added test lcd project

Microcontrollers/testlcd/main.c

@@ -0,0 +1,200 @@
+/* ---------------------------------------------------------------------------
+** This software is in the public domain, furnished "as is", without technical
+** support, and with no warranty, express or implied, as to its usefulness for
+** any purpose.
+**
+** ioisr.c
+**
+** Beschrijving:	BigAVR LCD module
+** Target:			AVR mcu
+** Build:			avr-gcc -std=c99 -Wall -O3 -mmcu=atmega128 -D F_CPU=8000000UL -c lcd.c
+**					avr-gcc -g -mmcu=atmega128 -o lcd.elf lcd.o
+**					avr-objcopy -O ihex lcd.elf lcd.hex
+**					or type 'make'
+** Author: 			dkroeske@gmail.com
+** -------------------------------------------------------------------------*/
+
+#define F_CPU 8e6
+
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/interrupt.h>
+
+#define LCD_E 	6  // RA6 UNI-6
+#define LCD_RS	4  // RA4 UNI-6
+
+void lcd_strobe_lcd_e(void);
+void init_4bits_mode(void);
+void lcd_write_string(char *str);
+void lcd_write_data(unsigned char byte);
+void lcd_write_cmd(unsigned char byte);
+void lcd_clear(void);
+
+
+/******************************************************************
+short:			Busy wait number of millisecs
+inputs:			int ms (Number of millisecs to busy wait)
+outputs:
+notes:			Busy wait, not very accurate. Make sure (external)
+clock value is set. This is used by _delay_ms inside
+util/delay.h
+Version :    	DMK, Initial code
+*******************************************************************/
+void wait( int ms ) {
+	for (int i=0; i<ms; i++) {
+		_delay_ms( 1 );		// library function (max 30 ms at 8MHz)
+	}
+}
+
+/******************************************************************
+short:			Strobe LCD module E pin --__
+inputs:
+outputs:
+notes:			According datasheet HD44780
+Version :    	DMK, Initial code
+*******************************************************************/
+void lcd_strobe_lcd_e(void) {
+	PORTA |= (1<<LCD_E);	// E high
+	_delay_ms(1);			// nodig
+	PORTA &= ~(1<<LCD_E);  	// E low
+	_delay_ms(1);			// nodig?
+}
+
+
+
+/******************************************************************
+short:			Init LCD module in 4 bits mode.
+inputs:
+outputs:
+notes:			According datasheet HD44780 table 12
+Version :    	DMK, Initial code
+*******************************************************************/
+void init_4bits_mode(void) {
+	// PORTC output mode and all low (also E and RS pin)
+	DDRD = 0xFF;
+	DDRA = 0xFF;
+	PORTC = 0x00;
+	PORTA = 0x00;
+	//PORTA = 0xFF;
+
+	// Step 2 (table 12)
+	PORTC = 0x20;	// function set
+	lcd_strobe_lcd_e();
+
+	// Step 3 (table 12)
+	PORTC = 0x20;   // function set
+	lcd_strobe_lcd_e();
+	PORTC = 0x80;
+	lcd_strobe_lcd_e();
+
+	// Step 4 (table 12)
+	PORTC = 0x00;   // Display on/off control
+	lcd_strobe_lcd_e();
+	PORTC = 0xF0;
+	lcd_strobe_lcd_e();
+
+	// Step 4 (table 12)
+	PORTC = 0x00;   // Entry mode set
+	lcd_strobe_lcd_e();
+	PORTC = 0x60;
+	lcd_strobe_lcd_e();
+}
+
+/******************************************************************
+short:			Writes string to LCD at cursor position
+inputs:
+outputs:
+notes:			According datasheet HD44780 table 12
+Version :    	DMK, Initial code
+*******************************************************************/
+void lcd_write_string(char *str) {
+	// Het kan met een while:
+
+	// while(*str) {
+	// 	lcd_write_data(*str++);
+	// }
+
+	// of met een for:
+	for(;*str; str++){
+		lcd_write_data(*str);
+	}
+}
+
+
+/******************************************************************
+short:			Writes 8 bits DATA to lcd
+inputs:			byte - written to LCD
+outputs:
+notes:			According datasheet HD44780 table 12
+Version :    	DMK, Initial code
+*******************************************************************/
+void lcd_write_data(unsigned char byte) {
+	// First nibble.
+	PORTC = byte;
+	PORTA |= (1<<LCD_RS);
+	lcd_strobe_lcd_e();
+
+	// Second nibble
+	PORTC = (byte<<4);
+	PORTA |= (1<<LCD_RS);
+	lcd_strobe_lcd_e();
+}
+
+/******************************************************************
+short:			Writes 8 bits COMMAND to lcd
+inputs:			byte - written to LCD
+outputs:
+notes:			According datasheet HD44780 table 12
+Version :    	DMK, Initial code
+*******************************************************************/
+void lcd_write_command(unsigned char byte) {
+	// First nibble.
+	PORTC = byte;
+	PORTA &= ~(1<<LCD_RS);
+	lcd_strobe_lcd_e();
+
+	// Second nibble
+	PORTC = (byte<<4);
+	PORTA &= ~(1<<LCD_RS);
+	lcd_strobe_lcd_e();
+}
+
+
+void lcd_clear() {
+	lcd_write_command (0x01);						//Leeg display
+	_delay_ms(2);
+	lcd_write_command (0x80);						//Cursor terug naar start
+}
+
+
+/******************************************************************
+short:			main() loop, entry point of executable
+inputs:
+outputs:
+notes:			Slow background task after init ISR
+Version :    	DMK, Initial code
+*******************************************************************/
+int main( void ) {
+	// Init I/O
+	DDRC = 0xFF;			// PORTD(7) output, PORTD(6:0) input
+	PORTC = 0xFF;
+
+	// Init LCD
+	init_4bits_mode();
+	
+	_delay_ms(10);
+	
+	lcd_clear();
+
+	// Write sample string
+	lcd_write_string("Hello world!");
+
+	// Loop forever
+	while (1) {
+		PORTC ^= (1<<0);	// Toggle PORTD.7
+		wait( 250 );
+		
+	}
+
+	return 1;
+}