From ecd33bd78e0caef597d3bad272ac239ffda74d24 Mon Sep 17 00:00:00 2001
From: root <root@fedora-arm.domain.avtechpulse.com>
Date: Fri, 31 Dec 1999 19:51:10 -0500
Subject: first LCD support

---
 lcd.c | 304 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 304 insertions(+)
 create mode 100644 lcd.c

(limited to 'lcd.c')

diff --git a/lcd.c b/lcd.c
new file mode 100644
index 0000000..79b39a9
--- /dev/null
+++ b/lcd.c
@@ -0,0 +1,304 @@
+#include "i2c.h"
+#include "lcd.h"
+#include <glib.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define LCD_ENABLE	0x03	/* the 4x40 LCDs have two enable lines - 0x03 enables both at the same time */
+#define LCD_DATA_RAM	128		/* display RAM, in the LCD ICs */
+#define LCD_CG_RAM	64		/* custom character RAM, in the LCD ICs */
+
+#define LCD_chars_total 160
+#define LCD_cols    	40
+#define LCD_rows    	4		/* 4x40 LCD */
+
+char LCD_Data[LCD_rows][LCD_cols];	/* shadow copy of LCD display in local RAM, to minimize slow I2C writes */
+
+/*** EndHeader */
+
+
+static void break_up_string (char *in_string, int N, char *str1, char *str2, char *str3)
+{
+
+#define SUBSTRING_CNT 3
+
+	int input_length;
+	int j, k, copypos;
+	int n;
+
+	char *copy_input;
+	char *p;
+
+	j=k=copypos=0;
+	input_length=strlen(in_string);
+	copy_input = g_strdup(in_string);
+
+	for (j=0; j<SUBSTRING_CNT; j++) {
+
+		char * interm_str= (char *)malloc((N+1)*sizeof(char));
+		memset(interm_str,0, (N+1)*sizeof(char));
+		for (k=0; k<N; k++) {
+			copypos++; // next symbol
+			if (copypos>input_length) {
+				break;
+			}
+			if ((*(copy_input+k)==' ')&&(copypos<input_length)) { // space found
+				//find next space
+				p=strchr(copy_input+k+1,' ');
+				if (p!=NULL) {
+					// next space is beyond N char limit for one line
+					if((p-copy_input)/sizeof(char)>=N) {
+						break;
+					}
+				} else {
+					// No more spaces. Does the last chunk of text fit?
+					if (strlen(copy_input+k+1)>N-k) {
+						break;
+					}
+				}
+			}
+			// valid character, copy to output string
+			*(interm_str+k)=*(copy_input+k);
+
+		}
+		// remove processed part from the input
+		if (copypos<=input_length) {
+			strcpy(copy_input, in_string+copypos);
+		}
+		n = strlen(interm_str);
+		for (k=n-1; k=0; k--) { //trim   space
+			if (*(interm_str+k)==' ') {
+				*(interm_str+k)=0;
+			} else {
+				break;
+			}
+		}
+		switch (j) {
+		case 0:
+			strcpy(str1,interm_str);
+			break;
+		case 1:
+			strcpy(str2,interm_str);
+			break;
+		case 2:
+			strcpy(str3,interm_str);
+			break;
+		}
+		free(interm_str);
+
+	}
+
+	g_free(copy_input);
+}
+
+
+
+
+void LCD_clear()
+{
+	char i;
+	char j;
+
+	I2C_Write(PCF8574A+LCD_Port, 0x00 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x00);
+	I2C_Write(PCF8574A+LCD_Port, 0x10 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x10);
+
+	/* wait 1.64ms */
+	g_usleep(1640);
+
+	for (i=0; i<4; ++i)
+		for (j=0; j<40; ++j) {
+			LCD_Data[i][j]=0;
+		}
+
+	return;
+}
+
+
+static void LCD_RAM_write(int RAM_start,int row, int col, char *LCD_string)
+{
+	/* rows: 0-3, cols: 0-39 */
+
+#define data_level 0x04
+
+	int i;
+	int cur_row, cur_col;
+	int String_length;
+	char char_out, enable_one_lcd;
+	int ram_location;
+	char last_op_a_write;
+
+	String_length=strlen(LCD_string);
+	enable_one_lcd=0x02;
+
+	last_op_a_write=0;
+	cur_row=row;
+	cur_col=col;
+
+	if (cur_row<2) {
+		enable_one_lcd=0x02;
+	} else {
+		enable_one_lcd=0x01;
+	}
+
+	/* write out the string */
+	for (i=0; i<String_length; ++i) {
+		if (cur_row<2) {
+			enable_one_lcd=0x02;
+		} else {
+			enable_one_lcd=0x01;
+		}
+
+		if (LCD_string[i]!=LCD_Data[cur_row][cur_col]) {
+			if (!last_op_a_write) {
+				/* move to new position */
+				ram_location = (cur_row & 1) * 64 + cur_col + RAM_start;
+				char_out=ram_location & 0xf0;
+				I2C_Write(PCF8574A+LCD_Port, char_out | enable_one_lcd);
+				I2C_Write(PCF8574A+LCD_Port, char_out);
+				char_out=ram_location << 4;
+				I2C_Write(PCF8574A+LCD_Port, char_out | enable_one_lcd);
+				I2C_Write(PCF8574A+LCD_Port, char_out);
+			}
+			LCD_Data[cur_row][cur_col]=LCD_string[i];
+			char_out=LCD_string[i] & 0xf0;
+			I2C_Write(PCF8574A+LCD_Port, char_out | enable_one_lcd | data_level);
+			I2C_Write(PCF8574A+LCD_Port, char_out | data_level);
+			char_out=LCD_string[i] << 4;
+			I2C_Write(PCF8574A+LCD_Port, char_out | enable_one_lcd | data_level);
+			I2C_Write(PCF8574A+LCD_Port, char_out | data_level);
+			last_op_a_write=1;
+		} else {
+			last_op_a_write=0;
+		}
+
+		++cur_col;
+		if (cur_col==40) {
+			cur_col=0;
+			++cur_row;
+		}
+	}
+	return;
+}
+
+
+void LCD_write(int row, int col, char *LCD_string)
+{
+	LCD_RAM_write(LCD_DATA_RAM, row, col, LCD_string);
+	return;
+}
+
+
+static void LCD_make_custom_chars()
+{
+	/* define custom LCD characters 2 and 3 (up arrow and down arrow).*/
+	/* The up arrow is stored in one LCD controller (for rows 0 and 1) */
+	/* The down arrow is stored in the other LCD controller (for rows 2 and 3) */
+	LCD_RAM_write(LCD_CG_RAM,0,16,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,0,17,"\xe");
+	LCD_RAM_write(LCD_CG_RAM,0,18,"\x15");
+	LCD_RAM_write(LCD_CG_RAM,0,19,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,0,20,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,0,21,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,0,22,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,0,23,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,2,24,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,2,25,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,2,26,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,2,27,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,2,28,"\x4");
+	LCD_RAM_write(LCD_CG_RAM,2,29,"\x15");
+	LCD_RAM_write(LCD_CG_RAM,2,30,"\xe");
+	LCD_RAM_write(LCD_CG_RAM,2,31,"\x4");
+// prove that it works - debug only
+//	LCD_RAM_write(LCD_DATA_RAM,0,39,"\x2");
+//	LCD_RAM_write(LCD_DATA_RAM,3,39,"\x3");
+
+	return;
+}
+
+
+void LCD_initialize(void)
+{
+	/* Wait 15ms */
+	g_usleep(15000);
+
+	I2C_Write(PCF8574A+LCD_Port, 0x30 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x30);
+
+	/* wait 4.1ms */
+	g_usleep(4100);
+
+	I2C_Write(PCF8574A+LCD_Port, 0x30 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x30);
+
+	/* wait 100us */
+	g_usleep(100);
+
+	I2C_Write(PCF8574A+LCD_Port, 0x30 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x30);
+
+	/* wait 4.1ms */
+	g_usleep(4100);
+
+	I2C_Write(PCF8574A+LCD_Port, 0x20 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x20);
+
+	/*wait 40us */
+	g_usleep(40);
+
+	I2C_Write(PCF8574A+LCD_Port, 0x20 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x20);
+	I2C_Write(PCF8574A+LCD_Port, 0x80 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x80);
+
+	/* wait 40us */
+        g_usleep(40);
+
+	LCD_clear();
+
+	I2C_Write(PCF8574A+LCD_Port, 0x00 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x00);
+	I2C_Write(PCF8574A+LCD_Port, 0x60 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x60);
+
+	/* wait 40us */
+        g_usleep(40);
+
+	I2C_Write(PCF8574A+LCD_Port, 0x00 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0x00);
+	I2C_Write(PCF8574A+LCD_Port, 0xc0 | LCD_ENABLE);
+	I2C_Write(PCF8574A+LCD_Port, 0xc0);
+
+	LCD_make_custom_chars();
+
+	return;
+}
+
+
+void LCD_display_error_message(char *response)
+{
+	char row0[LCD_cols+1];
+	char row1[LCD_cols+1];
+	char row2[LCD_cols+1];
+
+	memset(row0,0,LCD_cols+1);
+	memset(row1,0,LCD_cols+1);
+	memset(row2,0,LCD_cols+1);
+
+//	Error_Screen=1;  //FIXME
+
+	break_up_string (response, LCD_cols, row0, row1, row2);
+
+	LCD_clear();
+	LCD_write(0,0,row0);
+	LCD_write(1,0,row1);
+	LCD_write(2,0,row2);
+	LCD_write(3,0,Press_Change_Message);
+
+	return;
+}
+
+
+
-- 
cgit