lcm.c

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/*********************************************************
* Function: lcm driver
* 4 bit lcm control is used. 
* timer 1 is used for lcm
*
* File: lcm.c
* Author: Book Chen
* Date 2009.07.06
***********************************************************
*/
#include "includes.h"

#define LcmIdleState    0
#define LcmUpdateState  1

#define LcmHigh4bitSubstate 0
#define LcmLow4bitSubstate  1

#define LcmData0 RJ4
#define LcmData1 RJ5
#define LcmData2 RJ6
#define LcmData3 RJ7

#define LcmBackLightEn RB4
#define LcmRs RB1
#define LcmRw RB2
#define LcmEn RB3

//INT8U MenuLcmInitialCommand0[]={0x38,0x08,0x01,0x06,0x0c,0x38,0x80,0x00};
INT8U LcmClean[]={0x01,0x00};
INT8U LcmInitialCommand0[]={0x33,0x32,0x08,0x01,0x06,0x0c,0x00};
INT8U Lcm1stLineStart[]={0x80,0x00};
INT8U Lcm2ndLineStart[]={0xc0,0x00};

INT8U LcmBuffer[17];
LCM_CONTROL LcmCtrl;
/*****************
* LcmInit:
* Initialize Lcm variables.
******************
*/
void LcmInit(void){
    TRISJ=0;
    TRISB=0;

    LcmData0=1;
    LcmData1=1;
    LcmData2=1;
    LcmData3=1;
    LcmBackLightEn=1;
    LcmRs=1;
    LcmRw=1;
    LcmEn=1;

    LcmCtrl.HasData=FALSE;
    LcmCtrl.Length=0;
    LcmCtrl.Timer=200;
    LcmCtrl.State=LcmIdleState;
    LcmCtrl.SubState=LcmHigh4bitSubstate;
}
/*****************
* LcmStateGet:
* Get lcm current operation state.
******************
*/
INT8U LcmStateGet(void){
    return LcmCtrl.State;
}
/*****************
* LcmUpdate:
* Write commands or data to lcm
******************
*/
ERROR LcmUpdate(INT8U *pLcmData,INT8U DataType){
    INT8U Length;
    const INT8U *pData;     

    if(LcmCtrl.State!=LcmIdleState){
         DebugStringPrint("\r\n Lcm0 error");
         return IS_ERROR;
    }
    pData=pLcmData;
    for(Length=0;Length<50;){
        if(*pData!=0){
            Length++;
            pData++;
        }
        else break;
    }
    if(Length>=50){ // length too long
         DebugStringPrint("\r\n Lcm1 error");
         return IS_ERROR;
    } 
    LcmCtrl.DataType=DataType;
    LcmCtrl.Length=Length;
    LcmCtrl.pData=pLcmData;    
    LcmCtrl.SubState=LcmHigh4bitSubstate;
    LcmCtrl.State=LcmUpdateState;
    TMR1ON=0;                // stop timer 1
    LcmCtrl.HasData=TRUE;
    TMR1ON=1;                // start timer 1
    while(LcmStateGet()!=0) LcmSvc();
    return NO_ERROR;
}

void LcmSvc(void){
    if(LcmCtrl.HasData==FALSE) return; // prevent previous command not finished
    if(LcmCtrl.Timer!=0) return;       // prevent previous command not finished
    LcmCtrl.Timer=10;
    if(LcmCtrl.DataType==LCM_COMMAND){
        if(LcmCtrl.SubState==LcmHigh4bitSubstate){
            LcmCommandWrite((*LcmCtrl.pData&0xf0)>>4);
            LcmCtrl.SubState=LcmLow4bitSubstate;
        }
        else{
            LcmCommandWrite(*LcmCtrl.pData&0x0f);
            LcmCtrl.Length--;
            LcmCtrl.pData++;
            LcmCtrl.SubState=LcmHigh4bitSubstate;
        }
    }
    else{
        if(LcmCtrl.SubState==LcmHigh4bitSubstate){
            LcmDramWrite((*LcmCtrl.pData&0xf0)>>4);
            LcmCtrl.SubState=LcmLow4bitSubstate;
        }
        else{
            LcmDramWrite(*LcmCtrl.pData&0x0f);
            LcmCtrl.Length--;
            LcmCtrl.pData++;
            LcmCtrl.SubState=LcmHigh4bitSubstate;
        }
    }
    if(LcmCtrl.Length==0) LcmCtrl.HasData=FALSE; 
}

void LcmCommandWrite(INT8U Command){
    LcmRw=0;                // Read 1/ write 0
    LcmRw=0; 
    LcmRw=0; 
    LcmRs=0;                // Select command register 
    LcmRs=0;
    LcmRs=0;
    if(Command&0x01) LcmData0=1;
    else LcmData0=0;
    if(Command&0x02) LcmData1=1;
    else LcmData1=0;
    if(Command&0x04) LcmData2=1;
    else LcmData2=0;
    if(Command&0x08) LcmData3=1;
    else LcmData3=0;
    LcmEn=1;
    LcmEn=1;
    LcmEn=1;
    LcmEn=0;
    LcmEn=0;
    LcmEn=0;
}

void LcmDramWrite(INT8U Data){
    LcmRw=0;                // Read 1/ write 0
    LcmRw=0; 
    LcmRw=0; 
    LcmRs=1;                // lcm dram
    LcmRs=1;
    LcmRs=1;
    if(Data&0x01) LcmData0=1;
    else LcmData0=0;
    if(Data&0x02) LcmData1=1;
    else LcmData1=0;
    if(Data&0x04) LcmData2=1;
    else LcmData2=0;
    if(Data&0x08) LcmData3=1;
    else LcmData3=0;
    LcmEn=1;
    LcmEn=1;
    LcmEn=1;
    LcmEn=0;
    LcmEn=0;
    LcmEn=0;
}

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