antonio cristiano
ok
Fork of
TextLCD
by 
Wim Huiskamp
Revision 14:0c32b66b14b8, committed 2013-02-10
- Comitter:
- wim
- Date:
- Sun Feb 10 18:43:51 2013 +0000
- Parent:
- 13:24506ba22480
- Child:
- 15:b70ebfffb258
- Commit message:
- Added support for I2C and SPI bus interfaces
Changed in this revision
| TextLCD.cpp | Show annotated file Show diff for this revision Revisions of this file |
| TextLCD.h | Show annotated file Show diff for this revision Revisions of this file |
--- a/TextLCD.cpp Sat Feb 09 15:10:36 2013 +0000
+++ b/TextLCD.cpp Sun Feb 10 18:43:51 2013 +0000
@@ -1,6 +1,7 @@
/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
* Copyright (c) 2007-2010, sford, http://mbed.org
- * 2013, WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs
+ * 2013, v01: WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs
+ * 2013, v02: WH, Added I2C and SPI bus interfaces
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@@ -28,6 +29,7 @@
PinName d4, PinName d5, PinName d6, PinName d7,
LCDType type): _rs(rs), _e(e),
_d(d4, d5, d6, d7),
+ _cs(NC),
_type(type) {
@@ -40,6 +42,7 @@
TextLCD::TextLCD(I2C *i2c, char deviceAddress, LCDType type) :
_rs(NC), _e(NC), _d(NC),
+ _cs(NC),
_i2c(i2c),
_type(type) {
@@ -57,7 +60,36 @@
}
-/** Init the LCD controller
+
+TextLCD::TextLCD(SPI *spi, PinName cs, LCDType type) :
+ _rs(NC), _e(NC), _d(NC),
+ _spi(spi),
+ _cs(cs),
+ _type(type) {
+
+ _busType = _SPIBus;
+
+ // Setup the spi for 8 bit data, low steady state clock,
+ // rising edge capture, with a 500KHz or 1MHz clock rate
+ _spi->format(8,0);
+ _spi->frequency(500000);
+ //_spi.frequency(1000000);
+
+
+ // Init the portexpander bus
+ _lcd_bus = 0x80;
+
+ // write the new data to the portexpander
+ _setCS(false);
+ _spi->write(_lcd_bus);
+ _setCS(true);
+
+ _init();
+
+}
+
+
+/* Init the LCD controller
* 4-bit mode, number of lines, no cursor etc
* Clear display
*/
@@ -68,16 +100,19 @@
_setEnable(true);
_setRS(false); // command mode
- wait(0.015); // Wait 15ms to ensure powered up
+// wait(0.015); // Wait 15ms to ensure powered up
+ wait_ms(15); // Wait 15ms to ensure powered up
// send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
for (int i=0; i<3; i++) {
_writeByte(0x3);
- wait(0.00164); // this command takes 1.64ms, so wait for it
+// wait(0.00164); // this command takes 1.64ms, so wait for it
+ wait_ms(10); // this command takes 1.64ms, so wait for it
}
_writeByte(0x2); // 4-bit mode
- wait(0.000040f); // most instructions take 40us
-
+// wait(0.000040f); // most instructions take 40us
+ wait_us(40); // most instructions take 40us
+
// Display is now in 4-bit mode
switch (_type) {
case LCD8x1:
@@ -144,7 +179,9 @@
void TextLCD::cls() {
_writeCommand(0x01); // cls, and set cursor to 0
- wait(0.00164f); // This command takes 1.64 ms
+// wait(0.00164f); // This command takes 1.64 ms
+ wait_ms(10); // The CLS command takes 1.64 ms.
+ // Since we are not using the Busy flag, Lets be safe and take 10 ms
locate(0, 0);
}
@@ -191,17 +228,27 @@
break;
case _I2CBus :
- if (value)
- _lcd_bus |= D_LCD_E; // Set E bit
- else
- _lcd_bus &= ~D_LCD_E; // Reset E bit
+ if (value)
+ _lcd_bus |= D_LCD_E; // Set E bit
+ else
+ _lcd_bus &= ~D_LCD_E; // Reset E bit
- // write the new data to the portexpander
- _i2c->write(_slaveAddress, &_lcd_bus, 1);
+ // write the new data to the portexpander
+ _i2c->write(_slaveAddress, &_lcd_bus, 1);
break;
case _SPIBus :
+ if (value)
+ _lcd_bus |= D_LCD_E; // Set E bit
+ else
+ _lcd_bus &= ~D_LCD_E; // Reset E bit
+
+ // write the new data to the portexpander
+ _setCS(false);
+ _spi->write(_lcd_bus);
+ _setCS(true);
+
break;
}
}
@@ -218,17 +265,27 @@
break;
case _I2CBus :
- if (value)
- _lcd_bus |= D_LCD_RS; // Set RS bit
- else
- _lcd_bus &= ~D_LCD_RS; // Reset RS bit
+ if (value)
+ _lcd_bus |= D_LCD_RS; // Set RS bit
+ else
+ _lcd_bus &= ~D_LCD_RS; // Reset RS bit
- // write the new data to the portexpander
- _i2c->write(_slaveAddress, &_lcd_bus, 1);
+ // write the new data to the portexpander
+ _i2c->write(_slaveAddress, &_lcd_bus, 1);
break;
case _SPIBus :
+ if (value)
+ _lcd_bus |= D_LCD_RS; // Set RS bit
+ else
+ _lcd_bus &= ~D_LCD_RS; // Reset RS bit
+
+ // write the new data to the portexpander
+ _setCS(false);
+ _spi->write(_lcd_bus);
+ _setCS(true);
+
break;
}
@@ -271,28 +328,70 @@
break;
case _SPIBus :
- break;
+
+ data = value & 0x0F;
+ if (data & 0x01)
+ _lcd_bus |= D_LCD_D4; // Set Databit
+ else
+ _lcd_bus &= ~D_LCD_D4; // Reset Databit
+
+ if (data & 0x02)
+ _lcd_bus |= D_LCD_D5; // Set Databit
+ else
+ _lcd_bus &= ~D_LCD_D5; // Reset Databit
+
+ if (data & 0x04)
+ _lcd_bus |= D_LCD_D6; // Set Databit
+ else
+ _lcd_bus &= ~D_LCD_D6; // Reset Databit
+
+ if (data & 0x08)
+ _lcd_bus |= D_LCD_D7; // Set Databit
+ else
+ _lcd_bus &= ~D_LCD_D7; // Reset Databit
+
+ // write the new data to the portexpander
+ _setCS(false);
+ _spi->write(_lcd_bus);
+ _setCS(true);
+
+ break;
}
}
+// Set CS line. Only used for SPI bus
+void TextLCD::_setCS(bool value) {
+
+ if (value)
+ _cs = 1; // Set CS pin
+ else
+ _cs = 0; // Reset CS pin
+
+}
+
+
void TextLCD::_writeByte(int value) {
// _d = value >> 4;
_setData(value >> 4);
- wait(0.000040f); // most instructions take 40us
+// wait(0.000040f); // most instructions take 40us
+ wait_us(40); // most instructions take 40us
// _e = 0;
_setEnable(false);
- wait(0.000040f);
+// wait(0.000040f);
+ wait_us(40); // most instructions take 40us
// _e = 1;
_setEnable(true);
// _d = value >> 0;
_setData(value >> 0);
- wait(0.000040f);
+// wait(0.000040f);
+ wait_us(40); // most instructions take 40us
// _e = 0;
_setEnable(false);
- wait(0.000040f); // most instructions take 40us
+// wait(0.000040f); // most instructions take 40us
+ wait_us(40); // most instructions take 40us
// _e = 1;
_setEnable(true);
}
--- a/TextLCD.h Sat Feb 09 15:10:36 2013 +0000
+++ b/TextLCD.h Sun Feb 10 18:43:51 2013 +0000
@@ -166,7 +166,7 @@
* @param cs chip select pin (active low)
* @param type Sets the panel size/addressing mode (default = LCD16x2)
*/
-// TextLCD(SPI *spi, PinName cs, LCDType type = LCD16x2);
+ TextLCD(SPI *spi, PinName cs, LCDType type = LCD16x2);
#if DOXYGEN_ONLY
@@ -239,11 +239,11 @@
void setUDC(unsigned char c, char *udc_data);
protected:
- /** LCD Bus control */
+ /* LCD Bus control */
enum _LCDBus {
- _PinBus, /**< Regular mbed pins */
- _I2CBus, /**< I2C PCF8574 Portexpander */
- _SPIBus /**< SPI 74595 */
+ _PinBus, /*< Regular mbed pins */
+ _I2CBus, /*< I2C PCF8574 Portexpander */
+ _SPIBus /*< SPI 74595 */
};
// Stream implementation functions
@@ -258,7 +258,8 @@
void _setEnable(bool value);
void _setRS(bool value);
void _setData(int value);
-
+ void _setCS(bool value);
+
//Low level writes to LCD serial bus only
void _writeBus();
@@ -276,8 +277,8 @@
unsigned char _slaveAddress;
// SPI bus
-// SPI *_spi;
-// DigitalOut _cs;
+ SPI *_spi;
+ DigitalOut _cs;
//Bus Interface type
_LCDBus _busType;