firstoption
Newbie level 6
- Joined
- Jan 21, 2013
- Messages
- 14
- Helped
- 0
- Reputation
- 0
- Reaction score
- 0
- Trophy points
- 1,281
- Activity points
- 1,451
Good day to all,
Please I need help on how to write the Clock Code for my Slave device. I understand that only the Master device can generate the clock signal while slave device will listen to the incoming signal however I do not know how to implement this concept in the slave program such that the slave can equally send data to the master. I would be very glad if somebody can help me out. Below are my lines of code for both the Master device and the Slave device.
MASTER DEVICE ATTINY4313
SLAVE DEVICE ATTINY 2313
Thank you all for the usual support .Best regards.
Please I need help on how to write the Clock Code for my Slave device. I understand that only the Master device can generate the clock signal while slave device will listen to the incoming signal however I do not know how to implement this concept in the slave program such that the slave can equally send data to the master. I would be very glad if somebody can help me out. Below are my lines of code for both the Master device and the Slave device.
MASTER DEVICE ATTINY4313
Code:
#include <avr/io.h>
#include <util/delay.h>
/* SPI port and pin definitions.*/
#define _BV(bit) (1 << (bit))
#define OUT_REG PORTB //!< port output register.
#define IN_REG PINB //!< port input register.
#define DIR_REG DDRB //!< port direction register.
#define CLOCK_PIN PINB2 //!< clock I/O pin.
#define DATAIN_PIN PINB1 //!< data input pin.
#define DATAOUT_PIN PINB0 //!< data output pin.
unsigned char Transmitt_Receive_Master(unsigned char data);
void SetClock()
{
PORTB |= (1 << PINB2);
}
void ClearClock()
{
PORTB &= ~(1 << PINB2);
}
void SetData()
{
PORTB |= (1 << PINB0);
}
void ClearData()
{
PORTB &= ~(1 << PINB0);
}
void Spi_Master_Init()
{
// set up SCK/MOSI as output Pins
DIR_REG |= (1<<DATAOUT_PIN) | (1<<CLOCK_PIN);
DIR_REG &= ~(1<<DATAIN_PIN); // Data-In (MISO) AS input
}
int main(void)
{
Spi_Master_Init();
while(1)
{
Transmitt_Receive_Master(20);
}
}
unsigned char Transmitt_Receive_Master(unsigned char data)
{
unsigned char i;
unsigned char ReceivedValue=0;
for (i=0;i<8;i++)
{
if (data & _BV(i))
{
SetData();
}
else
{
ClearData();
}
data <<= 1;
// set clock high
_delay_ms(100);
SetClock();
ReceivedValue <<= 1; //shift left one bit
if (IN_REG & DATAIN_PIN )
{
ReceivedValue |= _BV(i);
}
else
{
ReceivedValue &= ~_BV(i);
}
ClearClock();
}
return ReceivedValue;
}SLAVE DEVICE ATTINY 2313
Code:
#include <avr/io.h>
#include <util/delay.h>
/* SPI port and pin definitions.*/
#define _BV(bit) (1 << (bit))
#define OUT_REG PORTB //!< port output register.
#define IN_REG PINB //!< port input register.
#define DIR_REG DDRB //!< port direction register.
#define CLOCK_PIN PINB2 //!< clock I/O pin.
#define DATAIN_PIN PINB0 //!< data input pin.
#define DATAOUT_PIN PINB1 //!< data output pin.
unsigned char Spi_Slave_Init()
{
DIR_REG |= (1<<DATAOUT_PIN); // Set up MISO as output Pins
DIR_REG &= ~(1<<CLOCK_PIN); // Clock-Pin aS input
DIR_REG &= ~(1<<DATAIN_PIN); // Data-In (MOSI) AS input
}
void SetData()
{
PORTB |= (1 << PINB0);
}
void ClearData()
{
PORTB &= ~(1 << PINB0);
}
unsigned char Transmitt_Receive_Slave(unsigned char data)
{
unsigned char i;
unsigned char ReceivedValue=0;
for (i=0;i<8;i++)
{
if (data & _BV(i))
{
SetData();
}
else
{
ClearData();
}
data <<= 1;
// set clock high
_delay_ms(100);
ReceivedValue <<= 1; //shift left one bit
if (IN_REG & DATAIN_PIN )
{
ReceivedValue |= _BV(i);
}
else
{
ReceivedValue &= ~_BV(i);
}
}
return ReceivedValue;
}
int main(void)
{
DDRD =0xFF;
Spi_Slave_Init();
while(1)
{
PORTD = Transmitt_Receive_Slave(40);
}
}Thank you all for the usual support .Best regards.