How To to build an ISP for Atmega 128

You can check out Electronics For You Vol 31 nov 2005 edition

or

First of all ATMEGA 128 supports ISP. One can use the same ISP programmer used for ATMEGA 16/32 to burn a ATMEGA 128. In your target platform just take out the connections for SPI, (MISO, MOSI, SCK, and RESET) and connect those line to your ISP programmer. For schematic and PCB layout mail me : nibir.chakraborty@gmail.com. You can mention the details of the target board like what other things you want in the platform.

code for line following robot in atmega8

Basically a line following robot is the one which follows a particular line and moves along with that line even if its straight or curved or any thing you can look at the following video for a typical example



Now this is the source code for the line following Robot.
this will work for atmega8

int main(void)
{
DDRB|=0x0F;
PORTB=0x0F6;
while(1)
{PORTB|=0x06;
PORTB&=0x0F9;
}
}

with the above code the bot will move only in the straight path now if you want it to move in different directions just change the code in the while loop

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Interfacing Multimedia card with ATMega 128

I am interfacing Multimedia card with ATMega 128 through SPI protocol. For that while reading data from Multimedia Card, I use to send dummy bytes through MOSI and receive data through MISO in SPDR.
hears some routine. Take a Look on them

void SPI_init(void)

{

DDRB |= (1 << SPICS); // 0 set port B SPI chip select to output

DDRB |= (1 << SPICLK); // 1 set port B SPI clock to output

DDRB |= (1 << SPIDO); // 2 set port B SPI data out to output

DDRB &= ~(1 << SPIDI); // 3 set port B SPI data input to input

SPCR = (1 << SPE) | (1 << MSTR); //pg#168(391)

SPICS_ON();

}





char Command(char befF, int AdrH, int AdrL, char CRC )

{ // sends a command to the MMC

SPI(0xFF);

SPI(befF);

SPI((AdrH >> 8));

SPI(AdrH);

SPI((AdrL >> 8));

SPI(AdrL);

SPI(CRC);

SPI(0xFF);

return SPI(0xFF); // return the last received character

}



unsigned char SPI(unsigned char mydata)//transmit through SPI data out
line(MOSI)

{

//unsigned char Rx_SPDR=0xDC, Rx;

SPDR = mydata; //1 Byte data

while(!(SPSR & (1<<SPIF))) // wait for complete transmission

;

//printf("\r\nRx_SPDR = 0x%X", Rx_SPDR);

//Rx=SPDR;

//printf("\r\nRx_SPDR = 0x%X", Rx_SPDR);

return SPDR; //return the received value of SPDR

}





int Read_from_MMC(void) { // send 512 bytes from the MMC via the serial port

int i;

// 512 byte-read-mode

if (Command(0x51,0,512,0xFF) != 0)

{

printf("MMC: read error 1 ");

return 0;

}

// wait for 0xFE - start of any transmission

// ATT: typecast (char)0xFE is a must!

while(SPI(0xFF) != (char)0xFE);



for(i=0; i < 512; i++)

{

while(!(UCSR0A & (1 << UDRE0))); // wait for serial port

/*Here we are transmitting 0xFF through MOSI and then assigning the received
character to USART Data Register*/

UDR0 = SPI(0xFF); // send character

}





// at the end, send 2 dummy bytes

SPI(0xFF); // actually this returns the CRC/checksum byte

SPI(0xFF);

return 1;

}

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Serial Port interfacing with atmega

Here is the code to interface atmega32 and serial port.


.include"m32def.inc"
.org 0000
rjmp main


main: ldi r16,low(ramend)
out SPL,r16
ldi r16,high(ramend)
out SPH,r16

ldi r18,0x00
out UBRRH,r18
ldi r18,0x19 ;setting baud rate of 2400 for 1MHZ
out UBRRL,r18
ldi r19,0x18
out UCSRB,r19 ;enabling RX & TX bits
ldi r19,0x86
out UCSRC,r19 ;setting aychronous mode with 1 stop
;& 1start bit & no parity
again: rcall usart_rx
rcall usart_tx
rjmp again




usart_rx: sbis UCSRA,RXC
rjmp usart_rx
in r17,UDR

ret


usart_tx: sbis UCSRA,UDRE
rjmp usart_tx
out UDR,r17
ret

;*************************

and set the settings in hyper terminal as

baud rate:2400
flow control:none

;********
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