int16_t i2cm_rcv(uint8_t slav_adress)
{
int16_t data=-1;
TWCR =(1<<TWINT) | (1<<TWEN) | (1<<TWSTA);
while(!( TWCR & (1<<TWINT) ) );// wait for SLA+R ack
TWDR = (slav_adress << 1) | 1 ; /* addr=1 + read */
TWCR = (1<<TWINT) | (1<<TWEN) ;
while(! ( TWCR & (1<<TWINT) ) );
if(TW_STATUS == TW_MR_SLA_ACK) {
TWCR = (1<<TWINT) | (1<<TWEN) ;
while(! ( TWCR & (1<<TWINT) ) );
if(TW_STATUS == TW_MR_DATA_NACK) { /* nack because last byte */
data = TWDR;
}
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) ;//transmit stop condition
wait_4cyc(100);
}
else {
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) ;// transmit stop condition
wait_4cyc(100);
}
return data;
}
void recv(void)
{
uint8_t i;
uint16_t c=0;
uint16_t d=0;
data_Z();
clk_Z();
if (read_data())
printf("burp\r\n");
/* wait_4cyc(WAIT_KBD_CYCLE4); */
/* wait_4cyc(WAIT_KBD_CYCLE4); */
/* wait_4cyc(WAIT_KBD_CYCLE4); */
clk_0();
wait_4cyc(WAIT_KBD_CYCLE4);
for (i=0; i<8 ; i++) {
if (read_data())
c |= 1 << i;
clk_Z();
wait_4cyc(WAIT_KBD_CYCLE4);
if (read_data())
d |= 1 << i;
clk_0();
wait_4cyc(WAIT_KBD_CYCLE4);
}
// parite
clk_Z();
wait_4cyc(WAIT_KBD_CYCLE4);
clk_0();
wait_4cyc(WAIT_KBD_CYCLE4);
// ack
clk_Z();
data_0();
wait_4cyc(WAIT_KBD_CYCLE4);
clk_0();
wait_4cyc(WAIT_KBD_CYCLE4);
// stop
clk_Z();
data_Z();
wait_4cyc(WAIT_KBD_CYCLE4);
clk_0();
wait_4cyc(WAIT_KBD_CYCLE4);
clk_Z();
printf("%x\r\n", c);
printf("%x\r\n", d);
wait_4cyc(2*WAIT_KBD_CYCLE4);
while(1);
}
// Receive a frame from an address
// Slave must respect the i2c_ryder protocol : first byte tells if there are
// data to transmit or not
// Return number of read bytes
uint8_t i2cm_rcv(uint8_t slave_addr, uint8_t n, uint8_t* data)
{
int i;
I2C_START();
// Slave address + Read bit (1)
I2C_SEND((slave_addr<<1)+1);
// No ACK, no data
if( TW_STATUS != TW_MR_SLA_ACK )
{
I2C_STOP();
wait_4cyc(100);
return 0;
}
// First byte: is there something to transmit?
I2C_ACK();
if( TWDR == 0 )
{
I2C_NACK();
I2C_STOP();
wait_4cyc(100);
return 0;
}
// Read all data
for( i=0; i<n; i++ )
{
I2C_ACK();
data[i] = TWDR;
}
I2C_NACK();
I2C_STOP();
wait_4cyc(100);
return 1;
}
// Send a n-byte data frame to an address
void i2cm_send(uint8_t slave_addr, uint8_t n, const uint8_t* data)
{
int i;
I2C_START();
// Slave address + Write bit (0)
I2C_SEND(slave_addr<<1);
// Data
for( i=0; i<n; i++ )
{
I2C_SEND(data[i]);
}
// Stop and wait
I2C_STOP();
wait_4cyc(100);
}
// Receive one data byte from an address, -1 on error
int i2cm_rcv_single(uint8_t slave_addr)
{
I2C_START();
// Slave address + Read bit (1)
I2C_SEND((slave_addr<<1)+1);
// No ACK, no data
if( TW_STATUS != TW_MR_SLA_ACK )
{
I2C_STOP();
wait_4cyc(100);
return -1;
}
// First byte: is there something to transmit?
I2C_ACK();
return TWDR;
}
void i2cm_send(uint8_t adress, uint8_t data)
{
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA);
while(! ( TWCR & (1<<TWINT) ) );
TWDR = (adress << 1) | 0 ; /* addr=1 + write */
TWCR = (1<<TWINT) | (1<<TWEN) ;
while(! ( TWCR & (1<<TWINT) ) );//wait for ack
TWDR = data;
TWCR = (1<<TWINT) | (1<<TWEN) ;// send data
while(! ( TWCR & (1<<TWINT) ) );// wait for ack
TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO) ;
wait_4cyc(100);
}
