X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=firmware%2Flcd.c;fp=firmware%2Flcd.c;h=8c722d8d29e7e9150d83c76ee9eb63f04e22fb2a;hb=d8a31ed675778c08ca781beb62863c62d6f0bd94;hp=0000000000000000000000000000000000000000;hpb=af6a469f761ceec44e94bea5fe8e5345fd368966;p=model-railway-devices.git

diff --git a/firmware/lcd.c b/firmware/lcd.c
new file mode 100644
index 0000000..8c722d8
--- /dev/null
+++ b/firmware/lcd.c
@@ -0,0 +1,83 @@
+#include <avr/io.h>
+#include <util/delay.h>
+
+#define USE_SHIFTREG 1
+
+#define NOP() __asm__("nop")
+
+void lcd_init(void);
+void lcd_on(void);
+void lcd_clear(void);
+void lcd_goto(uint8_t);
+void lcd_write(uint8_t);
+
+void lcd_clock(void)
+{
+	_delay_us(1);
+	PORTB |= 0x02;
+	_delay_us(1);
+	PORTB &= ~0x02;
+}
+
+void lcd_set_data(uint8_t d)
+{
+#ifdef USE_SHIFTREG
+	uint8_t i;
+	for(i=0; i<8; ++i)
+	{
+		PORTB = (PORTB&~0x04)|((d&1)<<2);
+		PORTB |= 0x08;
+		NOP();
+		PORTB &= ~0x08;
+		d >>= 1;
+	}
+#else
+	PORTD = (PORTD&0x3F) | (d<<6);
+	PORTB = (PORTB&0xC0) | (d>>2);
+#endif
+}
+
+void lcd_command(uint8_t c)
+{
+	PORTB &= ~0x01;
+	lcd_set_data(c);
+	lcd_clock();
+}
+
+void lcd_init(void)
+{
+	DDRB |= 0x0F;
+	PORTB &= ~0x0F;
+	_delay_ms(20);
+	lcd_command(0x38);
+	_delay_us(50);
+}
+
+void lcd_on(void)
+{
+	lcd_command(0x0C);
+	_delay_us(50);
+}
+
+void lcd_clear(void)
+{
+	lcd_command(0x01);
+	_delay_us(1500);
+}
+
+void lcd_gotoxy(uint8_t x, uint8_t y)
+{
+	uint8_t a = x+10*y;
+	if(y&1)
+		a += 54;
+	lcd_command(a|0x80);
+	_delay_us(50);
+}
+
+void lcd_write(uint8_t c)
+{
+	PORTB |= 0x01;
+	lcd_set_data(c);
+	lcd_clock();
+	_delay_us(50);
+}