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| Roomba Dashboard |
DIP switch set at: 1-off 2-on 3-off 4-on 5-off 6-on 
| Pin # | Name | Function |
| 1 | Vss | Ground ( 0v) |
| 2 | Vdd | +5 volts |
| 3 | Reset | When this pin is low it resets the LCD. You can either tie this pin to a pin on your microcontroller so you can reset the LCD before initializtion, or just tie it high. I had a couple of times where I couldn't init the LCD without first resetting it, so I'd recommend putting it under micro control, or some other powerup controller. The reset low time should be at least 10ms. The time after reset before you start commanding the LCD should also be at least 10 ms. |
| 4 | RS | Register Select. This pin determines whether the data you're about to write is a command or a data byte. Commands do interesting stuff to the LCD, like set the number of lines or contrast. Data is what actually gets put on the screen, or in the custom character registers. High means Data, Low means command |
| 5 | Read/Write | Set this pin high to read from the display. Set this pin low to write to it. If you don't need to update the display super fast you can save an I/O line by just tying it to ground. Wait at least a millisecond between each command and data, though, since you can't query the busy status without read capability. |
| 6 | E | Enable. This line works to clock in data and commands. See the protocol section below. |
| 7 | DB0 | Least Significant Data Bit |
| 8 | DB1 | |
| 9 | DB2 | |
| 10 | DB3 | |
| 11 | DB4 | |
| 12 | DB5 | |
| 13 | DB6 | |
| 14 | DB7 |
lcd_wintek_wdc2401p.h:
#define E_LO PORTA &= ~0x80; //RA7
#define E_HI PORTA |=0x80
#define RS_HI PORTA |=0x40 //RA6
#define RS_LO PORTA &= ~0x40
#define RESET_LO PORTA &= ~0x04
#define RESET_HI PORTA |= 0x04
#define LCD_DATA PORTB
#define DELAY10MS __delay_ms(10)
#define DELAY1MS __delay_ms(1)
#define DELAY5MS __delay_ms(5)
#define DELAY20MS __delay_ms(20)
#define DELAY90MS __delay_ms(90)
#define DELAY0_5MS __delay_us(500)
#define DELAY5US __delay_us(5)
void LCDInitialize();
void LCDWriteChar(char c);
void LCDClockByte(char c); //Called internally do not use
void LCDClearScreen();
void LCDWriteString(char *s);
void LCDResetChar(); //Return back to first address
lcd_wintek_wdc2401p.c:
#include "lcd_wintek_wdc2401p.h"
void LCDInitialize()
{
DELAY90MS;
RESET_LO;
DELAY20MS;
RESET_HI;
DELAY20MS;
//Initialize Sequence
E_LO;
DELAY5US;
RS_LO;
DELAY1MS;
LCDClockByte(0x1C); //Turn on the lcd driver power
LCDClockByte(0x14); //Turn on the character display
LCDClockByte(0x28); //Set two display lines (The hd66717 considers
//12 characters to be a line. Our 24 character display is
//actually two 12-character lines right next to each other).
LCDClockByte(0x4F); //Set to darkest contrast
LCDClockByte(0xE0); //Set the data address to the first character
DELAY5MS;
}
void LCDClockByte(char c)
{
DELAY1MS;
LCD_DATA = c;
E_HI;
DELAY5US;
E_LO;
}
void LCDWriteChar(char c)
{
RS_HI;
LCDClockByte(c);
}
void LCDResetChar()
{
RS_LO;
LCDClockByte(0x02);
}
void LCDWriteString( char *s)
{
unsigned char c,i,end_flag=0;
DELAY1MS;
LCDResetChar();
DELAY1MS;
for(i=0;i< 24;i++) {
c = (s[i] == 0x00)?'-':s[i];
if(s[i] == 0x00 || end_flag == 1){
c = ' ';
end_flag = 1;
} else {
c = s[i];
}
LCDWriteChar(c);
}
}
void LCDClearScreen()
{
RS_LO;
LCDClockByte(0x01);
}
main.c: (Sample Usage)
#include "lcd_wintek_wdc2401p.h"
main() {
//Make sure you setup the pins on the micro controller for output
// and designate the pins properly in the include file.
char s[]="abcdefghijklmnop";
LCDInitialize();
LCDClearScreen();
LCDWriteString(s);
}
