+			}
+			break;
+		}
+		++table;
+	} while (table != font.tableEnd);
+	return 0;
+}
+
+ER3301_1::ER3301_1(Pin csPin) noexcept
+	: spiClient(SharedSpiDevice::GetMainSharedSpiDevice(), SpiFrequency, SpiMode::mode0, csPin, false), currentAddress(0)
+{
+}
+
+// Return the count of available fonts
+unsigned int ER3301_1::GetNumFonts() const noexcept
+{
+	return 2 * ARRAY_SIZE(Fonts);
+}
+
+// Return the height of the specified font
+uint16_t ER3301_1::GetFontHeight(unsigned int fontNumber) const noexcept
+{
+	const uint16_t nativeFontHeight = Fonts[fontNumber % ARRAY_SIZE(Fonts)].height;
+	return (fontNumber >= ARRAY_SIZE(Fonts)) ? 2 * nativeFontHeight : nativeFontHeight;
+}
+
+// Get the inter-character spacing in the specified font
+uint16_t ER3301_1::GetSpacing(unsigned int fontNumber) const noexcept
+{
+	const uint16_t nativeSpacing = Fonts[fontNumber % ARRAY_SIZE(Fonts)].spaceWidth;
+	return (fontNumber >= ARRAY_SIZE(Fonts)) ? 2 * nativeSpacing : nativeSpacing;
+}
+
+// Fetch the data for the next column and advance the column counter
+uint32_t ER3301_1::GetColumnData(uint16_t column) noexcept
+{
+	uint32_t ret = 0;
+	if (doubleSize)
+	{
+		for (unsigned int row = 0; row < nativeHeight; ++row)
+		{
+			const uint16_t data = __builtin_bswap16(charBuffer.data[row]);
+			if ((data << ((column >> 1) + columnOffset)) & 0x8000)		// if pixel is set
+			{
+				ret |= 3u << (row << 1);
+			}
+		}
+	}
+	else
+	{
+		for (unsigned int row = 0; row < nativeHeight; ++row)
+		{
+			const uint16_t data = __builtin_bswap16(charBuffer.data[row]);
+			if ((data << (column + columnOffset)) & 0x8000)				// if pixel is set
+			{
+				ret |= 1u << row;
+			}
+		}
+	}
+	return ret;
+}
+
+// Fetch the specified character into the buffer, set nextColumn to zero and return its width
+uint16_t ER3301_1::GetCharacter(unsigned int fontNumber, uint16_t codePoint) noexcept
+{
+	uint32_t addr = LookupCharacter(codePoint, Fonts[fontNumber % ARRAY_SIZE(Fonts)]);
+	if (addr == 0)
+	{
+		addr = LookupCharacter(0x007F, Fonts[fontNumber % ARRAY_SIZE(Fonts)]);
+		if (addr == 0)
+		{
+			return 0;
+		}
+	}
+	if (addr != currentAddress)
+	{
+		// Fetch the character from the font chip
+		spiClient.Select();
+		charBuffer.cmd = 0x03;
+		charBuffer.addr[0] = (uint8_t)(addr >> 16);
+		charBuffer.addr[1] = (uint8_t)(addr >> 8);
+		charBuffer.addr[2] = (uint8_t)addr;
+		spiClient.TransceivePacket((const uint8_t *)&charBuffer, (uint8_t *)&charBuffer, 4 + Fonts[fontNumber % ARRAY_SIZE(Fonts)].bytesPerCharacter);
+		spiClient.Deselect();
+
+		currentAddress = addr;
+		nativeHeight = Fonts[fontNumber % ARRAY_SIZE(Fonts)].height;		// this is the native height
+		nativeWidth = __builtin_bswap16(charBuffer.width);
+
+		// Check whether there is a leading blank column that we need to remove
+		uint16_t pixels = 0;
+		for (unsigned int row = 0; row < nativeHeight; ++row)
+		{
+			pixels |= charBuffer.data[row];
+		}
+		if ((pixels & 0x0080) != 0 && nativeWidth != 0)			// use 0x0080 instead of 0x8000 because we didn't swap the bytes
+		{
+			columnOffset = 0;
+		}
+		else
+		{
+			// Remove the leading space column
+			--nativeWidth;
+			columnOffset = 1;
+		}
+	}
+	doubleSize = (fontNumber >= ARRAY_SIZE(Fonts));
+	return (doubleSize) ? 2 * nativeWidth : nativeWidth;
+}
+
+#endif
+
+// End
diff --git a/src/Display/Lcd/Fonts/ER3301_1.h b/src/Display/Lcd/Fonts/ER3301_1.h
new file mode 100644
index 00000000..ee999aa9
--- /dev/null
+++ b/src/Display/Lcd/Fonts/ER3301_1.h
@@ -0,0 +1,62 @@
+/*
+ * ER3301_1.h
+ *
+ *  Created on: 27 May 2022
+ *      Author: David
+ */
+
+#ifndef SRC_DISPLAY_LCD_FONTS_ER3301_1_H_
+#define SRC_DISPLAY_LCD_FONTS_ER3301_1_H_
+
+#include <RepRapFirmware.h>
+
+#if USE_FONT_CHIP
+
+#include <Hardware/Spi/SharedSpiClient.h>
+
+class ER3301_1
+{
+public:
+	ER3301_1(Pin csPin) noexcept;
+
+	// Return the count of available fonts
+	unsigned int GetNumFonts() const noexcept;
+
+	// Return the height of the specified font
+	uint16_t GetFontHeight(unsigned int fontNumber) const noexcept;
+
+	// Get the inter-character spacing in the specified font
+	uint16_t GetSpacing(unsigned int fontNumber) const noexcept;
+
+	// Fetch the specified character into the buffer and return its width
+	uint16_t GetCharacter(unsigned int fontNumber, uint16_t codePoint) noexcept;
+
+	// Fetch the data for the next column and advance the column counter
+	uint32_t GetColumnData(uint16_t column) noexcept;
+
+	static constexpr size_t MaxBytesPerCharacter = 34;
+
+private:
+	static constexpr uint32_t SpiFrequency = 4000000;			// the SPI frequency we use (max supported is 20MHz in Read mode, 30MHz in FastRead mode)
+
+	SharedSpiClient spiClient;
+	uint32_t currentAddress;									// the address for which we have a character in the buffer
+	uint16_t nativeHeight;										// the native height of the character in the buffer
+	uint16_t nativeWidth;										// the width of the character in the buffer, after removing a leading space if we need to
+	uint16_t columnOffset;										// the number of words of leading spaces we need to skip (we need to manage spaces ourselves to do auto kerning)
+	bool doubleSize;											// true if the current font scales the size by two
+
+	struct CharData
+	{
+		uint8_t cmd;											// space for the Read command
+		uint8_t addr[3];										// the 3-byte address we want, MSB first
+		uint16_t width;											// the width of the character
+		uint16_t data[MaxBytesPerCharacter/2 - 1];				// the character data, one word per row
+	};
+
+	CharData charBuffer;										// buffer to hold the SPI command and the fetched font data
+};
+
+#endif
+
+#endif /* SRC_DISPLAY_LCD_FONTS_ER3301_1_H_ */
diff --git a/src/Display/Lcd/ILI9488/ILI9488.cpp b/src/Display/Lcd/ILI9488/ILI9488.cpp
index 016c6ed5..7fe8b8e1 100644
--- a/src/Display/Lcd/ILI9488/ILI9488.cpp
+++ b/src/Display/Lcd/ILI9488/ILI9488.cpp
@@ -12,8 +12,13 @@
 
 constexpr PwmFrequency BacklightPwmFrequency = 1000;
 
+#if USE_FONT_CHIP
+LcdILI9488::LcdILI9488(Pin fontCsPin, uint8_t sercomNum) noexcept
+	: TFTLcd(320, 480, fontCsPin, SpiMode::mode0, sercomNum)
+#else
 LcdILI9488::LcdILI9488(const LcdFont * const fnts[], size_t nFonts, uint8_t sercomNum) noexcept
 	: TFTLcd(320, 480, fnts, nFonts, SpiMode::mode0, sercomNum)
+#endif
 {
 }
 
diff --git a/src/Display/Lcd/ILI9488/ILI9488.h b/src/Display/Lcd/ILI9488/ILI9488.h
index 9b57ee6b..d5d37d42 100644
--- a/src/Display/Lcd/ILI9488/ILI9488.h
+++ b/src/Display/Lcd/ILI9488/ILI9488.h
@@ -15,8 +15,12 @@
 class LcdILI9488 : public TFTLcd
 {
 public:
-	// Construct a GLCD driver.
+	// Construct a GLCD driver
+#if USE_FONT_CHIP
+	LcdILI9488(Pin fontCsPin, uint8_t sercomNum) noexcept;
+#else
 	LcdILI9488(const LcdFont * const fnts[], size_t nFonts, uint8_t sercomNum) noexcept;
+#endif
 
 	~LcdILI9488();
 
diff --git a/src/Display/Lcd/Lcd.cpp b/src/Display/Lcd/Lcd.cpp
index f67f7c33..6eab8398 100644
--- a/src/Display/Lcd/Lcd.cpp
+++ b/src/Display/Lcd/Lcd.cpp
@@ -5,8 +5,14 @@
 
 #if SUPPORT_DIRECT_LCD
 
+#if USE_FONT_CHIP
+Lcd::Lcd(PixelNumber nr, PixelNumber nc, Pin fontCsPin) noexcept
+	: fontChip(fontCsPin),
+#else
 Lcd::Lcd(PixelNumber nr, PixelNumber nc, const LcdFont * const fnts[], size_t nFonts) noexcept
-	: numRows(nr), numCols(nc), fonts(fnts), numFonts(nFonts),
+	: fonts(fnts), numFonts(nFonts),
+#endif
+	  numRows(nr), numCols(nc),
 	  currentFontNumber(0), textInverted(false), numContinuationBytesLeft(0)
 {
 }
@@ -15,9 +21,19 @@ Lcd::~Lcd()
 {
 }
 
+// Return the number of fonts
+size_t Lcd::GetNumFonts() const noexcept
+{
+#if USE_FONT_CHIP
+	return fontChip.GetNumFonts();
+#else
+	return numFonts;
+#endif
+}
+
 void Lcd::SetFont(size_t newFont) noexcept
 {
-	if (newFont < numFonts)
+	if (newFont < GetNumFonts())
 	{
 		currentFontNumber = newFont;
 	}
@@ -26,17 +42,25 @@ void Lcd::SetFont(size_t newFont) noexcept
 // Get the current font height
 PixelNumber Lcd::GetFontHeight() const noexcept
 {
+#if USE_FONT_CHIP
+	return fontChip.GetFontHeight(currentFontNumber);
+#else
 	return fonts[currentFontNumber]->height;
+#endif
 }
 
 // Get the height of a specified font
 PixelNumber Lcd::GetFontHeight(size_t fontNumber) const noexcept
 {
-	if (fontNumber >= numFonts)
+	if (fontNumber >= GetNumFonts())
 	{
 		fontNumber = currentFontNumber;
 	}
+#if USE_FONT_CHIP
+	return fontChip.GetFontHeight(fontNumber);
+#else
 	return fonts[fontNumber]->height;
+#endif
 }
 
 // Write a UTF8 byte.
@@ -107,15 +131,19 @@ size_t Lcd::write(uint8_t c) noexcept
 
 size_t Lcd::writeNative(uint16_t ch) noexcept
 {
-	const LcdFont * const currentFont = fonts[currentFontNumber];
 	if (ch == '\n')
 	{
-		SetCursor(row + currentFont->height + 1, leftMargin);
+		SetCursor(row + GetFontHeight() + 1, leftMargin);
 	}
 	else
 	{
 		if (column < rightMargin)					// keep column <= rightMargin in the following code
 		{
+#if USE_FONT_CHIP
+			PixelNumber numFontColumns = fontChip.GetCharacter(currentFontNumber, ch);
+			const PixelNumber fontHeight = GetFontHeight();
+#else
+			const LcdFont * const currentFont = fonts[currentFontNumber];
 			const uint16_t startChar = currentFont->startCharacter;
 			const uint16_t endChar = currentFont->endCharacter;
 
@@ -128,22 +156,37 @@ size_t Lcd::writeNative(uint16_t ch) noexcept
 			const PixelNumber fontBytesPerColumn = (fontHeight + 7)/8;
 			const PixelNumber fontBytesPerChar = (fontBytesPerColumn * currentFont->width) + 1;
 			const uint8_t *fontPtr = currentFont->ptr + (fontBytesPerChar * (ch - startChar));
-			const uint32_t cmask = (currentFont->height < 32) ? (1u << currentFont->height) - 1 : 0xFFFFFFFF;
-
 			PixelNumber numFontColumns = *fontPtr++;
+#endif
+			const uint32_t cmask = (fontHeight < 32) ? (1u << fontHeight) - 1 : 0xFFFFFFFF;
 			PixelNumber columnsLeft = rightMargin - column;
 			PixelNumber numSpaces;
 			if (lastCharColData != 0)		// if we have written anything other than spaces
 			{
-				numSpaces = currentFont->numSpaces;
-
 				// Decide whether to add space columns first, and whether to add one less then usual (auto-kerning)
-				uint32_t thisCharColData = *reinterpret_cast<const uint32_t*>(fontPtr) & cmask;
+				uint32_t thisCharColData =
+#if USE_FONT_CHIP
+										fontChip.GetColumnData(0);
+#else
+										*reinterpret_cast<const uint32_t*>(fontPtr) & cmask;
+#endif
 				if (thisCharColData == 0)  // for characters with deliberate space column at the start, e.g. decimal point
 				{
-					thisCharColData = *reinterpret_cast<const uint32_t*>(fontPtr + fontBytesPerChar) & cmask;
+					thisCharColData =
+#if USE_FONT_CHIP
+										fontChip.GetColumnData(1);
+#else
+										*reinterpret_cast<const uint32_t*>(fontPtr + fontBytesPerChar) & cmask;
+#endif
 				}
 
+				numSpaces =
+#if USE_FONT_CHIP
+							fontChip.GetSpacing(currentFontNumber);
+#else
+							currentFont->numSpaces;
+#endif
+
 				const bool kern = (numSpaces >= 2)
 								? ((thisCharColData & lastCharColData) == 0)
 								: (((thisCharColData | (thisCharColData << 1)) & (lastCharColData | (lastCharColData << 1))) == 0);
@@ -184,10 +227,14 @@ size_t Lcd::writeNative(uint16_t ch) noexcept
 			}
 			column += numSpaces;
 
-			while (numFontColumns != 0)
+			for (PixelNumber charColumn = 0; charColumn < numFontColumns; ++charColumn)
 			{
+#if USE_FONT_CHIP
+				const uint32_t colData = fontChip.GetColumnData(charColumn);
+#else
 				const uint32_t colData = *reinterpret_cast<const uint32_t*>(fontPtr);
 				fontPtr += fontBytesPerColumn;
+#endif
 				if ((colData & cmask) != 0)
 				{
 					lastCharColData = colData & cmask;
@@ -196,7 +243,6 @@ size_t Lcd::writeNative(uint16_t ch) noexcept
 				{
 					WriteColumnData(ySize, colData);
 				}
-				--numFontColumns;
 				++column;
 			}
 			if (ySize != 0)
@@ -224,8 +270,7 @@ void Lcd::Clear(PixelNumber top, PixelNumber left, PixelNumber bottom, PixelNumb
 // Write some spaces
 void Lcd::WriteSpaces(PixelNumber numPixels) noexcept
 {
-	const LcdFont * const currentFont = fonts[currentFontNumber];
-	uint8_t ySize = currentFont->height;
+	uint8_t ySize = GetFontHeight();
 	if (row < numRows)
 	{
 		if (row + ySize > numRows)
diff --git a/src/Display/Lcd/Lcd.h b/src/Display/Lcd/Lcd.h
index d93042ca..5aa5a5fd 100644
--- a/src/Display/Lcd/Lcd.h
+++ b/src/Display/Lcd/Lcd.h
@@ -6,10 +6,15 @@
 #if SUPPORT_DIRECT_LCD
 
 #include <Print.h>
-#include "Fonts/LcdFont.h"
 #include <Hardware/Spi/SharedSpiClient.h>
 #include <General/SafeVsnprintf.h>
 
+#if USE_FONT_CHIP
+# include "Fonts/ER3301_1.h"
+#else
+# include "Fonts/LcdFont.h"
+#endif
+
 typedef uint16_t PixelNumber;
 
 struct Colour
@@ -38,7 +43,12 @@ class Lcd
 {
 public:
 	// Construct a GLCD driver.
+#if USE_FONT_CHIP
+	Lcd(PixelNumber nr, PixelNumber nc, Pin fontCsPin) noexcept;
+#else
 	Lcd(PixelNumber nr, PixelNumber nc, const LcdFont * const fnts[], size_t nFonts) noexcept;
+#endif
+
 	virtual ~Lcd();
 
 	// Flush just some data, returning true if this needs to be called again
@@ -109,7 +119,7 @@ public:
 	void WriteSpaces(PixelNumber numPixels) noexcept;
 
 	// Return the number of fonts
-	size_t GetNumFonts() const noexcept { return numFonts; }
+	size_t GetNumFonts() const noexcept;
 
 	// Get the current font height
 	PixelNumber GetFontHeight() const noexcept;
@@ -171,12 +181,17 @@ protected:
 	// Write a decoded character
 	size_t writeNative(uint16_t c) noexcept;
 
+#if USE_FONT_CHIP
+	ER3301_1 fontChip;
+#else
+	const LcdFont * const *_ecv_array fonts;
+	const size_t numFonts;
+#endif
+
 	const PixelNumber numRows, numCols;
 	PixelNumber row, column;
 	PixelNumber leftMargin, rightMargin;
 
-	const LcdFont * const *_ecv_array fonts;
-	const size_t numFonts;
 	size_t currentFontNumber = 0;					// index of the current font
 	bool textInverted = false;
 
diff --git a/src/Display/Lcd/TFTLcd.cpp b/src/Display/Lcd/TFTLcd.cpp
index 087bfa66..e69ad830 100644
--- a/src/Display/Lcd/TFTLcd.cpp
+++ b/src/Display/Lcd/TFTLcd.cpp
@@ -9,8 +9,13 @@
 
 #if SUPPORT_ILI9488_LCD
 
+#if USE_FONT_CHIP
+TFTLcd::TFTLcd(PixelNumber nr, PixelNumber nc, Pin fontCsPin, SpiMode mode, uint8_t sercomNum) noexcept
+	: Lcd(nr, nc, fontCsPin),
+#else
 TFTLcd::TFTLcd(PixelNumber nr, PixelNumber nc, const LcdFont * const fnts[], size_t nFonts, SpiMode mode, uint8_t sercomNum) noexcept
 	: Lcd(nr, nc, fnts, nFonts),
+#endif
 	  spiDev(sercomNum),
 	  fgColour(Colours::White), bgColour(Colours::Blue),
 	  spiMode(mode)
diff --git a/src/Display/Lcd/TFTLcd.h b/src/Display/Lcd/TFTLcd.h
index 531f13a6..1b4e635d 100644
--- a/src/Display/Lcd/TFTLcd.h
+++ b/src/Display/Lcd/TFTLcd.h
@@ -17,7 +17,12 @@
 class TFTLcd : public Lcd
 {
 public:
+#if USE_FONT_CHIP
+	TFTLcd(PixelNumber nr, PixelNumber nc, Pin fontCsPin, SpiMode mode, uint8_t sercomNum) noexcept;
+#else
 	TFTLcd(PixelNumber nr, PixelNumber nc, const LcdFont * const fnts[], size_t nFonts, SpiMode mode, uint8_t sercomNum) noexcept;
+#endif
+
 	virtual ~TFTLcd();
 
 	// Get the SPI frequency