From a9b4431d67bebe8bb44d937e30179224b1a51f27 Mon Sep 17 00:00:00 2001
From: "Christian L. V. Madsen" <christian@oz1cm.dk>
Date: Wed, 18 Jun 2025 16:15:19 +0200
Subject: [PATCH] works now and is tested.. but needs cleanup!!

---
 lcd_hd44780.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++---
 lcd_hd44780.h |  6 +++++
 2 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/lcd_hd44780.c b/lcd_hd44780.c
index 63cca46..1a880e1 100644
--- a/lcd_hd44780.c
+++ b/lcd_hd44780.c
@@ -72,14 +72,12 @@ static int lcd_write_8bit(cm_lcd_hd44780_t *inst, uint8_t dataOrCmd, hd44780_Ins
 	// Then Clock data in with  E pin. Data is clocked on Falling edge:
 	inst->gpio_data.e_pin = 0;
 	inst->setGetGpio_event(&(inst->gpio_data),LCD_HD44780_SET);
-
 	// Wait until display is ready:
 	WaitUntilReady(inst);
 
 	// Then set E pin high so its ready for next time:
 	inst->gpio_data.e_pin = 1;
 	inst->setGetGpio_event(&(inst->gpio_data),LCD_HD44780_SET);
-
 	return 0;
 
 }
@@ -101,15 +99,74 @@ static void lcd_writeCmd_disp(cm_lcd_hd44780_t *inst, hd44780_cmd_t cmd, hd44780
 
 }
 
+void lcd_hd44780_printChar(cm_lcd_hd44780_t *inst, char character) {
+	if (inst->bit_mode == LCD_HD44780_BITMODE_8BIT) {
+		lcd_write_8bit(inst, character, LCD_HD44780_DATA);
+		} else {
+		// Write MSB first
+		lcd_write_8bit(inst, ((character >> 4) & 0x0F) << 4, LCD_HD44780_DATA);
+		// Then LSB
+		lcd_write_8bit(inst, (character & 0x0F) << 4, LCD_HD44780_DATA);
+	}
+}
+
+void lcd_hd44780_printf(cm_lcd_hd44780_t *inst, char *string) {
+	while (*string) {
+		lcd_hd44780_printChar(inst, *string++);
+	}
+}
+
+void lcd_hd44780_print_xy(cm_lcd_hd44780_t *inst, uint8_t x, uint8_t y, const char *str) {
+	// Base DDRAM addresses for each row (for 2-line display)
+	const uint8_t row_offsets[] = {0x00, 0x40, 0x14, 0x54}; // for 4-line displays
+
+	if (y > 3) return;  // Prevent invalid row access
+
+	// Set DDRAM address command: 0x80 | (offset + x)
+	lcd_writeCmd_disp(inst, 0x80 | (row_offsets[y] + x), LCD_HD44780_SET);
+
+	// Write characters
+	while (*str) {
+		lcd_hd44780_printChar(inst, *str++);
+	}
+}
+
+void lcd_hd44780_cursorHome(cm_lcd_hd44780_t *inst) {
+	lcd_writeCmd_disp(inst, LCD_HD44780_RETURN_HOME, LCD_HD44780_SET);
+}
+
+void lcd_hd44780_clearDisp(cm_lcd_hd44780_t *inst) {
+	
+	lcd_writeCmd_disp(inst, LCD_HD44780_CLEAR_DISP, LCD_HD44780_SET);
+
+	// Wait for the command to finish.
+	// This is a long operation (? 1.53 ms), so if not polling BF, delay at least 2 ms.
+	if (!inst->isInit) {
+		inst->wait_event(2);
+		} else {
+		WaitUntilReady(inst);
+	}
+}
+
+
 void lcd_hd44780_initDisp(cm_lcd_hd44780_t *inst){
 
 	// Make sure E pin is high when data isnt ready on BUS!
 	inst->gpio_data.e_pin = 1;
 	inst->setGetGpio_event(&(inst->gpio_data),LCD_HD44780_SET);
+	inst->wait_event(1);
 
 	// Wait for more than 15ms after VCC rise..
 	inst->wait_event(15);
 	lcd_writeCmd_disp(inst, LCD_HD44780_FUNCTION_SET,LCD_HD44780_SET);
+	
+	// Init display to 4 bit mode if selected!
+	if(inst->bit_mode == LCD_HD44780_BITMODE_4BIT){
+		
+		lcd_write_8bit(inst, 0x20, LCD_HD44780_INSTRUCTION);
+		inst->wait_event(1);  // Small delay
+	}
+
 
 	// Wait for 4.1ms..
 	// Delay(4)
@@ -123,7 +180,7 @@ void lcd_hd44780_initDisp(cm_lcd_hd44780_t *inst){
 	lcd_writeCmd_disp(inst, LCD_HD44780_ENTRY_MODE,LCD_HD44780_SET);
 
 	// Init has been done, and we can now use Busy Flag polling instead of delay!
-	inst->isInit = 0x1;
+	//inst->isInit = 0x1;
 
 }
 
@@ -150,6 +207,8 @@ void lcd_hd44780_init(cm_lcd_hd44780_t *inst, lcd_hd44780_bitmode bit_mode){
 
 	inst->bit_mode = bit_mode;
 	lcd_hd44780_initDisp(inst);
+	
+	lcd_hd44780_clearDisp(inst);
 
 	return;
 }
diff --git a/lcd_hd44780.h b/lcd_hd44780.h
index f32f126..1d847e7 100644
--- a/lcd_hd44780.h
+++ b/lcd_hd44780.h
@@ -23,9 +23,11 @@ typedef enum {
 	LCD_HD44780_RETURN_HOME = 0x2,
 	LCD_HD44780_ENTRY_MODE = 0x6,
 	LCD_HD44780_DISP_ONOFF_CTL = 0xE,
+	LCD_HD44780_DISPLAY_ON_CURSOR_ON_BLINK_ON = 0x0F,
 	LCD_HD44780_CURSOR_SHIFT = 0x6,
 	LCD_HD44780_FUNCTION_SET = 0x30,
 	
+	
 }hd44780_cmd_t;
 
 typedef enum{
@@ -86,5 +88,9 @@ typedef struct{
 void lcd_hd44780_init(cm_lcd_hd44780_t *inst,lcd_hd44780_bitmode bit_mode);
 void lcd_hd44780_regGpioEvt(cm_lcd_hd44780_t *inst, setGet_Gpio_Event_fpt getGpioEvt_fpt);
 void lcd_hd44780_regWaitEvt(cm_lcd_hd44780_t *inst, wait_ms_Event_fpt waitEvt_fpt);
+void lcd_hd44780_cursorHome(cm_lcd_hd44780_t *inst);
+void lcd_hd44780_printf(cm_lcd_hd44780_t *inst, char *string);
+void lcd_hd44780_clearDisp(cm_lcd_hd44780_t *inst);
+void lcd_hd44780_print_xy(cm_lcd_hd44780_t *inst, uint8_t x, uint8_t y, const char *str);
 
 #endif /*LCD_HD44780_H_*/