1602LCD_char_display.c

@@ -66,7 +66,6 @@
  * DB4~DB7: high order three-state data lines.
  */
 
-
 //#############################
 //MACROS
 //#############################
@@ -84,7 +83,7 @@
 
 
 void init_lcd(void);
-void cmd_lcd(uint8_t cmd);
+//void cmd_lcd(uint8_t cmd);
 void cmd_nibble_lcd(uint8_t cmd);
 void clear_lcd(void);                                                                                               
 static void led_blink(void);
@@ -102,20 +101,12 @@ void write_lcd_address(uint8_t addr);
 int main() {
     //SETUP HERE.
     _delay_ms(500);
-   
-    //setup for single line mode.
-    //cmd_lcd(0x20);
-    //_delay_ms(1000);
-    //cmd_lcd(0x28);
-
     while(1) {
         led_blink();
         _delay_ms(1000);
-        cmd_lcd(0x20);
+        set_lcd_one_line();
         _delay_ms(1000);
-        cmd_lcd(0x28);
+        set_lcd_two_line();
-        _delay_ms(2);
-
     }
     
     return 0;
@@ -151,28 +142,34 @@ void init_lcd(void) {
  * Description: Sets the LCD into 4bit two line display mode.
  */
 void set_lcd_two_line(void) {
-    cmd_lcd(0x28);
+    cmd_nibble_lcd(0x20);
+    cmd_nibble_lcd(0x80);
 }
 
 void set_lcd_one_line(void) {
-    cmd_lcd(0x20);
+    cmd_nibble_lcd(0x20);
+    cmd_nibble_lcd(0x00);   
 }
 
 void clear_lcd(void) {
-    cmd_lcd(0x01);
+    cmd_nibble_lcd(0x00);
+    cmd_nibble_lcd(0x10);
 }
 
 void return_home_lcd(void) {
-    cmd_lcd(0x02);
+    cmd_nibble_lcd(0x00);
+    cmd_nibble_lcd(0x20);
 }
 
 void turn_off_lcd(void) {
-    cmd_lcd(0x08);
+    cmd_nibble_lcd(0x00);
+    cmd_nibble_lcd(0x80);
 }
 
 
 void turn_on_lcd(void) {
-    cmd_lcd(0x08);
+    cmd_nibble_lcd(0x00);
+    cmd_nibble_lcd(0x80);
 }
 
 
@@ -191,31 +188,9 @@ void write_lcd_address(uint8_t addr) {
 }
 
 
-/*
+//A version that doesn't require multiple calls.
- * Input: uint8_t, a 8bit command code.
- * Output: none
- * Description: Takes a 8bit command code and sends it as two 4bit nibbles
- * to the 1602LCD. The timing of delays is very important to match the 
- * datasheets timing diagrams.
- */
 void cmd_lcd(uint8_t cmd) {
-    DDRD = 0xff;
+;
-    PORTD &=0x0f;
-
-    //Send first nibble
-    setbit(PORTD, ENA_PIN);
-    PORTD |= (cmd & 0xf0);
-    _delay_ms(1);
-    clearbit(PORTD, ENA_PIN);
-    _delay_ms(2);
-
-    //Send the second nibble and shift cmd by four.
-    PORTD &= 0x0f;
-    setbit(PORTD, ENA_PIN);
-    PORTD |= (cmd<<4);
-    _delay_ms(1);
-    clearbit(PORTD, ENA_PIN);
-    _delay_ms(2);
 }
 
 void cmd_nibble_lcd(uint8_t cmd) {