Wim Huiskamp
Updated for more display types. Fixed memoryaddress confusion in address() method. Added new getAddress() method. Added support for UDCs, Backlight control and other features such as control through I2C and SPI port expanders and controllers with native I2C and SPI interfaces. Refactored to fix issue with pins that are default declared as NC.
Dependents: GPSDevice TestTextLCD SD to Flash Data Transfer DrumMachine ... more
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TextLCD
by 
Simon Ford
Example
Hello World! for the TextLCD
#include "mbed.h"
#include "TextLCD.h"
// Host PC Communication channels
Serial pc(USBTX, USBRX); // tx, rx
// I2C Communication
I2C i2c_lcd(p28,p27); // SDA, SCL
// SPI Communication
SPI spi_lcd(p5, NC, p7); // MOSI, MISO, SCLK
//TextLCD lcd(p15, p16, p17, p18, p19, p20); // RS, E, D4-D7, LCDType=LCD16x2, BL=NC, E2=NC, LCDTCtrl=HD44780
//TextLCD_SPI lcd(&spi_lcd, p8, TextLCD::LCD40x4); // SPI bus, 74595 expander, CS pin, LCD Type
TextLCD_I2C lcd(&i2c_lcd, 0x42, TextLCD::LCD20x4); // I2C bus, PCF8574 Slaveaddress, LCD Type
//TextLCD_I2C lcd(&i2c_lcd, 0x42, TextLCD::LCD16x2, TextLCD::WS0010); // I2C bus, PCF8574 Slaveaddress, LCD Type, Device Type
//TextLCD_SPI_N lcd(&spi_lcd, p8, p9); // SPI bus, CS pin, RS pin, LCDType=LCD16x2, BL=NC, LCDTCtrl=ST7032_3V3
//TextLCD_I2C_N lcd(&i2c_lcd, ST7032_SA, TextLCD::LCD16x2, NC, TextLCD::ST7032_3V3); // I2C bus, Slaveaddress, LCD Type, BL=NC, LCDTCtrl=ST7032_3V3
int main() {
pc.printf("LCD Test. Columns=%d, Rows=%d\n\r", lcd.columns(), lcd.rows());
for (int row=0; row<lcd.rows(); row++) {
int col=0;
pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));
// lcd.putc('-');
lcd.putc('0' + row);
for (col=1; col<lcd.columns()-1; col++) {
lcd.putc('*');
}
pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));
lcd.putc('+');
}
// Show cursor as blinking character
lcd.setCursor(TextLCD::CurOff_BlkOn);
// Set and show user defined characters. A maximum of 8 UDCs are supported by the HD44780.
// They are defined by a 5x7 bitpattern.
lcd.setUDC(0, (char *) udc_0); // Show |>
lcd.putc(0);
lcd.setUDC(1, (char *) udc_1); // Show <|
lcd.putc(1);
}
Handbook page
More info is here
Diff: TextLCD.cpp
- Revision:
- 27:22d5086f6ba6
- Parent:
- 26:bd897a001012
- Child:
- 28:30fa94f7341c
--- a/TextLCD.cpp Fri May 30 15:05:13 2014 +0000
+++ b/TextLCD.cpp Fri Jun 13 19:02:26 2014 +0000
@@ -49,28 +49,25 @@
// Select and configure second LCD controller when needed
if(_type==LCD40x4) {
- _ctrl_idx=_LCDCtrl_1; // Select 2nd controller
+ _ctrl_idx=_LCDCtrl_1; // Select 2nd controller
- _initCtrl(); // Init 2nd controller
+ _initCtrl(); // Init 2nd controller
// Secondary LCD controller Clearscreen
- _writeCommand(0x01); // cls, and set cursor to 0
+ _writeCommand(0x01); // cls, and set cursor to 0
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
-
+ // Since we are not using the Busy flag, Lets be safe and take 10 ms
}
// Select and configure primary LCD controller
- _ctrl_idx=_LCDCtrl_0; // Select primary controller
+ _ctrl_idx=_LCDCtrl_0; // Select primary controller
_initCtrl(); // Init primary controller
// Primary LCD controller Clearscreen
- _writeCommand(0x01); // cls, and set cursor to 0
-
+ _writeCommand(0x01); // cls, and set cursor to 0
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
-
+ // Since we are not using the Busy flag, Lets be safe and take 10 ms
}
/** Init the LCD controller
@@ -92,54 +89,68 @@
wait_us(40); // most instructions take 40us
// Display is now in 4-bit mode
+ // Note: 4 bit mode is ignored for native SPI and I2C devices
// Device specific initialisations for DC/DC converter to generate VLCD or VLED
switch (_ctrl) {
case ST7036:
// ST7036 controller: Initialise Voltage booster for VLCD. VDD=5V
// Note: supports 1,2 or 3 lines
- _writeByte( 0x29 ); // 4-bit Databus, 2 Lines, Select Instruction table 1
+ _writeByte( 0x29 ); // 4-bit Databus, 2 Lines, Select Instruction Set = 1
wait_ms(30); // > 26,3ms
_writeByte( 0x14 ); // Bias: 1/5, 2-Lines LCD
wait_ms(30); // > 26,3ms
_writeByte( 0x55 ); // Icon off, Booster on, Set Contrast C5, C4
wait_ms(30); // > 26,3ms
- _writeByte( 0x6d ); // Voltagefollower On, Ampl ratio Rab2, Rab1, Rab0
+ _writeByte( 0x6D ); // Voltagefollower On, Ampl ratio Rab2, Rab1, Rab0
wait_ms(200); // > 200ms!
_writeByte( 0x78 ); // Set Contrast C3, C2, C1, C0
wait_ms(30); // > 26,3ms
- _writeByte( 0x28 ); // Return to Instruction table 0
+ _writeByte( 0x28 ); // Return to Instruction Set = 0
wait_ms(50);
break;
case ST7032_3V3:
// ST7032 controller: Initialise Voltage booster for VLCD. VDD=3V3
-
- _writeByte( 0x1c ); //Internal OSC frequency adjustment 183HZ, bias will be 1/4
+
+// _writeByte( 0x39 ); //FUNCTION SET 8 bit,N=1 2-line display mode,5*7dot, Select Instruction Set = 1
+ _writeByte( 0x29 ); //FUNCTION SET 4 bit, N=1 2-line display mode, 5*7dot, Select Instruction Set = 1
+ //Note: 4 bit mode is ignored for native SPI and I2C devices
+ wait_us(30);
+ _writeByte( 0x1C ); //Internal OSC frequency adjustment 183HZ, bias will be 1/4
wait_us(30);
_writeByte( 0x73 ); //Contrast control low byte
wait_us(30);
_writeByte( 0x57 ); //booster circuit is turned on. /ICON display off. /Contrast control high byte
wait_us(30);
- _writeByte( 0x6c ); //Follower control
+ _writeByte( 0x6C ); //Follower control
wait_us(50);
- _writeByte( 0x0c ); //DISPLAY ON, not needed
+// _writeByte( 0x0C ); //DISPLAY ON, not needed
+// _writeByte( 0x38 ); //FUNCTION SET 8 bit,N=1 2-line display mode,5*7dot, Return to Instruction Set = 0
+ _writeByte( 0x28 ); //FUNCTION SET 4 bit, N=1 2-line display mode, 5*7dot, Return to Instruction Set = 0
+ //Note: 4 bit mode is ignored for native SPI and I2C devices
wait_us(30);
break;
//Check and fix booster disable
case ST7032_5V:
// ST7032 controller: Disable Voltage booster for VLCD. VDD=5V
-
- _writeByte( 0x1c ); //Internal OSC frequency adjustment 183HZ, bias will be 1/4
+// _writeByte( 0x39 ); //FUNCTION SET 8 bit,N=1 2-line display mode,5*7dot, Instruction Set = 1
+ _writeByte( 0x29 ); //FUNCTION SET 4 bit, N=1 2-line display mode, 5*7dot, Select Instruction Set = 1
+ //Note: 4 bit mode is ignored for native SPI and I2C devices
+ wait_us(30);
+ _writeByte( 0x1C ); //Internal OSC frequency adjustment 183HZ, bias will be 1/4
wait_us(30);
_writeByte( 0x73 ); //Contrast control low byte
wait_us(30);
_writeByte( 0x57 ); //booster circuit is turned on. /ICON display off. /Contrast control high byte
wait_us(30);
- _writeByte( 0x6c ); //Follower control
+ _writeByte( 0x6C ); //Follower control
wait_us(50);
- _writeByte( 0x0c ); //DISPLAY ON --> remove, done later?
+// _writeByte( 0x0C ); //DISPLAY ON --> remove, done later?
+// _writeByte( 0x38 ); //FUNCTION SET 8 bit,N=1 2-line display mode,5*7dot, Instruction Set = 0
+ _writeByte( 0x28 ); //FUNCTION SET 4 bit, N=1 2-line display mode, 5*7dot, Return to Instruction Set = 0
+ //Note: 4 bit mode is ignored for native SPI and I2C devices
wait_us(30);
break;
@@ -208,7 +219,8 @@
// All other LCD types are initialised as 2 Line displays (including LCD40x4)
default:
_writeCommand(0x28); // Function set 001 DL N F - -
- // DL=0 (4 bits bus)
+ // DL=0 (4 bits bus)
+ // Note: 4 bit mode is ignored for native SPI and I2C devices
// N=1 (2 lines)
// F=0 (5x7 dots font, only option for 2 line display)
// - (Don't care)
@@ -240,8 +252,7 @@
_setCursorAndDisplayMode(_currentMode, CurOff_BlkOff);
// Second LCD controller Clearscreen
- _writeCommand(0x01); // cls, and set cursor to 0
-
+ _writeCommand(0x01); // cls, and set cursor to 0
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
@@ -250,8 +261,7 @@
}
// Primary LCD controller Clearscreen
- _writeCommand(0x01); // cls, and set cursor to 0
-
+ _writeCommand(0x01); // cls, and set cursor to 0
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
@@ -893,17 +903,17 @@
#if (MCP23008==1)
// MCP23008 portexpander Init
- _write_register(IODIR, 0x00); // All outputs
- _write_register(IPOL, 0x00); // No reverse polarity
- _write_register(GPINTEN, 0x00); // No interrupt
- _write_register(DEFVAL, 0x00); // Default value to compare against for interrupts
- _write_register(INTCON, 0x00); // No interrupt on changes
- _write_register(IOCON, 0x00); // Interrupt polarity
- _write_register(GPPU, 0x00); // No Pullup
- _write_register(INTF, 0x00); //
- _write_register(INTCAP, 0x00); //
- _write_register(GPIO, 0x00); // Output/Input pins
- _write_register(OLAT, 0x00); // Output Latch
+ _write_register(IODIR, 0x00); // All outputs
+ _write_register(IPOL, 0x00); // No reverse polarity
+ _write_register(GPINTEN, 0x00); // No interrupt
+ _write_register(DEFVAL, 0x00); // Default value to compare against for interrupts
+ _write_register(INTCON, 0x00); // No interrupt on changes
+ _write_register(IOCON, 0x00); // Interrupt polarity
+ _write_register(GPPU, 0x00); // No Pullup
+ _write_register(INTF, 0x00); //
+ _write_register(INTCAP, 0x00); //
+ _write_register(GPIO, 0x00); // Output/Input pins
+ _write_register(OLAT, 0x00); // Output Latch
// Init the portexpander bus
_lcd_bus = D_LCD_BUS_DEF;
@@ -1264,8 +1274,6 @@
_bl = NULL; //Construct dummy pin
}
- _writeByte( 0x39 ); //FUNCTION SET 8 bit,N=1 2-line display mode,5*7dot IS=1
- wait_us(30);
_init();
}
HD44780 and compatible Text LCD controllers (4bit, I2C or SPI I/F)