[SOLVED] megawin 8051 mcu interfacing with I2C 16x2 LCD

[funguamongu]

Hello
I recently got my hands on Megawin MG82F6D17 mcus. They are cheaper than PIC and ATMEGA mcus in my county. I have been trying to use the sample code provided by the support site of the manufacturer but I cannot figure out how to get it to work with the LCD.

u8 TWI0_WriteBuf(u8 DevAddr,u16 RegStartAddr,u8 *pBuf,u8 Len)
{
    u8 i;
    u8 Flag;
    Flag=1;

    SICON |=STA;                        // Send START
    TWI0OvTime=5;
    SICON &=~SI;           
    while((SICON&SI)!=SI){if(TWI0OvTime==0) goto TWI0_WRITE_ERR;}        // wait completed, if time overflow,then return fail.
    SICON &=~STA;

    SICON=SICON|(AA);      

    Flag++;
    SIDAT = DevAddr&0xFE;                // send Slave Device address 
    TWI0OvTime=5;
    SICON &=~SI;           
    while((SICON&SI)!=SI){if(TWI0OvTime==0) goto TWI0_WRITE_ERR;}        // wait completed, if time overflow,then return fail.

    Flag++;
    SIDAT = HIBYTE(RegStartAddr);        // send Slave Data address high
    TWI0OvTime=5;
    SICON &=~SI;           
    while((SICON&SI)!=SI){if(TWI0OvTime==0) goto TWI0_WRITE_ERR;}        // wait completed, if time overflow,then return fail.

    Flag++;
    SIDAT = LOBYTE(RegStartAddr);        // send Slave Data address low
    TWI0OvTime=5;
    SICON &=~SI;           
    while((SICON&SI)!=SI){if(TWI0OvTime==0) goto TWI0_WRITE_ERR;}        // wait completed, if time overflow,then return fail.


    Flag++;
    i=0;
    while(i<Len)
    {
        if(i==(Len-1))
        {
            SICON=SICON&(~AA);      
        }
        else
        {
            SICON=SICON|(AA);      
        }
        SIDAT=pBuf[i];            // send  Data
        TWI0OvTime=5;
        SICON &=~SI;           
        while((SICON&SI)!=SI){if(TWI0OvTime==0) goto TWI0_WRITE_ERR;}        // wait completed, if time overflow,then return fail.
        i++;
    }
                   
    Flag++;
    SICON |= STO;                // Send STOP
    TWI0OvTime=5;
    SICON &=~SI;           
    while((SICON&STO)==STO){if(TWI0OvTime==0) goto TWI0_WRITE_ERR;}        // wait completed, if time overflow,then return fail.
    SICON &=~STO;

    SICON = SICON &(~SI);       

    return 0;
   
TWI0_WRITE_ERR:
    return Flag;
}

This was the sample code in the package, I need help getting it to work

Many thanks

--- Updated Apr 19, 2024 ---

Full sample code for I2C provided by Megawin

 

[doraemon]

Hello!

A good way to start would be to clearly explain what you did.
Apparently you included a code snippet that you didn't write yourself.
But what did you do with it?
Is it a hardware you have developed? -> Are you sure the wiring is correct?
Or do you use the dev board indicated in the source code (MG82F6D17 SSOP20_V10 EV Board)?
By the way, does it compile without errors?
Some more info may help.

Dora.

 

[andre_luis]

while ( (SICON&SI)!=SI){if(TWI0OvTime==0) goto TWI0_WRITE_ERR; }
This was the sample code in the package, I need help getting it to work

If I were you, I wouldn't spend a second debugging a code like this, which in addition to being poorly written ( goto's should be avoided as much as possible ), it is also not quite intelligible.

 

[funguamongu]

Yes it did compile without errors

This is my first project with an 8051 mcu. The I2C code provided by the manufacturer looked too complex so I have moved on to using 4 bit mode without the i2c module. Now I have new problems. No matter what I do, the first line is filled with blocks as if its on full contrast.
Here is the code I wrote (partially)

#include ".\include\REG_MG82F6D17.H"
#include ".\include\Type.h"
#include ".\include\API_Macro_MG82F6D17.H"
#include ".\include\API_Uart_BRGRL_MG82F6D17.H"
#include <Intrins.h>
#define LCD_Port P1        /* P1 port as data port */
#define rs P22            /* Register select pin */
#define en P24            /* Enable pin */
#define MCU_SYSCLK        12000000
#define MCU_CPUCLK        (MCU_SYSCLK)


void DelayXus(u8 xUs)
{
    while(xUs!=0)
    {
#if (MCU_CPUCLK>=11059200)
        _nop_();
#endif
#if (MCU_CPUCLK>=14745600)
        _nop_();
        _nop_();
        _nop_();
        _nop_();
#endif
#if (MCU_CPUCLK>=16000000)
        _nop_();
#endif

#if (MCU_CPUCLK>=22118400)
        _nop_();
        _nop_();
        _nop_();
        _nop_();
        _nop_();
        _nop_();
#endif
#if (MCU_CPUCLK>=24000000)
        _nop_();
        _nop_();
#endif        
#if (MCU_CPUCLK>=29491200)
        _nop_();
        _nop_();
        _nop_();
        _nop_();
        _nop_();
        _nop_();
#endif
#if (MCU_CPUCLK>=32000000)
        _nop_();
        _nop_();
#endif

        xUs--;
    }
}


void DelayXms(u16 xMs)
{
    while(xMs!=0)
    {
        CLRWDT();
        DelayXus(200);
        DelayXus(200);
        DelayXus(200);
        DelayXus(200);
        DelayXus(200);
        xMs--;
        
    }
}






void LCD_Command (char cmnd)    /* LCD16x2 command funtion */
{
    LCD_Port=0;
    rs=0;

    LCD_Port =((cmnd >>4 )& 0x0F);
                
    en=1; 
    DelayXus(1);
    en=0;
  
    rs=0;

    LCD_Port = (cmnd & 0x0F);        
    en=1; 
    DelayXus(1);
    en=0;
    LCD_Port=0;



}

void LCD_Char (char char_data)  /* LCD data write function */
{
    LCD_Port=0;
    rs=1;

    LCD_Port = ((char_data >>4 ) & 0x0F);
    
    en=1;
    DelayXus(1);
    en=0;
    
    rs=1;

    LCD_Port =(char_data & 0x0F);
    
    en=1;
    DelayXus(1);
    en=0;

  LCD_Port=0;

}



void LCD_Init (void)        /* LCD Initialize function */
{

    LCD_Command(0x28);
    LCD_Command(0x06);
    LCD_Command(0x0F);
    LCD_Command(0x10);
    LCD_Command(0x01);
    
}

void main()
{ 
  PORT_SetP1PushPull(BIT0|BIT1|BIT5|BIT6|BIT7);
  PORT_SetP2PushPull(BIT2|BIT4);
    LCD_Init();    
    DelayXms(10);
    while(1);
}

This is the description of port 1. In all the tutorials ive found via google, the mcus they use have 8 pins on the port they use for lcd data communication, and the lcd is wired to the last 4 pins. Mine only has 5 and im using 1,5,6,7. Could this be an issue?