What is wrong with my code ??

[afesheir]

hi everybody ..
I hope I find my needs in this great board ..
Now I am trying to initialize MMC SanDisk 1GB using my own code (without using mikroC library) with PIC16F877A ..

When the card is initialized, I want my GLCD to display the word "Ready", otherwise I want to display "Initializing ..." ..

before anything, I want to display "WELCOME" ..

the GLCD is functioning properly alone, but with my code, the glcd displays nothing ..

here is my code:

Code:


//module connection

char GLCD_DataPort at PORTD;
sbit GLCD_CS1 at RB0_bit;
sbit GLCD_CS2 at RB1_bit;
sbit GLCD_RS at RB2_bit;
sbit GLCD_RW at RB3_bit;
sbit GLCD_EN at RB4_bit;
sbit GLCD_RST at RB5_bit;
sbit GLCD_CS1_Direction at TRISB0_bit;
sbit GLCD_CS2_Direction at TRISB1_bit;
sbit GLCD_RS_Direction at TRISB2_bit;
sbit GLCD_RW_Direction at TRISB3_bit;
sbit GLCD_EN_Direction at TRISB4_bit;
sbit GLCD_RST_Direction at TRISB5_bit;


// Software SPI module connections
sbit SoftSpi_SDI at RC4_bit;
sbit SoftSpi_SDO at RC5_bit;
sbit SoftSpi_CLK at RC3_bit;

sbit SoftSpi_SDI_Direction at TRISC4_bit;
sbit SoftSpi_SDO_Direction at TRISC5_bit;
sbit SoftSpi_CLK_Direction at TRISC3_bit;
// End Software SPI module connections


void sendCommand(int cmdIndex); //function prototype

void main() {
unsigned char Response;


Soft_SPI_Init(); // Init Soft_SPI
Glcd_Init(); //Init. GLCD
// Glcd_Set_Font(font5x7 , 5, 7, 32);// Change font
Glcd_Fill(0x00); //Clear GLCD
Glcd_Write_Text("WELCOME",0,0,1);


TRISC.B1=0; //Make RC2 output pin (CS or SS Pin)
PORTC.B1=0; //Hold CC=0
delay_ms(4); //Delay about 75 clock pulses at 20KHz

sendCommand(0x00); //CMD0 for S/W reset
Init:sendCommand(0x37); //CMD55 to tell that the next command is Application Specific
sendCommand(0x29); //ACMD41 to Initialize the SD Card
Response= Soft_Spi_Read(0x00);

if (Response==0x00)
{
Glcd_Fill(0x00); //Clear GLCD
Glcd_Write_Text("Ready !!",20,4,1);

}
else
{
Glcd_Fill(0x00);
Glcd_Write_Text("Initializing ...",20,4,1);
goto Init;
}

}

void sendCommand(int cmdIndex)
{
Soft_Spi_Write(0x40+cmdIndex); //Send command of index cmdIndex
Soft_Spi_Write(0x00); //Send 4
Soft_Spi_Write(0x00); //Clear Bytes
Soft_Spi_Write(0x00); //As
Soft_Spi_Write(0x00); //Argument
Soft_Spi_Write(0x95); //CRC = 0x95 for CMD0 and not important for SPI mode
}


also I am asking about the red number, this function is to read data from spi bus, why do we need to assign data to send ..?

Great thanks to everybody ..

 

[jack0987]

Do not know a thing about microcontrollers, but if you place a breakpoint after your line of code

Glcd_Write_Text("WELCOME",0,0,1);

Do you see the word welcome?

 

[afesheir]

thx jack
i did comment the entire code after

Glcd_Write_Text("WELCOME",0,0,1);

and the problem still present ..

 

[upand_at_them]

Why are you trying to debug too many steps at once? You've got 3 things happening before it outputs "welcome". Does your code reach and execute each one?

 

[afesheir]

yes upand ..
now the GLCD works fine and display texts without problems .. but I am seeking the SD initialization now .. I got "Initializing" on the screen all the time and the SD never gets ready .. why ?

 

[upand_at_them]

Sorry for misunderstanding your problem.

This isn't the same programming language, but it's a sample of the code I've used for using an SD card with a PIC. It's using the SPI mode, not MMC. It's been so long since I've used this that I'm not much help in explaining it, only that it does work.

function MMC_Reset return bit is
	
	CS = high
	
	for 10 loop
		SPI(0xFF)
	end loop
		
	CS = low
	
	MMC_Command(0x40, 0, 0, 0, 0, 0x95)
	
	if ! MMC_Response(0x01) Then
		return false
	end if
	
	for 255 loop
		MMC_Command(0x41, 0, 0, 0, 0, 0xFF)
		if MMC_Response(0x00) Then
			-- exit with success
			CS = high
			SPI(0xFF)
			return true
		end if
	end loop
	
	return false
	
end function

 

[Oznog]

nevermind, delete

 

[Mehmood Ahmed]

what i understand by reading mikroC help...you should provide a variable to Soft_SPI_Read() function which will store the data which read from spi bus instead of a constant....that's how it should work..