Rob Toulson / Mbed 2 deprecated PE_08-01to04_ModularLCD

by Rob Toulson and Tim Wilmshurst from textbook "Fast and Effective Embedded Systems Design: Applying the ARM mbed"

Dependencies:   mbed

LCD.cpp@0:519ae7e3077e, 2013-05-24 (annotated)

Committer:
robt
Date:
Fri May 24 21:33:46 2013 +0000
Revision:
0:519ae7e3077e
by Rob Toulson and Tim Wilmshurst from textbook "Fast and Effective Embedded Systems Design: Applying the ARM mbed"

Who changed what in which revision?

UserRevisionLine numberNew contents of line
robt 0:519ae7e3077e 1 #include "LCD.h"
robt 0:519ae7e3077e 2
robt 0:519ae7e3077e 3 DigitalOut RS(p19); // RS
robt 0:519ae7e3077e 4 DigitalOut RW(p19); // RW
robt 0:519ae7e3077e 5 DigitalOut E(p20); // Enable
robt 0:519ae7e3077e 6 BusOut data(p21, p22, p23, p24);// DB4-DB7
robt 0:519ae7e3077e 7
robt 0:519ae7e3077e 8 /****initialise LCD function ****/
robt 0:519ae7e3077e 9 void LCD_init(void){
robt 0:519ae7e3077e 10
robt 0:519ae7e3077e 11 wait(0.02);
robt 0:519ae7e3077e 12 RS=0; // set all low to write control/instruction data
robt 0:519ae7e3077e 13 // RW=0;
robt 0:519ae7e3077e 14 E=0;
robt 0:519ae7e3077e 15
robt 0:519ae7e3077e 16 // Function set
robt 0:519ae7e3077e 17 data=0x2; // = 4 bit mode
robt 0:519ae7e3077e 18 toggle_enable();
robt 0:519ae7e3077e 19 data=0x8; // = 2-line mode, 7 dot characters
robt 0:519ae7e3077e 20 toggle_enable();
robt 0:519ae7e3077e 21
robt 0:519ae7e3077e 22 // Display Mode
robt 0:519ae7e3077e 23 data=0x0; //
robt 0:519ae7e3077e 24 toggle_enable();
robt 0:519ae7e3077e 25 data=0xF; // display on, cursor on, blink on
robt 0:519ae7e3077e 26 toggle_enable();
robt 0:519ae7e3077e 27
robt 0:519ae7e3077e 28 // Clear display
robt 0:519ae7e3077e 29 data=0x0; //
robt 0:519ae7e3077e 30 toggle_enable();
robt 0:519ae7e3077e 31 data=0x1; // clear
robt 0:519ae7e3077e 32 toggle_enable();
robt 0:519ae7e3077e 33
robt 0:519ae7e3077e 34 }
robt 0:519ae7e3077e 35
robt 0:519ae7e3077e 36
robt 0:519ae7e3077e 37 /**** display ****/
robt 0:519ae7e3077e 38 void display_to_LCD(char value ){
robt 0:519ae7e3077e 39
robt 0:519ae7e3077e 40 RS=1;
robt 0:519ae7e3077e 41 //***** display character *****************
robt 0:519ae7e3077e 42 data=value>>4; // value shifted right 4 = upper
robt 0:519ae7e3077e 43 toggle_enable();
robt 0:519ae7e3077e 44 data=value&0x0F; // value bitmask with 0x0F = lower
robt 0:519ae7e3077e 45 toggle_enable();
robt 0:519ae7e3077e 46 }
robt 0:519ae7e3077e 47
robt 0:519ae7e3077e 48
robt 0:519ae7e3077e 49 /**** toggle enable function ****/
robt 0:519ae7e3077e 50 void toggle_enable(void){
robt 0:519ae7e3077e 51 E=1;
robt 0:519ae7e3077e 52 wait(0.001);
robt 0:519ae7e3077e 53 E=0;
robt 0:519ae7e3077e 54 wait(0.001);
robt 0:519ae7e3077e 55 }
robt 0:519ae7e3077e 56
robt 0:519ae7e3077e 57 /**** set location function ****/
robt 0:519ae7e3077e 58 void set_location(char location){
robt 0:519ae7e3077e 59 RS=0;
robt 0:519ae7e3077e 60 data=(location|0x80)>>4; // upper nibble
robt 0:519ae7e3077e 61 toggle_enable();
robt 0:519ae7e3077e 62 data=location&0x0F; // lower nibble
robt 0:519ae7e3077e 63 toggle_enable();
robt 0:519ae7e3077e 64 }