Diff: main.cpp

Revision:

0:639529b48adf

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Oct 15 19:14:01 2010 +0000
@@ -0,0 +1,97 @@
+
+/* Lcd_Custom_Char
+
+Author: Lluis Nadal.
+Date: 15th October 2010.
+
+Up to 8 characters can be programmed in CGRAM, but because CGRAM is a RAM, characters are lost
+on power off and must be reloaded on power on.
+Assuming 2x16 LCD with HD44780 Hitachi controller compatible.
+
+*/
+
+#include "mbed.h"
+#include "TextLCD.h"
+
+
+// Defines LCD connections.
+TextLCD lcd(p24, p26, p27, p28, p29, p30); // rs, e, d4, d5, d6, d7
+
+// Defines 8 custom characters.
+char custom_char[8][8] = {
+    {0x07,0x08,0x1F,0x08,0x1F,0x08,0x07,0x00}, // Euro sign.
+    {0x00,0x0E,0x11,0x11,0x11,0x0A,0x1B,0x00}, // Ohm sign.
+    {0x00,0x00,0x00,0x12,0x12,0x12,0x1C,0x10}, // Micro sign.
+    {0x00,0x00,0x1F,0x0A,0x0A,0x0A,0x0A,0x00}, // Pi sign.
+    {0x0C,0x12,0x12,0x0C,0x00,0x00,0x00,0x00}, // Degree sign.
+    {0x0E,0x04,0x0E,0x15,0x015,0x0E,0x04,0x0E},// Phi sign.
+    {0x04,0x0E,0x15,0x04,0x04,0x04,0x04,0x04}, // Arrow up.
+    {0x04,0x04,0x04,0x04,0x04,0x15,0x0E,0x04}  // Arrow down.
+};
+
+
+// Defines LCD bus to write data.
+BusOut Lcd_pins(p27, p28, p29, p30); // d4, d5, d6, d7
+
+DigitalOut rs_pin(p24); // LCD pin rs (register select.)
+DigitalOut e_pin(p26);  // LCD pin e (enable).
+
+
+// Because we use 4 bit LCD, data must be sent in two steps.
+void writePort(int value) {
+
+    Lcd_pins = value >> 4;  // Shifts 4 bit right.
+    wait(0.000040f); // Wait 40us.
+    e_pin = 0;
+    wait(0.000040f);
+    e_pin = 1;
+    Lcd_pins = value;
+    wait(0.000040f);
+    e_pin = 0;
+    wait(0.000040f);
+    e_pin = 1;
+}
+
+
+
+int main() {
+
+
+    lcd.cls();
+    lcd.printf("Loading...");
+    wait(2);
+
+
+    for (int j=0; j<8; j++) {
+
+        rs_pin = 0; // We send a command.
+
+        /* 0X40 is the initial CGRAM address. Because each character needs a total amount of 8 memory 
+        locations, we increment addres in 8 units after each character.
+        */
+        writePort(0x40+8*j);
+
+
+// Writes data.
+        rs_pin = 1; // We send data.
+
+
+        for (int i=0; i<8; i++) {
+            writePort(custom_char[j][i]);
+        }
+    }
+
+
+
+    lcd.cls();
+    wait(0.010);
+
+    lcd.printf("Custom character");
+    lcd.locate(0,1);
+
+// Prints loaded custom characters. ASCII codes 0 to 7.
+    for (int j=0; j<8; j++) {
+        lcd.putc(j);
+    }
+
+}
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